Horticulture

The indices of specific identity according to Jaccard were also calculated, expressing the concordance of the species composition of the zoocenoses compared to each other. Within the evaluation of individual years, types of management systems and crops, in 2018 the value was 75.00%, in 2019 their value represented 44.00% and in 2020 it was 50.00%. The total value with the comparison of both types of management for the observed period reached the value of 60.00%. Calculated values of dominance identity according to Renkonen, when comparing ecological vs integrated management for 2018 were 87.53%, in 2019 they were 92.55% and in 2020 they were 83.96%. The average comparison summary of the identity of dominance for the observed period of ecological vs integrated management represents 90.39%. No significant differences were observed when comparing values of diversity index according to Shannon-Weaver. The value for the ecological type was 0.9957 and for the integrated 1.0184, which is realistic when comparing farming in both types of agrocenoses. In terms of the ecological demands of individual species, the communities consisted mainly of species typical to lowland farmland ecosystems, where these species occur mainly in close coexistence of their reproductive cycle, nft hydroponic the presence of the relevant crop and management.

Subsequently, their occurrence is also influenced by local soil and moisture conditions, but it can be stated that the presence of the monitored Carabidae family is a reflection of relatively complex relationships taking place in agroecosystems. It is typical for species of the Carabidae family that they either have fully developed wings, resp. wings are completely or partially reduced. This is associated with restriction or complete loss of movement, which plays an important role in the migration of individuals to the environment. 85% of macropterous and only 15% of brachypteran species were present in the monitored group, which is evidence of a relatively large migration of individuals. When evaluating ecological valence and their association with the environment, 19 species can be classified as eurytopic, 4 for xerophilic, 3 for hygrophilic and 1 species acts as a halobiont. Based on a graphical comparison of ecological vs integrated farming system, using the f-test shows that the ecological type of farming recorded a higher number of Carabidae individuals on the monitored crops, with the exception of Harpalus rufipes on Medica sativa. It can be stated that on the basis of the f-test, which shows zero hypothesis results, the ecological impact of farming within the monitored crops was significant. Based on the analysis of variance , which expresses a graphical comparison of both types of farming, the results were in favor of the ecological type, which represents a higher abundance in all crops.Based on the results obtained, it can be stated that loss of biodiversity has now become a global problem. Much of the biodiversity of terrestrial ecosystems is ‘‘hidden” in the soil.

Using an experimental system to change soil levels of biodiversity and community composition has shown that declining numbers of soil organisms cause a reduction in multiple ecosystem functions, including biodiversity, suggesting that biodiversity is a key resource for ecosystem functioning . Carabids are efficient bio-indicators in terrestrial ecosystems because of their adaptability and ability to colonize almost all terrestrial habitats and geographical locations, their quick response to environmental changes, the ease in collecting them, and their relatively stable taxonomy. They are also useful organisms in agroecosystems due to their role as predators of crop insect pests and slugs, thus reducing their populations . Preserving high biodiversity in agroecosystems makes agricultural production more sustainable and economically viable. Which is also confirmed by the results we found, when during the monitored period 7 801 adult carabides belonging to 26 species were recorded. Intensified production, increased use of pesticides and fertilizers are under constant criticism. Agriculture is looking for other biological and agrotechnical methods to meet the requirements of global food production . Agricultural ecosystems are exposed to heavy burden during the year, however the composition of epigeic groups shows significant stability and homogeneity. The species richness of agroecosystems almost always exceeds the species richness of natural, resp. semi-natural landscape . Carabidae, with their abundance and functionality, represent a dominant group involved in reducing the number of pests in agroecosystems .

Carabidae are a taxonomically stable and well studied family, because of their specific life strategies and ecological preferences in terms of humidity, temperature, shading, soil and vegetation . They are efficient bio-indicators in terrestrial ecosystems because of their adaptability and ability to colonize almost all terrestrial habitats and geographical locations, their quick response to environmental changes, the ease of collecting them, and their relatively stable taxonomy . The total number of Carabidae in both types of farming is also 7 801 individuals, of which 4 784 were in organic and 3 017 in integrated farming.The Carabidae, Staphylinidae, Coccinelidae families are natural enemies of aphids and play an important role in agroecosystems. Predatory beetles play their role primarily in ecologically grown crops . By their presence, Carabidae species reflect the current topical, environmental and trophic conditions of agroecosystems, at the same time they act as part of the transport mechanisms of substances and energy and react sensitively to changes in agroecosystems and are a proven model group. Thanks to their biodiversity, they are suitable for detecting the effects of natural and anthropogenic disturbances . There are seventy-nine species of ground beetles recorded at the study sites of Slovakia according to authors . Ecological management systems are characterized by a larger floristic area and consequently faunistic biodiversity, compared to integrated systems, which provide suitable conditions especially for shade-loving species. However, it can not be excluded that if integrated systems are managed properly, they can increase biodiversity . The level of biodiversity of agroecosystems depends on vegetation cover, sowing process, management intensity, and also on factors that contributed to the influence of biodiversity within the monitored types of management, which is confirmed by our findings . Most Carabidae species belong to the group of predatory generalists or polyphagous, but are also narrow within this family specialists who prefer specific prey or plant food .

The distribution of present species is applied by the temperature, soil type, humidity, trophic relationships, sufficient food, mutual competition and all of it varies depending on the nature of the biotope. In addition to natural factors, an anthropogenic factor is also applied in agroecosystems, e.g. in the form of tillage, crop structure, cultivated crop, and applied inputs . It is necessary to highlight the rich network of their trophic relationships and ties, which is the main mechanism that ensures the balance of monitored agroecosystems. In terms of the ecological demands of individual species, their communities consisted mainly of species typical of lowland field ecosystems, where these species occur mainly in close coincidence of their reproductive cycle, the presence of the relevant crops and management. Subsequently, their presence is also influenced by local soil and moisture conditions, but it can be stated that the presence of the monitored Carabidae family is a reflection of relatively complex ongoing relationships in agroecosystems. It can be stated that Carabidae species are effective bioindicators within agroecosystems, they are adaptable, able to colonize all terrestrial habitats and at the same time they are useful organisms in agroecosystems, also due to their role as predators of cultivated plant pests, thus reducing their populations. An important role also belongs to the other granivorous, consuming weed seeds. They perform ecosystem services in the form of pest control and weed seed destruction . Harpalus rufipes was the eudominant species in all variants. It can migrate both by ground and by air, enabling large aggregations to form in areas with optimal hydrothermal regime and high aggregations of food . Harpalus rufipes is a trans-palearctic, polyzonal, habitat generalist, and is usually the most numerous ground beetle species in agricultural ecosystems and forest plantations . Due to the complex of adaptations and migratory abilities, it achieves the mentioned high values of abundance. It can be found in an extremely wide range of terrestrial ecosystems, with a particularly high population inhabiting an anthropogenically transformed environment. It is distinctive by the consumption of a wide range of foods, it is distributed in Central and Eastern Europe and was introduced to North America. Under the influence of various factors, this species of ground beetles can form aggregations up to tens and hundreds of individuals per square meter.Theabundance of carabids was not significantly different under the two management systems.

Harpalus rufipes and Poecilus cupreus were the most captured species. These results coincide with the data collected across Europe by other authors . Despite the disruptions of agricultural operations, the populations of carabids in arable crops have been found to be relatively constant. Pitfall trapping conducted from 1973 to 1981 in an arable field showed that the peak capture of H. rufipes, H. aeneus, P. madidus, P. melanarius and N. brevicollis remained relatively constant . The majority of species inhabiting agricultural fields have greater dispersal ability, often by flight, nft system are generally eurytopic, and are thus better adapted to living in unstable or temporary habitats. Species typical to arable fields are included in this group . Agricultural practices such as the application of insecticides that remove prey, or habitat destruction, may have a suffificient impact to create unfavourable conditions for Carabidae, but these impacts may not be long lasting, due to reinvasion or relatively quick dispersal distribution. In recent years the declining value of arable crops, combined with pressure from environmental organisations and consumer groups, has driven farmers to look more closely at integrated crop management and integrated farming techniques. Lower insecticide usage and choice of selective insecticides, non-inversion tillage and augmenting non-crop habitat are likely to have the greatest impact on Carabidae . Carabids have frequently been used to compare biodiversity in ecological and integrated management systems. Much evidence shows how agroecological practices can mean that ecological systems have less of an impact on carabid habitats than integrated ones. Some soil management practices such as reduced tillage or cover cropping can considerably influence the effects of organic management on carabid biodiversity . The Shannon-Weaver index, which we consider sufficient, was used to evaluate species diversity. However, species diversity can also be assessed using the Hill index . The susceptibility of some carabid species to insecticides, herbicide use through modification of plant cover and microclimate, and soil cultivation, has ensured that they are also frequently monitored in farming system studies. Studies have frequently found that differences between farming systems are relatively small compared to results between multiple years, fields and farms systems. This is because carabids exhibit considerable natural temporal and spatial variation . Some soil management practices such as reduced tillage or cover cropping can considerably influence the effects of organic management on carabid biodiversity. Normally, low-input practices make organic systems overall more eco-friendly and sustainable than conventional ones, although sustainability is important, not only from a short-term perspective, but also taking into account a long timeline.Ground beetles living in anthropogenic environments have a wider environmental tolerance than species in natural habitats. They achieve high local density due to anthropogenic activities such as agriculture, urbanization or forestry .

The interview was conducted by starting with a conversation to retrieve some basic information, such as the socio-structural characteristics of the farm, and it then proceeded to the Q sorting phase. This was carried out by making a sign with the grid, which was completely white so as not to influence the respondents, and providing them cards with statements.Each interview lasted between 45 minutes and 90 minutes. The interviews were carried out based on the respondents’ knowledge of PFTs, and they were conducted during three agricultural fairs, one in Bologna , one in Rome and one in Matera . The interviews were conducted in a face-to-face manner through the use of a poster. Based on the traditional scheme, this format has favoured the Q sorting phase. The composition of the sample defined itself through the filter question “In my opinion, precision farming is…“, and the number of interviewees was defined a priori by the authors in a manner consistent with Watts and Stenner,who reported that the number of respondents should be less than 70, representing nearly half of the selected items. Phase 4, Q sorting, is the moment when the interview takes place. All participants received detailed instructions to complete the questionnaire together with the statements and a card for the socio-demographic data. Initially, the participants classified the declarations about “In my opinion, precision farming is…” into three groups and subsequently ordered these in slots of an almost normal forced choice distribution of 9 total points on paper , ranging from “completely disagree” to “neutral” to “completely agree” .

In this way, the numbers of the Q sample items are recorded in the slots that replicate the distribution of the items for each of the Q sorts .The QM allows us to identify some common factors in individuals’ perceptions of the PF theme. The intercorrelation matrix was realised through the centroid procedure,flood table translating the solution through the use of varimax rotation, which is considered the best solution for the QM . Subsequently, through the criterion of eigenvalues greater than one , 5 factors were selected, and the characteristics of the factors are presented in Table 2. The five groups of discourses we discovered are shown in Table 3. The factor scores are the result of weighted averages of the values given to each statement during the Q sorting phase. In Table 2, the Z scores are converted into the original scale values to provide a clearer representation . The five discourses were analysed by examining the statements that most represented the discriminating points or the points of contact between the different perspectives. Once this had been done, it was possible to define the discourses as follows: Discourse 1: “The key to success” Members of this group strongly agree that PF is the use of new technological tools in agriculture to increase product quality and yields and that it gives the adopter a competitive advantage. These respondents do not think that PF is too complex for their knowledge or experience, and they do not associate the use of new technological tools with economic risk that is too high for their business. The entrepreneurs in this group do not think that PFTs are technologies that involve only young farmers or that they are a very widespread technology in their territory and in the Italian sector. They agree on the fact that PFT are a technology that supports decisions by monitoring their activity, and they think that PFTs develop in the presence of innovation services.

The members of this group agree on thinking that PFTs are a technology that supports their decisions by monitoring their activity and strongly believe that they would be impossible to use without a computer or an internet connection. They strongly agree with the fact that PF is a strategy that can be pursued only through the development of an environment that sees the collaboration of research institutions, the territory and the agricultural world, and in contrast, they do not consider producer organisations to be a necessary element to achieve it. PFTs are considered an easy-to-use technology that does not involve only young farmers. The farmers in this group do not see PFTs as a suitable technology for large companies, and they do not think that they are difficult to implement without financial support such as bank loans. They strongly disagree with the fact that PF is difficult to enforce in the agroecological context in which they live, and they connect the use of PFTs with major environmental sustainability. Discourse 3: “Something far from me” The entrepreneurs in this group agree that the use of new technological tools in agriculture can increase their yields and the quality of their products. As PF is considered too complex for their knowledge and experience and impossible without a computer or an internet connection, they think that PF requires organisational and structural adaptations that are difficult to implement and that a producer organisation is not enough to practice it. The members of this group do not consider PFTs to be a widespread technology in their territory or in the Italian agricultural sector. PF is not considered relevant to their current practices, and they do not feel that PF could improve the working conditions of the employees in the company. Discourse 4: “I don’t really realise the usefulness” The farmers in this group strongly consider PF to be a practice that fits their business model and that can make their job easier to carry out, even if it is not easy to understand how it works. They are the only respondents to strongly think that PF is a widespread reality in the Italian agricultural sector and that it can develop without the presence of innovation services.

The entrepreneurs in this group consider it the use of new technological tools in agriculture to reduce production costs but not to be more environmentally sustainable, and for them, PF is associated with an excessive economic risk for the company. PF is not considered the use of new technological tools requiring training and information costs or support by economic and training measures. Discourse 5: “Yes, but no thanks” The members of this group consider PFTs to be an easy-to understand technology that is suitable for large companies, but they do not think they are relevant for their current practices or that they are widespread in their territory. They think that PFTs are difficult to implement without financial support and that they requires training and information costs. The necessary structural and organisational adaptations for this kind of activity are considered to be difficult to implement, but the farmers in this group do not consider external collaboration the only way that can be pursued. They strongly disagree with the fact that PF corresponds with the use of new technological tools to be more environmentally sustainable, but they agree with the use of these tools to increase yields. The aim of the work was to understand Italian agricultural entrepreneurs’ perspectives on PF to determine the role and strategic importance that PF tools could have for the sector. To achieve this aim, it was necessary to explore the sphere of the self. To measure the role of farmers’ sphere of the self in the adoption process, this paper proposes the use of the QM to identify discourses that could play a predominant role in the formalisation of the adoption process. From the analysis conducted through a quali-quantitative approach, 5 predominant perspectives that contain and summarise many of the barriers and drivers found in the literature emerged, highlighting how the complexity of use and the understanding of these innovative tools are the most important components from the entrepreneur’s perspective . The perspectives have elements of contact and strong differences. Discourse 1 is the only discourse that sees PFT as something that could give farmers a competitive advantage and the only discourse that sees it feasible when supported by a producer organisation.

Discourse 2 is the only discourse to strongly think that PFTs are a set of technologies that can increase the environmental sustainability of the company, while the others, especially Discourses 4 and 5, strongly disagree with this statement. Discourse 2 is also the only discourse that relies more on collaboration with others, rolling benches especially compared to Discourse 5. Discourse 3 includes those who consider PF too complex for their knowledge and experience and those who see it as the use of new technological tools in agriculture requiring organisational and structural adaptations that are difficult to implement. Their idea that PF is something difficult to achieve without equipment such as computers and the internet is shared with Discourse 2. Discourse 4 includes those who have the highest consideration of PF as a practice that fits their business model even if they have the strongest idea of it as a technology that is not easy to understand, and they are the only farmers to see it as a widespread reality in the Italian agricultural sector. He members of this discourse are the only ones who do not see it as the use of new technological tools in agriculture requiring training and information costs; furthermore, they have the lowest agreement on the fact that PF has to be supported by economic or training support measures. Discourse 5 is the only discourse that considers PFTs to be an easy-to understand technology that is suitable for large farms. They think that PF requires training and information costs and that it is a difficult activity to be carried out without financial support. Nevertheless, they have the strongest consideration of PF as a strategy that can be pursued even without the collaboration of institutions or other farms. The members of all groups consider PF to be the use of new technology to be more efficient by maximising the ratio between input and output to a slight extent. The extracted perspectives answer the research question we asked ourselves at the beginning of the work, that is, “precision farming for me is…”, delving into the cognitive sphere of entrepreneurs. Unlike other works in the literature, this study extends beyond the perception adoption link , but we try to outline those thoughts that can be useful to stakeholders and policy makers to better understand the PF phenomenon. The aim of this paper was “to colour the picture of farmers’ perception“, and the analysis provided five different “colours” to better outline the picture of the puzzle pieces.

Furthermore, it could be important to emphasise that the self-selected sample of respondents belonging to these 3 approaches is, on average, composed of young people , confirming studies reporting that the propensity for knowledge and adoption of new technologies in agriculture is a prerogative of young actors . This study highlights a possible lack of knowledge and information in the advanced age groups, who decided not to respond to our investigation and who, according to the literature, rely mainly on their experience rather than digital support in their farm management and rarely appear as experts in this kind of study. The QM could be a useful method for answering the question “What do farmers really think about PF?”, revealing in our results some relevant perspectives of Italian farmers and overcoming the limitations of qualitative and quantitative methodologies in studying the self. Given our results and in the context of innovation processes in agriculture, we believe that a mixed method, such as the QM, allows us to colour the piece of the cognitive sphere, which we have set ourselves to investigate. This opens the door for future developments to research to understand the interactions between the cognitive sphere and the other pieces of the puzzle to arrive at a more systemic and holistic understanding of innovation processes in agriculture. This analysis provides new contributions to the study of PF adoption, focusing all the attention on the perspectives of entrepreneurs rather than making another classification of the business types more or less inclined to adopt PFTs.

Recurring topics were the need for shorter value chains, more fairness towards farmers, and less dependence on migrant workers. However, we observed limited adaptive and no transformative responses. This might betray a general orientation towards robustness and attempts to avoid larger changes to the modes of operation. Similar to the results of other studies , our case studies found limited impact on the production and delivery of food and other agricultural products. This was due to either little exposure or the agile activation of robustness capacities of the farming systems in combination with an enabling institutional environment. While this constitutes a significant achievement, considerations during the crisis were almost exclusively limited to the productive functions of the system.Moreover, actors in the farming systems and the enabling environment generally focused on the immediate issues and gave little consideration to long-term implications and challenges. Hence, adaptive or transformative capacities were much less on display than coping capacities. The comparison of pre-Covid findings and the Covid-19 crisis mostly showed similarities. For instance, if challenges already loomed before the crisis, they persisted during the crisis, sometimes even to a larger extent.

Also, the focus on coping capacities was already visible before the crisis. In addition, led grow lights the comparison confirmed the eminent role of resilience attributes. For instance, in cases with high connectedness and diversity we found that these system characteristics contributed significantly to the ability to deal with the crisis. However, the findings during the crisis did not entirely reproduce pre-Covid findings, i.e. some cases experienced other challenges, were able to mobilise more responsive capacities than expected, or showed that already existing connectedness did not lead to adequate actions during the crisis. This illustrates the latent, multi-faceted and dynamic nature of resilience. The data only capture short-term responses to the immediate shock of the first wave of the pandemic and the ensuing restrictions. For instance, we did not assess whether online platforms were sustained. Experiences from later lockdowns during the second and third wave of the Covid-19 pandemic indicate that ‘many had to invent the wheel again’. This resonates with the observation that despite a long list of discussed topics, farming system actors did not use the crisis as a window to trigger more structural change. The only exception in our sample – the prohibition of subcontracting in German slaughterhouses – was forced upon the industry by the Ministry of Labour Affairs, which enabled a change that most observers felt was long due. More than one year into the crisis it becomes clear that the short-term shock evolves into long-term stresses, in particular at the macro-economic level of unemployment, public and private debt and reduced purchasing power. Sectors that are particularly affected also lose valuable resources, from skilled labour to missing investments and interrupted social and economic network connections.

It is plausible that the experience of labour shortages and the importance of digital platforms in developing coping strategies will accelerate trends towards automation and digitalization in the food and agricultural sector as in the general economy. The findings have important implications for policy making. First, the analysis demonstrates a need to strengthen anticipatory capacities at all levels, in particular the ability to recognise signals of impending threats, whether they are short-term or long-term . Second, the actors’ reflections in our case studies mostly betrayed a questioning of transnational value chains. Policy makers need to discuss openly whether regional and short value chains are indeed generally more resilient and should therefore become a policy priority. Third, the importance of resilience attributes iterates that system design matters and, thus, that being impacted by a crisis is not ‘just a matter of bad luck’. It needs to be discussed how resilience attributes, such as connectedness in value chains and diversity, can become a more integral part of policy design. Fourth, the convergence of pre-Covid and crisis findings demonstrates that the systematic resilience assessment of farming systems points at system vulnerabilities. This knowledge can directly feed into stress tests of food systems. Fifth, the Covid-19 crisis is likely to reinforce concerns about future pandemics from zoonosis and to raise awareness of the interdependence of animal, plant, environmental and human health. From a resilience perspective, such public health issues create system vulnerabilities that might require a transformation, in particular of animal-based farming systems. At the same time, our analysis indicates that the transformative capacity of many farming systems needs to be actively enhanced and stimulated through an enabling environment. This includes the provision of specific resources for a desired transition and formal and informal institutional arrangements that provide a clear sense of direction and that enable rather than impede transformations that are necessary to maintain public goods and services.

An important question for future research is whether the focus on short-term robustness just reflects the higher visibility and urgency of shocks compared to slow processes that undermine or threaten important system functions, or whether they betray an imbalance in resilience capacities at the expense of adaptability and transformability. Another task for research is the development of a systematic understanding how short-term crisis interventions to secure the provision of private goods can synergetically support transformations that are needed to address the broad range of challenges to public goods . Intensive farming practices produce cheap food, but are also criticised for impairing animal welfare, and for contributing to climate change, biodiversity loss, poor air quality, soil degradation, stench and the risk of zoonoses . Policy makers and citizens call for alternative, demand-oriented, and less intensive farming strategies, which generate a higher income for farmers and decrease the negative externalities of production . Farmers’ strategic decisions are done with regards to market integration, e.g., enlarge to stay competitive in the international market, or produce for smaller demand-oriented markets like organic. Yet, there has often been a mismatch between, on the one hand, societal and political preferences towards alternative farming strategies1 like organic, and on the other hand, observed farmer behaviour. In the past, implemented policies had unintended consequences. In the Dutch pork sector, for example, a governmental subsidy for pig farmers to convert to the organic market introduced around the year 2000 resulted in a higher increase in organic supply than the anticipated increase in demand for organic pork meat.

Excess supply resulted in dropped farm gate prices, pressure on organic farmers’ income, and a damaged reputation of organic farming as a good alternative to conventional among conventional pig farmers . In addition, while organic farming is generally seen by citizens and policy-makers as a viable alternative to conventional farming, farmers feel peer pressure to remain conventional or to defend their choice for alternative farming strategies like organic towards their peers . This shows a friction between societal preferences and farmer dynamics. In order to design an effective support strategy for alternative farming strategies, better understanding of the diffusion of alternative farming strategies is needed, in particular effects of market price dynamics and social interaction among farmers. Pig farmer decision-making is related to many factors, which can roughly be grouped into personal, contextual, and social factors . Personal factors that are associated with a higher chance to invest in stables in general are younger age and having a successor.Personal factors that are associated with investments in higher animal welfare or more sustainable stables are a positive attitude towards the alternative , higher innovativeness , and an idealistic farming style . Some of these factors are relatively static, i.e. a pig farmer’s innovativeness and a farmer’s farming style , while other factors are dynamic, i.e. age and attitudes.Contextual factors that influence pig farmers’ decision-making are the farmers’ investment rhythm and farm size. Farmers’ investment rhythm is determined by the useful life of an asset, such as the time that it takes for a stable to be depreciated, and the farmer’s opportunity rhythm to make a long-term change on his farm determined partly by the availability of a successor.

Farmers take into account their farm size as follows: the larger the size the more additional supply from the farm would affect the elastic organic market price; and therefore farmers with a large farm do not see organic as a viable alternative . Finally, social factors that influence investment decisions are norms, i.e. the behaviour and opinions of peers that can influence behaviour, and the status of farmers within reference groups. In a game environment, social interactions have shown to influence farmers’ strategic investments through opinion leadership . Also, in a study on the adoption of an alternative housing systems for sows, i.e. group housing instead of individual crates, those farmers who did not yet convert felt less peer pressure . The Social Identity Approach relates social interaction to behaviour change, through the social dimension of a person’s self-concept. The main idea behind the Social Identity Approach is that humans have a universal drive to evaluate their opinions and attitudes to increase their self-esteem and/or confidence and status as a group member . Individuals within a group are motivated to act according to the norms associated with being a member of the group,vertical grow system and disagreement in opinion or attitude between in-group members can result in attempts to reduce the disagreement through social influence . The Social Identity Approach states that the level of influence is based on similarity between self and other, i.e. whether they are in-group or out-group members; the similarity of the situational context between self and other; the status of oneself and the other within the group, i.e. the direction of influence; and the level of identification with the in-group . To understand and model influence between farmers, it is, therefore, important to know about similarity in person, situational context, and what gives status within a certain reference group. To identify Dutch pig farmers’ reference groups in the context of organic market conversion, we looked at previous findings and distinguish four reference groups. As shown above, pig farmers take into account their farm size when considering conversion to an added-value market . Therefore, the first reference group consists of farmers who are similar in farm size. Second, organic and conventional farmers opposed each other’s’ practices in the past . Therefore, the second reference group consists of farmers producing for the same market. Third, previous research identified three farming styles that have been relatively stable over time in the Dutch pig farmer population: idealists, craftsmen and entrepreneurs.

They differ in their definition of ‘being a good farmer’ and in status symbols, those factors that give farmers a high status within their farming style reference group . Idealists see pig farming as a way to earn a living instead of a way to maximise profits, and they like to keep investments low . In addition, they value farming methods that incorporate the intrinsic needs of animals into farm design and management. They oppose conventional farming methods that are harmful to animal welfare and think that behaviour of conventional farmers contributes to current societal criticism regarding the Dutch pig sector . Both craftsmen and entrepreneurs opt for maximising profits instead of maintaining a livelihood . Craftsmen gain profits through high productivity, e.g. intensification through increasing litter size and/or daily growth, while entrepreneurs optimise farm management, farm scale and market integration . The latter two oppose the idealistic worldview. Therefore, the third reference group consists of farmers with a similar farming style. Finally, innovative farmers, as opposed to conservative farmers, are more open to new ideas and alternative investments as described above. We, therefore, assume in the remainder of this article that farmers who are more innovative have a different reference group than their conservative colleagues: conservative farmers’ reference groups are similar farmers , while innovative farmers’ reference group are farmers who are higher in status . Therefore, the fourth reference group consists of farmers who are higher in status according to one’s own farming style. For example, the reference group of innovative farmers with an entrepreneurial farming style are all farmers who earn a higher income than themselves regardless of farming style, farm size or market. This will be further outlined under ‘interaction mechanism’ below.

In 1994 permanent subsidies for organic farming were implemented . This was extended in 1996 where additional funding was provided for advice to farmers in the transition phase. At the same time subsidies for development initiatives were also given by the state for processing, marketing and distribution of organic products. Denmark also invested into schools, institutions and universities to educate farmers, increase knowledge and product development.Currently the Danish government provides farmers with subsidies for conversion and maintenance of organic farming . To encourage organic farming in Austria the government implemented several subsidies and incentives to help create the image of “Ecoland Austria”. “Without a doubt, the organic farming boom in Austria was caused by government subsidies distributed on a federal scale” . This is confirmed by Musshoff and Hirschauer , who stated that financial subsidies increased the willingness of farmers to convert. In 1989 three Austrian provinces started to provide subsidies to individual farmers for switching to organic farming. In 1991 the Federal Ministry of Agriculture and Forestry stimulated the growth by introducing subsidies and an incentive program. Grants for organic farming associations and national conversion subsidies were implemented. Also, during and after conversion,hydroponic dutch buckets assistance was given to the farmer . In 1992 these subsidies where supplemented by a program which supports organic production for existing producers .

After entering the EU in 1995 Austria implemented a new agri-environmental program: ¨ OPUL. This five-year national aid program encouraged conversion and maintenance of organic farmers.Respondents in Denmark indicated both farming conditions and stakeholder cooperation as highly relevant. For policy development of the sector it was very important that there was little competition between farm organizations. Consensus between parties on organic support and resource availability for the organic sector eases the establishment of new policies . Besides this, the development of the Danish Agriculture and Food Council has linked the interest of the organic sector with the agricultural sector. The association considered the interests of all parties as consumers, ministries and industrial organizations . The close cooperation between the organic agricultural sector and the Danish Agriculture and Food Council led to positive features. It increased the dissemination of new knowledge, establishment of advisory services and development of organic policies . In this paper, we analyzed potential barriers for upscaling organic dairy farming in the Netherlands and making a comparison with organic dairy in Austria and Denmark, two EU countries that have shown a strong growth in organic dairy farming. Here we first discuss the findings from the TIS analysis and the diffusion of organic dairy, while in the second part we discuss the larger ramifications with respect to a sustainability transition in agriculture.

In TIS, the functioning of an innovation system is analyzed in relation to the transition phases of the innovation process . Typically, in the early phases of development, the functions guidance of the search, market formation, resource mobilization, and counteract resistance to change may hamper the further upscaling if they are not positively fulfilled. In the final acceleration phase, where the innovation diffuses into the socio-technical regime, barriers in market formation may hamper diffusion . Additionally, Schiller et al. identified various interdependencies amongst the TIS functions in agroecological food systems, and as such weaknesses of functions could cascade throughout the whole innovation system. Based on the barrier analysis, our results of Dutch organic dairy farming indicate that the functioning of guidance of the search, entrepreneurial activities, resource mobilization and market formation are hampered by various barriers that lead to an arrested diffusion of organic dairy farming. The lack of diffusion in the Netherlands can be explained first by a weak governmental support. The introduction of organic farming in the Netherlands in the 1990s occurred during a time of large policy reforms at the Ministry of Agriculture, triggered by a neoliberal political discourse that is still visible today . One example of this was a separation between policy making at the Ministry on one hand and implementation through privatized organizations on the other hand. This had impacts on agricultural research and education and led to a larger emphasis on technical solutions, export orientation and competitiveness of the agricultural sector . During the early 1990s organic farmers were strongly limited in their abilities due to the privatized networks of institutes and agribusiness and these hurdles were not solved by the Ministry .

As can be found in many newspaper articles published in the early 2000s, critics of organic farming saw the possible diffusion of organic agriculture as a step back. As such, the organic niche had to prove itself on a competitive market without much public support. The lack of explicit policy support in the Netherlands can also be illustrated by the many newspaper articles that dealt with environmental issues such as the long history of persistent manure problems in livestock farming, and this problem was reinforced after the abolishment of the milk quota in 2015. As a result the long-term negotiated derogation on manure application at the EU-level by the Dutch government came under political pressure. Because livestock density is lower on organic farms it adds less to the problem. Yet, governmental decisions to cut emissions were not alleviated for organic farmers. The governmental laissez-faire demand-side support towards organic farming and the strong belief that organic farming should grow by mainstream market mechanisms without niche protection was also reinforced by the incumbent regime. Repeatedly newspaper articles mentioned the resistance from the Dutch farmers association LTO to provide concrete measures to support organic farming. In contrast, Austria and Denmark applied supply-side support to organic dairy farming. In for example Denmark, explicit government support towards organic dairy can also be illustrated in relation to the use of pesticides by conventional farmers. Here, the Danish government found that this use was threatening the groundwater wells, and decided to tax pesticide use while tax revenues were used to further support organic farming . As such, the Danish government created a new level playing field between conventional and organic dairy farmers, making it more attractive for farmers to produce organic. Second, regarding resource mobilization the Dutch government only developed demand side policy instruments that mainly addressed knowledge development on market formation.

The Dutch government did not use CAP payments to support organic farming during transition and national transition subsidies were already phased out by 2002. Respondents indicated the high agricultural land prices in the Netherlands to be a barrier for transition. Indeed, agricultural land prices1 are about 6 times higher in the Netherlands compared to Denmark and Austria2 , and are the highest in Europe. Moreover, in the past organic farmers also indicated problems with additional labor force since organic farming is more labor intensive. Although from its onset the organic policy in Denmark was also demand side driven, it gradually shifted by 1995 towards a supply side approach to support farmers during and after the transition . Currently both in Denmark and Austria farmers are supported by transition subsidies and maintenance payments, using measure 11 of the European Agricultural Fund for Rural Development . Both respondents and literature suggest resource mobilization remains a critical issue to retain organic farmers, as many would shift back to conventional farming due to higher costs . Indeed, according to the annual report of Skal in 2019, 24% of the Dutch farmers that ceased organic farming indicated this for financial reasons . Third, the weak organic market formation in the Netherlands is probably related to the higher consumer prices. In a study on the repeated purchase of organic products, Marian et al. indeed found high prices to be an obstacle to consumers. However, high prices alone did not explain the low repeated purchase in their study. In conventional products, high prices are usually perceived as a quality cue . This is not always the case for organic products and consumers may perceive high prices as additional costs rather than quality improvement . To gain more repeated consumer purchase, Marian et al. suggested to further differentiate organic products through branding. To illustrate the effects of such a brand differentiation, the sustainable coffee market in the Netherlands can serve as an example. Here, certified coffee together reached a market share of 45% in 2010 .

The rapid market creation was the result of a competition between different brands on the market and the rivalry of multiple certification systems . Importantly here, retailers started to push the ‘less sustainable certification label’ as a standard brand in their collection. This also had positive effects on the purchase of more stringent coffee labels as discussions amongst coffee market leaders and retailers arose on the sustainability aspects, which led to an increased market share of all labels . This diversification approach is recently also applied to fresh domestic produce in the Netherlands. For example the market share of the new label “On the way to Planet proof” has grown 492% between 2018 and 2019 . The approach shows a strong growth of total market share of sustainable produced dairy to more than 15% in 2018, although the specific sustainability criteria of the various types of certification differ from organic.To conclude, our barrier analysis on the functioning of Dutch organic dairy farming innovation system thus indicates that the current development is more associated with the early phases of the transition than with a late transition stage . In contrast, in Denmark and Austria the diffusion of the organic market is in an acceleration phase, illustrated by exponential growth of organic purchase per capita since 2000 . It is suggested that in both Denmark and Austria mass distribution of organic dairy by large retail is the main driver of the diffusion and have led to smaller consumer price differences, bato bucket but to a much lesser extent in the Netherlands where large retail contributes to around 50% of total organic sales . In Austria and Denmark also strategic marketing campaigns were developed targeting regional origin , or health issues . Recently, agricultural transitions have been studied using the MultiLevel Perspective , drawing on earlier research conducted on the energy transition . However, agricultural sustainability transitions might be fundamentally different in comparison to the more ‘technology driven’ energy transition. First, farming is a land based activity where innovations such as organic practices are very often developed by regime actors who switch to alternative practices to challenge the incumbent sociotechnical regime, and not by the challenges of newcomers . This is referred in the transition literature as a ‘regime transformation’.

A regime transformation can occur through an accumulation of novelties in niche spaces that allow for radical practices to emerge , in which novelties are strongly related to so-called second order innovation changes in which pressure is put on the incumbent regime . Niches are the outcome of various processes, including knowledge development and sharing and social embedding that may lead to the certification of practices through standards, also to protect niches . To develop niches further, appropriate incentives to actors need to be in place, such as taxation systems or regulatory support . In addition, governments can facilitate niche development through financial support, a purchasing policy of certified products to increase market share, and active interventions at international declarations of intent with various market actors in the case of international commodities . Second, farming takes place in spatially diverse settings with very different farm structures resulting in different ‘transformation pathways’ . Various certification labels may be able to tackle these different settings through specialization and diversification of sustainability criteria . Indeed, motives and pathways towards sustainable farming may differ considerably between regions and farm types . In some areas organic farming might be a solution to the low competitiveness of family farms that produce under sub optimal conditions , in other regions, like in the Netherlands or Denmark, it may motivate farmers to escape the ‘productivist’ paradigm of conventional farming competing on world markets . Third, a sustainability transition in agriculture based on for example organic principles, is much less driven by technological improvements as they include mostly extensification of practices, leading to agricultural products that are always more expensive to produce than their conventional counterparts.

For example, in 2018 the share of total organic agricultural land, including arable farming and horticulture, was relatively low in the Netherlands, but much larger in Denmark and Austria, respectively 9.8% and 24.7% . For dairy farming, the share of organic dairy cows in the Netherlands was 2.3% in 2017, and in respectively Denmark and Austria 12.3% and 21.2% . Although consistent and reliable statistics on organic markets and commodity breakdown is still non-existent,some organic consumption patterns show marked differences. In 2019 Danish and Austrian consumers purchased respectively € 344 and € 215 per capita on organic food, while Dutch consumers spend €71 per capita.Finally, the market share of organic dairy in 2019 was ca. 21% in Denmark, 16% in Austria and only 4.1% in the Netherlands .Within the full range of organic farming , each can be identified as single niches. Organic dairy farming therefore is a niche, and in transition studies niches are often defined as “protected spaces where new socio-technical practices can develop” .A transition is a long term, complex and multidimensional process, where a societal subsystem radically or incrementally changes . The sociotechnical regime is a central concept within transition research and defined as “a relatively stable configuration of institutions, techniques and artefacts, as well as rules, practices and networks that determine the development and use of technologies” . Sustainable transitions can be seen as a long-term goal, and therefore what is considered ‘sustainable’ can change over time. Changes within a regime occur at different dimensions such as technological, material, organizational, institutional, political, economic, and socio-cultural.

This is due to the fact that established technologies and practices are highly intertwined within these systems . As a result, numerous difficulties in the upscaling of organic dairy farming could be identified, related to organizational, ebb flow tray technological and knowledge exchange issues , power relations and a variety of other institutional problems . Innovation system frameworks have shown to be useful to study the transition of agricultural systems towards more sustainability . More specifically the Technological Innovation System is used to assess the barriers and drivers of a niche as it grows and institutionalizes to further challenge the existing regime . A TIS is defined as a set of networks of actors, infrastructure and institutions that jointly interact in a specific technological field that contribute to the generation, diffusion and utilization of variants of a new technology and/or a new product . Central to a TIS is that innovation and diffusion is steered both by individual and collective actions and as such includes an analysis of system functions. Next to mapping the structure of the innovation system , it is therefore important to identify the most important key processes that are needed to build up the respective innovation system . These key processes are coined in Hekkert et al. as the seven system functions and can be mapped throughout time in order to identify system dynamics . In this paper we apply the TIS framework to the Dutch case of organic dairy farming in order to understand what may hamper upscaling.

To identify potential leverage points, the development of the organic dairy sector in Denmark and Austria will be studied alongside as examples of countries in which the organic niche is much more advanced. For this study we use a mixture of information sources, i.e., a literature review, a newspaper review, and semi-structured interviews of key stakeholders within the organic dairy value chains from the Netherlands, Denmark and Austria. In the study of agricultural transitions, slight adaptations to TIS have been made in the past, such as the Agriculture Innovation System , where innovation is seen as an outcome of the different interactions between the actors, institutions, and the economic, environmental and societal systems and as such less focused on the development of new technologies but rather on organizational and institutional change . Indeed, the emphasis within the organic farming transition is not only about the technological aspects of the innovation, but also about the understanding of the system dynamics and performance of a system within the wider ‘conventional agricultural practices’ . As such, in the current study AIS was applied, while using the functional aspects of TIS. The TIS uses five steps to analyze the functioning of an innovation system based on Wieczorek and Hekkert , i.e., the analysis of the structural components of the system such as actors, institutions, networks and interactions, infrastructures , the functional analysis and the identification of system problems, and formulation of systemic instruments.

The analytical framework of TIS contributes to the understanding of the complex nature of the diffusion of a niche, such as organic farming, by analysing the obstacles that may block this process . As such, problems that are identified from the coupled structural functional analysis may hinder the diffusion of an innovation and are referred to as systemic problems . In this respect, Weber and Rohracher identified three types of failures of transformative change. i) Market failures that are linked to the niche level and may include leakage effects and the higher costs associated with sustainable production. ii) System failures that could affect infrastructures such as a lack of knowledge, capability problems such as competences, and institutional failures such as a regime that strongly hinders the uptake. This can be further divided into soft institutional failures that relate to habits and culture, and hard institutional failures that refer to laws and regulations that block the diffusion of an innovation. Finally, iii) transformation failures referring to directional failure by a lack of a shared vision, weak consumer support , policy coordination failure and reflexivity failure that signifies a lack of long term commitment and learning ability. To gain a better understanding and to identify the current state of development of the organic dairy sector, including value chain actors, first literature reviews were conducted on organic dairy farming in the Netherlands, Denmark and Austria. Literature searches were performed in Google Scholar, Science Direct and Scopus.This search string includes more than organic dairy since the research is focused on transitions rather than practices alone.

Related governmental documents and websites were also examined. Once theoretical saturation of the literature was achieved the results were used to formulate questions for interviews. Second, semi-structured interviews were conducted with interviewees in all three countries. Most interviews lasted between 30 and 60 min and were carried out face to face or over the telephone. In total 23 interviews were performed with experts of the organic dairy sector in the Netherlands, Austria and Denmark . The sample included representatives from governmental bodies, NGOs, universities, farmers, processors and retailers. The 13 Dutch interviewees were asked questions which were formulated around the seven functions of the TIS framework . To strengthen the solutions found in the literature review for Denmark and Austria, 10 interviews were held with experts within the Danish and Austrian agricultural regime. Questions were related to the seven functions, and the observed barriers. Also country specific solutions to barriers were identified and are further referred to as enabling factors. Most experts were found after a review of relevant policy documents from government and industry. Using snowball sampling subsequent interviewees were found. Finally other relevant stakeholders were found by visiting a trade fair . In total 63 experts were contacted . Third, the Lexis Nexis search engine was used to retrieve relevant Dutch newspaper articles, published between 1991 and 2018 on organic farming to get a better understanding of the public debates and discourses on organic farming in the Netherlands. The primary search using‘biologische landbouw’ resulted in 8157 newspaper items, though many of those are published multiple times in different imprints of national newspaper agencies, or published papers that did not have a link to Dutch organic farming . Based on relevant article headings and removing duplicates a corpus of 260 papers was retrieved as pdf documents. Within the corpus search strings such as ‘government’, ‘cabinet’, ‘Minister’, ‘organic policy’, ‘retail’, ‘supermarket’, and ‘consumer’ were used to retrieve relevant information.

The information flow of the different steps are depicted in Fig. 1. The grounded theory method was used to analyze the interviews. Grounded theory is “a systematic method for constructing a theoretical analysis from data”,flood and drain tray and as such an iterative process between data collection analysis and theory building . An initial coding framework for the barriers in the Netherlands was created through an iterative process in which the seven functions were used as categories. After the first interviews were transcribed the coding framework was created. An iterative comparison between the data and concepts was made to convert the verbal data into barriers. Adoptions to the framework were made until theoretical saturation was achieved. The coding framework for Austria and Denmark was created based on the enabling factors found in literature. After an interview was performed, the transcribed data was coded. The coding framework was adjusted when more interviews where established. By using this iterative process possible missing enabling factors were added into the coding framework. The barriers found through the coding process were further analyzed to provide the most common and important barriers. To decide which barriers were key in the development, a scoring system for the functions and barriers was developed. Every mentioned barrier was scored within the coding framework with value 1, if a respondent did not mention a barrier, the barrier got the value of 0. To calculate how often one barrier was mentioned, we divided the number of times a barrier was mentioned by the sample size and multiplied by 100%. The Dutch sample size was 13, the sample size in Denmark and Austria was 5. To calculate how often a function was mentioned we divided all mentioned barriers within a function to the total mentioned barriers and multiplied by 100%. Using a three-point Likert scale the priority of the various barriers was assessed. This scale divides the barriers in three levels of priority according to the number of times a barrier was mentioned by the respondents. If less than 33% of the respondents mentioned a barrier it was of low priority , between 34 and 66% the barrier was of medium priority and 67–100% was of high priority . Following this, each barrier was linked to one of the seven functions. To get a clear understanding which barrier resisted the development the most, the barriers starting from medium priority or higher within the most important functions were evaluated in the results.

After linking each specific barrier to the structure of the system, the systemic problem can be identified. This systemic problem will point at which function mostly hindering the development and upscaling of the organic dairy innovation system. Based on the interviews, 19 barriers could be identified, while these barriers were mentioned in total 92 times by the Dutch respondents. These barriers are linked to the seven TIS functions in such way that 7% of the barriers was associated with the function entrepreneurial activities, 5% with the function knowledge development, 0% with the function knowledge exchange, 34% with the function guidance of the search, 37% with the function market formation, 15% with the function resource mobilization and 2% with the function counteract resistance to change . Since 1991, in Europe, including the Netherlands, organic farming has been institutionalized by the EC Regulation 2092/91 . This regulation includes, amongst others, strict rules regarding use of fertilizers, pesticides etc., while the organic certification guarantees farmers a higher milk price. The share of organic dairy farmers in the Netherlands slowly increased from 1.1% in 2001 to ca. 2.9% in 2019. Milk production per cow is lower, but due to higher organic milk prices farmers receive a higher income per labor hour . Since 2013 organic milk prices are decoupled from conventional milk prices, which also resulted in a larger difference because conventional milk prices strongly dropped after the milk quota abolishment in 2015 and subsequently a larger supply.In 2020 organic farmers received 49.5 Euro per 100 kg milk, which is 12.5 eurocent higher per kg milk than conventional farmers.Because organic milk prices are less volatile, income of organic farmers is more stable.

In addition, this opens the possibility of customising the buffer species and mixtures added, so that the amounts or proportions of the positive  ion portion of the buffer delivered to the system may be adjusted or controlled by choosing buffer species or mixtures based on the buffering capacity of the negative ion. Conductivity continually increases in fish-only systems because of the build-up of ions which are produced as the by-products of fish metabolism. The inclusion of plants into recirculating aquaponic systems leads to active uptake of waste nutrients and ions by the plants, which counteracts the ionic build-up seen in fish-only systems. The efficiency of plants to take up nutrients and ions in hydroponic systems, and thus maintain zero conductivity accumulation within system waters, is dependent upon whether the correct mix and concentrations of those nutrients are provided. The conductivity curves  from the present study indicate that, in the final third of the experiment, plants within the mixed and potassium treatments maintained slightly lower water conductivities than observed in control or calcium treatments, although overall conductivities did not differ significantly between any treatments across the 21-day course of the research-scale experiment. This apparent lowering of conductivity levels in the last third of the experiment for the mixed and potassium treatments is probably since plants within these treatments had access to increased levels of potassium during their fastest-growing phase.

Potassium is an essential macronutrient to plants  and is known to play a key role in a plant’s ability to synthesise proteins and carbohydrates,and thus grow. Adler, Harper, Takeda, et al.  also argued that when other nutrients limit plant growth, nutrient removal can be increased by adding those nutrients that are most limiting, and therefore, rolling benches other essential nutrients  must be added to the aquaponic system. These nutrients typically include iron, manganese and potassium. The lowered conductivities in the two treatments containing higher additions of potassium  may suggest that the plants in these treatments had a slightly increased ability to achieve elevated carbohydrate and protein synthesis, thus allowing them to remove and assimilate slightly greater amounts of ions from the surrounding water medium and therefore, lowering the conductivity of the system water. This hypothesis also may be supported by the observation that lettuce plants within these two potassium-containing treatments exhibited the highest growth rates and yields  and exhibited the greatest removal rates of nitrate from recirculating waters. In terms of water use, results suggest that those treatments containing potassium were also more efficient,with significantly less water used by the potassium and mixed test treatments, when compared to the control treatment. Again, this result is probably correlated with the plant’s requirement for potassium to achieve carbohydrate and protein synthesis and subsequent growth. The plant’s requirement to transpire more water from those treatments not containing additional potassium may be explained by the fact that the plants may have been transpiring greater amounts of water to try and gain greater access to limiting ions, such as potassium. In conclusion, results from the present study suggest that, when using buffers for maintenance and control of pH in recirculating aquaponic systems, it is advantageous to use buffers with positive ion constituents that are essential to optimal plant growth. Parameters such as plant growth and yield, nitrate removal, conductivity and water use demonstrate that either a potassium-based buffer or a mixture of potassium and calcium-based buffers are the most appropriate buffers to use to achieve optimal plant growth efficiencies in the research-scale aquaponic system, whilst parameters such as fish growth and FCR, dissolved oxygen and pH maintenance are unaffected by the positive ion make-up of the buffer.

In addition, it is apparent from buffer use and pH maintenance parameters that the negative ion constituent of the buffer may affect the amount of buffer required. It is therefore recommended that this work be replicated at a commercial scale and through an entire fish production cycle and that future aquaponic researchers and industry individuals use buffers containing potassium as the positive ion constituent and consider periodically using calciumbased buffers to maintain pH in recirculating aquaponic systems.Plan factories are facilities that enable the year-round production of vegetables and other productions through precise control of the growth condition. The practical implementation of such facilities is needed to decrease its costs. Controlling circadian rhythm is one of optimizing idea to solve the problem of cost. Plant circadian rhythms are composed of a large number of genes. Expressions of these genes build complex feedback loop.The circadian rhythms have important functions in physiological processes of plants including photosynthesis and growth. Therefore precise control of circadian rhythms is able to become a key technology for plant production in artificial environments such as plant factory. When we measure the luciferase  bioluminescence to observe circadian rhythm, the sample what is small seedling or cut leaf inside petri dish is used mainly. However, the cut leaf will change brownish or die after some days. In the leaf of the lettuce, the bioluminescence damps and cannot be measured by its degradation. In addition, a cut leaf is able to grow only to some size into the petri dish. From these reasons, we cannot observe the circadian rhythm in each stage of growth and the responses to the controlled light conditions in the long term. Unfortunately, we have one more problem which LUC bioluminescence only can be measured from the genetically modified lettuce. The lettuce is modified luciferase reporter gene which fused clock gene  was used in this experiment and a firefly luciferase gene into. The genetically modified plants emit bioluminescence in proportion to the expression of CCA1. We cannot treat it for food. Therefore we paid our attention to the delayed fluorescence  of the lettuce. In this study, DF is the light which is emitted immediate after illuminated sample by light emitting diode. When photosynthesis is done, DF is emitted mainly from chlorophyll. DF reflects the physiological state in plant and can be measured in any wild type plant in real time. Therefore it can be one of important indicator of circadian rhythm. However, it is not studied the simultaneous measurement from the same individual because DF has lower bioluminescence intensity than LUC bioluminescence, these spectrums are adjacent each other and the intensity damps exponentially. Because of these reasons, spectrometry is not able to apply to measure of DF and LUC bioluminescence. Therefore, we developed the devise  which measured LUC bioluminescence and DF from lettuce, which cultivated in the state that nearer to vertical farming, at the same time in the long term.Atrazine  is a widely used triazine herbicide over the world. However, studies show that ATZ affects the human endocrine system, lymphatic system, immune system, and reproductive system, and may induce malformations and organism mutations. Although ATZ has been included in the list of endocrine disruptor compounds by the United States, Japan and the European Union and other countries, it is still registered for use in many countries due to its excellent herbicidal efficacy and low price. Therefore, the research on the safety of ATZ’s ecological environment is imminent.

Alfalfa is a kind of forage with high ecological value because of its strong adaptability and regeneration ability. In addition, its root system has nitrogen fixation ability, which can increase the content of soil organic matter and improve the physical and chemical properties of soil. Our previous research has shown that alfalfa has the potential to remediate ATZ contamination. However, excessive pesticide exposure often causes plants to produce some toxic reactions. Chlorophyll content, cell membrane permeability, and accumulation of reactive oxygen species  are commonly used evaluation indicators. Our previous study showed that the accumulation capacity of ATZ in rice leaves at different ages was different,but the mechanism of accumulation on toxic effects is still unclear. Metabolism of pesticides is one of the important ways for plants to slow down the toxic effects. The phase II metabolism  of pesticides in plants requires the consumption of certain endogenous compounds such as glutathione  and glucose, which may disrupt the balance of endogenous metabolites in plants. Cysteine S-conjugates and homoglutathione/glutathione S-conjugates are the major metabolites of ATZ in plants. Therefore, studying the regulation of ATZ on differentially expressed metabolites  and differentially expressed genes  in Cys and GSH metabolism pathways and DEGs related to the generation/elimination of reactive molecular species  in alfalfa is of great significance for the cultivation of ATZ-resistant plant varieties and the construction of transgenic plants with high remediation ability. At present, the research on the fate of organic pollutants in plants is limited to the metabolic process in plants,but the excretion of metabolites by roots is rarely reported. Root exudates refer to various substances released by plant roots into the surrounding environment. A large number of studies have reported that roots can excrete organic acids, phenolic substances, polysaccharides, enzymes and other substances in response to different rhizosphere environmental changes. It is not clear whether the metabolites of ATZ can also be excreted to the external environment and which metabolites can be excreted. The excretion of pesticide metabolites by roots is closely related to the safety of the ecological environment.Per- and polyfluoroalkyl substances  are a group of anthropogenic aliphatic fluorinated chemicals that have been used globally due to their hydrophobic and lipophobic properties. PFASs are persistent in the environment and accumulative in wildlife and humans. Perfluorooctane sulfonate  is one of the well-known PFAS in scientific literature.

It was listed in the Stockholm Convention on Persistent Organic Pollutants in 2009. PFOS was phased out from production and commerce/use in most applications in several countries. Similarly, perfluorooctanoic acid  and long-chain perfluorocarboxylic acids  are believed to be on track to be phased out. Consequently, some substitutes for PFOS/PFOA have emerged, including shorter-chain compounds, ether-PFAS,and fluorotelomers. In particular, 6:2 fluorotelomer sulfonamide alkylbetaine  is an amphoteric PFAS currently used in consumer and industrial products. It was reported in Dupont’s Capstone 1157  surfactant  and AFFFs from Angus Fire,Fire Service Plus, and National Foam. 6:2 FTAB has been detected in various environment media, such as groundwater,soil,earthworms,river water,and sediments. 6:2 FTAB was detected in the surface soil of the long-term fire training site at a high concentration of up to 66,305 ng/g dry weight. Earlier studies demonstrated that PFCA precursors could be taken up by plants from soil/solution and biotransformed to downstream metabolites. 6:2 FTSA, which is also a common PFOS alternative, ebb and flow bench could be bioaccumulated by pumpkin  and then biotransformed to stable products, such as PFHpA, PFHxA, PFPeA, PFBA, PFPrA and TFA. 10:2 fluorotelomer alcohol  could be taken up in wheat and metabolized to PFPeA, PFHxA and perfluorodecanoate  in root while PFDA and perfluoroundecanoic acid  in shoot. 6:2 FTOH  and 8:2 FTOH  could be accumulated by plants, and then transformed to intermediate metabolites and terminal products, such as fluorotelomer saturated acids,fluorotelomer unsaturated carboxylic acids  and PFCAs. Therefore, 6:2 FTAB may be transferred and degraded in plants and further contribute to human exposure through the food chain. However, studies on bioaccumulation and biotransformation of 6:2 FTAB in plants are not reported to date. The biotic and abiotic degradation of 6:2 FTAB has been investigated by several previous studies. The main photochemical degradation intermediate of 6:2 FTAB was 6:2 fluorotelomer sulfonamide,followed by 6:2 FTSA, 6:2 fluorotelomer sulfonamide alkylamine,6:2 FTOH and 6:2 FTUCA, and a large amount of PFCAs have also been observed. In addition to abiotic degradation, the biotic metabolisms of 6:2 FTAB were also investigated, showing different degradation pathways. The main metabolites of 6:2 FTAB biodegraded by strain NB4–1Y isolated from vermicompost were 5:2 fluorotelomer ketone,6:2 FTCA, 6:2 FTOH and 5:2 sFTOH, while 5:3 FTCA, 4:3 FTCA, PFHxA, PFPeA and PFBA were detected at low concentrations. Previous aerobic biodegradation test showed that biodegradation of 6:2 FTAB produced 6:2 FTOH, 6:2 FTCA, 6:2 FTUCA, 5:3 FTCA, 6:2 FTSAm and short-chain PFCAs in the presence of either active or sterilized aerobic sludge, whereas 6:2 FTSA was measured with sterilized sludge only. In addition, 6:2 FTAB could be extensively metabolized in blue mussel and turbot, with 6:2 FTAA being its major metabolite. Formation of 6:2 FTAA, 6:2 FTSAm and 6:2 FTSA indicated that 6:2 FTAB was metabolized in zebrafish. Although it has been confirmed that 6:2 FTAB could be degraded by animals and microorganisms, studies on its transformation mechanism in plants are still limited. It has been demonstrated that 6:2 FTAB had lower bioaccumulation capacity in zebrafish than that of 6:2 FTAA. Previous studies also reported that 6:2 FTAB had toxicity effects on aquatic organisms. The juvenile turbot exposed to 6:2 FTAB was identified that genes involved in the digestion and immune system were suppressed at the transcriptional level. 6:2 FTAB induced developmental toxicity in zebrafish embryos, such as cell apoptosis, oxidative stress and immunotoxicity. 6:2 FTAB and 6:2 FTAA coexposure could disrupt the adult endocrine system and impaired offspring development in adult zebrafish. 

Similar results were found by Koch et al.. Nevertheless, the K content, even in leaves of +K plants, was below the range of 5–40 mg K  indicating an adequate supply of K according to White and Karley. However, since the percentage of K in the DM decreased significantly during growth, this value may not be suitable for predicting K deficiency. Thus, a clear indication of an optimal K concentration should be defined for each growth stage and crop species. Chlorophyll, being an important pigment to absorb light energy,was not affected by K supply. In studies by Armengaud et al.  on Arabidopsis and by Veazie et al.  on Brassica rapa, the chlorophyll content was not affected by K deficit. Presumably, K was directed into the older leaves or side shoots to maintain chlorophyll production by activating specific enzymes. However, several studies revealed a decreased chlorophyll content in leaves of plants under low K supply,which was demonstrated by the decreased photosynthetic efficiency. Similarly, the effect of PEG-induced osmotic stress did not affect the chlorophyll content. However, both chlorophyll a and b content decrease because chlorophyll synthesis is inhibited by water deficit,hydroponic grow system which was obviously not severe in our study.

Generally, the chlorophyll content varies strongly in potato leaves, depending on the cultivar, time of drought stress induction  and leaf development. The decrease in chlorophyll content was caused by reactive oxygen species that are formed as a response to drought stress damaging chloroplasts. This was not demonstrated in our study, perhaps because of the short osmotic stress period. It is also likely that the stress situation occurred at a time when the plants were already fully mature, and therefore less susceptible to abiotic stress. To protect cellular structures and maintain important physiological processes, plants can accumulate low-molecular-weight compounds,which are involved in osmotic adjustment during stress conditions. These include amino acids, measured as free amino acids in leaflets in this study, before, during, and after PEG-induced osmotic stress. In both cultivars at each sampling day, K deficiency increased the free amino acid concentration. This effect might be related to the substitution of K by organic solutes. An increased concentration of organic solutes, such as amino acids, lowers the osmotic potential of plant cells, improving cell hydration and therefore cell turgor to maintain physiological and metabolic processes, which enhance plant growth under stress conditions. Interestingly, the free amino acid content of leaves during PEG induction was not affected by PEG addition in +K plants but reduced in -K+PEG plants compared to -K plants in our study.

A sufficient K supply enhanced amino acid accumulation during PEG-induced osmotic stress compared to that at a low K supply. However, the K contents in the leaves increased during the same period. In accordance with Shabala and Shabala,under K deficiency and PEG-induced osmotic stress, K ions were distributed to developing tissues and accumulated in favour of osmotic compounds since production of these compounds is metabolically more expensive for plants.To characterise the metabolic responses of the plant during stress mitigation under different K supplies, metabolite profiling was used to investigate changes in the concentrations of primary and secondary metabolites. In the metabolomic pathway for Milva, single amino acids showed a higher concentration in -K plants compared to +K plants, which was also shown by higher concentrations of free amino acids in -K leaflets. This increase was even higher when comparing -K+PEG to +K+PEG plants. In some plant species, amino acids are known to increase during drought stress or K deficiency, which was already explained in the previous section. Proline increased under PEG-induced osmotic stress in -K+PEG plants compared to +K+PEG  and -K  plants. Proline concentrations are frequently considered a metabolic stress indicator for several stress factors and its accumulation is often associated with tolerance mechanisms against abiotic stress. Many studies have confirmed that proline accumulates in plant leaves for osmotic adjustment. In this regard, K deficiency alone did not increase the concentration of proline in the sample in our study, which indicates the importance of the proline accumulation under K deficiency when at the same time leaves are exposed to osmotic stress.

Furthermore, the amino acids isoleucine, leucine, and valine accumulated, which has been shown in Arabidopsis thaliana plants exposed to drought stress and was caused by abscisic-acid regulated protein degradation. These amino acids belong to branched chain amino acids formed by pyruvate or aspartate. They are involved in abiotic stress response and act as signaling molecules further regulating gene expression. The increase in concentration of these branched chain amino acids might therefore reflect a response mechanism that is triggered under K deficiency with more pronounced effects when K deficient leaves are exposed to osmotic stress. Another branched chain amino acid is alanine, which is also formed by pyruvate and its accumulation was reported to occur under PEG-stress. Furthermore, Lea et al.  could show that asparagine and lysine accumulate in plant tissues under different stress conditions, revealing stress responses due to K deficiency and PEG, which was also shown in our study. However, the concentrations of amino acids vary strongly due to the stress effect,since individual amino acids react differently to various factors. Therefore, it is difficult to compare studies determining amino acids because of the differences in growth and environmental conditions. Responses of the mentioned free amino acids in potato leaves might provide information related to secondary metabolites of interest.

Accumulations were also observed due to -K for some organic acids involved in the TCA cycle, including α-ketoglutarate and succinate, whereas PEG led to a reduction in both K treatments. In rapeseed, Zhu et al.  showed an increase in α-ketoglutarate and succinate under low K and drought stress conditions. Contrasting results were found by Das et al.  in soybeans, where α-ketoglutarate and succinate decreased. The generally low accumulation of organic compounds and higher contents of TCA intermediates could indicate enhanced respiratory rates and energy metabolism. However, this supports the presumption that K accumulation as an osmotic adaptation against drought stress, is significantly more energy efficient than the formation of organic solutes. K is transported into young leaves via the phloem during stress to fulfill the osmotic function of other solutes. This could explain the lower sugar content in the youngest fully-developed leaves and the increased sucrose content in the -K+PEG plants on the whole plant level, at least for cultivar Milva. However, differences in metabolite profiles vary strongly depending on the type of stress, duration, severity, and cultivar.For potatoes, there is less information on K transporters and how they respond to nutrient deficiencies and abiotic stress. The analysed K transporter genes  belong to the HAK/KUP/KT family, which have different functions in K uptake and transport. In addition, they play a role in stress tolerance and osmotic potential regulation. The expression of related genes is often triggered by a low K supply, enhancing the overall K uptake. The genes of this family are expressed in different plant parts, e.g., in the leaves, roots, or stems, which indicates a connection with the primary uptake of K from the soil, as well as with cellular K homeostasis. 

The transporters studied—StPOT2, StPOT4, and StPOT12—correspond to homologous genes of Arabidopsis thaliana, where they are referred to as AtKUP2, AtKUP4, and AtKUP12, respectively. They belong to different clusters in which the various transporters can be subdivided according to their sequence homology. AtKUP2 and AtKUP4 are assigned to cluster II and described as low-affinity K transporters involved in cell expansion. The transporters of these clusters have many homologous transporters from other plant species and are described in more detail. However, AtKUP12 is assigned to cluster III and has rarely been studied. Our results showed different expressions of the three transporters depending on K supply, PEG-induced osmotic stress, and cultivar. StPOT2 and StPOT4 were more highly expressed in Milva and showed greater expression rates in -K plants at 55 dap. StPOT expression in Agria decreased at 69 dap. The expression rates of all K transporters increased again for all treatments and both cultivars during the recovery phase. Due to the fact, that the plants were already mature and had almost completed their growth cycle, the demand for K in young tissues was no longer as high as at the beginning of plant growth, which could explain the low expression levels of all the three StPOTs in Agria. Thus, Milva was not yet fully matured and was still taking up K. Accordingly, StPOT2 and StPOT4 were still active in Milva since both are related to growth processes. Compared to Agria, higher expression rates of the three StPOTs in Milva could indicate differences in the involved genes, which may vary genotypically. StPOT2 in potato and the homolog gene AtKUP2 in Arabidopsis, as well as AtKUP6 and AtKUP8, play a role in lateral root development by enhancing abscisic acid and responding to osmotic stress. In contrast, AtKUP4 is involved in growth processes by participating in auxin transport, indoor garden which in turn contributes to root hair development. These two transporters are also known to increase their expression more in roots than in leaves, which may explain the lower expression rates in our study.

Increases in the three StPOTs at 82 dap could be related to the increased water uptake of plants in the recovery phase, because more K was available, and therefore, the expression of the three StPOTs increased again. Our results showed that StPOT12 reacted similarly to StPOT2 and StPOT4, but showed higher expression rates in -K Milva plants at 55 dap and up to eight-fold higher expression at 82 dap. Therefore, protein synthesis for StPOT12 may be enhanced, participating more in K uptake compared to proteins of StPOT2 and StPOT4. Zhang et al. also showed a connection between AtKUP12 and increasing K uptake in addition to improving the salt tolerance of Arabidopsis. Therefore, StPOT12 is also involved in abiotic stress. However, the detailed physiological functions remain unclear, and further investigations are needed.Rice, a staple food for more than three billion people worlds over belongs to the genus Oryza of the family Poaceae. Consisting of two cultivated species, O. sativa and O. glaberrima, and 22 wild species, Oryza is a large genus of predominantly tropical aquatic or semi-aquatic grasses. O. sativa is grown worldwide, while O. glaberrima is mostly confined to West Africa. Domesticated since early Holocene,rice cultivation has led to cultivar diversity through phenotypic selection for desirable characters such as grain yield and grain quality. Being widely cultivated, adaptive evolution of rice cultivars over thousands of years has distributed them over wide range of environs, such as deep water to montane ecologies. Being one of the primary centers of origin, India is bestowed with wide diversity of rice landraces, wild congeners and modern cultivars.Estimated between 75000 to 100000, the number of indigenous landraces in India has shrunk over time, although a considerable portion is still conserved for a variety of reasons. In areas of conservation, farmers cherish profound knowledge of landraces such as their uses, properties and peculiarities. In Tamil Nadu, popularly called as the ‘rice granary of South India’, there were about 400 traditional landraces in vogue since olden times, which are still extant and used in households. These landraces brandish several features such as pest and disease resistance  and tolerance to flood,drought  and salt. Some others are suitable for special uses such as fodder and thatching,stamina boosters  and for medicinal uses. Understanding their importance, most of these landraces are now conserved in gene banks across the India, so that they are not destroyed due to climatic vagaries and catastrophes. The practicality of conservation of specialty rice is particularly realized during disasters such as tsunamis, floods, cyclones, etc. when conventional cultivars fail to save the situation. For instance, when the coastal Tamil Nadu was devastated by the Indian Ocean tsunami on 26th December 2004, the salt water ingression from the bay has destroyed most of the standing crops in the affected region.However, soil salinization continues to happen even without disasters along the coastal as well as inlands of India, due to poor quality of irrigation water. Globally, rising salinization limits rice production significantly in those areas, which according to an estimate, accounts for about 33% of irrigated land.

Roots were removed and the fresh weight of the individual shoot vegetation was measured. Basil is commercially important both as fresh and dry and hence both weights were measured and presented. After weighing, cut portions were dried in a Fisher Scientific Isotemp Standard Lab Oven at 60 C for 96 h. Fresh and dry weights of individual basil plants  were used to calculate the fresh and dry crop yield.Nowadays, cyber-physical systems  are drawn the attention within the industry, society and government, due to the enormous impact they have on the economy and the environment,and providing citizens and businesses with a wide range of innovative applications and services. The entry of the CPS in the industry allows high connectivity between the industrial systems and brought great advantages and a wide range of new opportunities to industries but also some questions and problems, such as those related to safety and security. Cyber security is a fundamental discipline that provides confidence in terms that CPS, their information, and supporting communications and information infrastructures are adequately safeguarded.

CPS have many unique characteristics,ebb flow including the need for real-time response and extremely high availability, predictability, and reliability, which impacts cyber security decisions. Besides, an even more critical problem is that the development of these systems has been carried out without taking into account the security aspects, nor the new risks that this automation of processes implies, which put at risk the complete industrial infrastructure,and where any security breaches to these systems could have catastrophic consequences. Taking into account the security from the earliest steps of CPS, i.e., at the design time is crucial to avoid security issues, even though it is a very challenging task. Therefore, security within industrial environments becomes a critical aspect that must be taken into account at all stages of information system development, by obtaining and defining, from early analysis and security requirements  before the system is in place. Security and safety are nonetheless two key properties of CPS  and they share the same goal, protecting CPS from failures. Security and safety refer to different but very important properties,in this paper just focus on those related to security properties for the CPS.Although security requirements are the appropriate solution for many researchers, they are difficult to obtain, analyse and manage by their subjective nature and their description in natural language. For CPS, in addition to software security requirements, we also have physical, control and communication requirements, which make the task of identifying security requirements and translating them into the design of our CPS system even more complicated. 

Therefore, having a common model  is essential, since it facilitates the definition of security requirements for CPS where any particularity of all these elements is taken into account. The high variability of the components involved in a CPS and their possible configurations make it extremely difficult to verify the correctness of the security requirements that reduce the threats and the possible risks. To manage this complexity, we propose the use of Feature Models and a set of reasoning techniques  to verify the correctness of the security requirements and diagnose misconfiguration of the features,according to a catalogue of possible correct configurations. FMs have been previously used for checking security configurations,and the diagnosis of FM configurations is a studied problem by the community. However, how it can be adapted to the specific scenario of CPS is still an open challenge  tackled in this paper. Based on the problems identified, we have developed a CARMEN framework that presents a systematic process to enable from the description of security requirements to the verification and diagnosis for CPS through variability models. CARMEN is focused on the design phase of CPS by presenting a support system for guiding the whole security requirement life-cycle:  creating a meta model which enables the definition of security requirements for CPS based on security recommendations of ENISA  and OWASP  guidelines;  load and update a variability model that encompassed the catalogue of possible correct configurations for CPS;  map both security requirements and variability model resulting in a configuration; verify the correctness of the configuration, and;  if it is not correct, the diagnosis of the configuration to modify for achieving a correct configuration according to requirements.

To explain in detail each of these steps, the paper has been organised as follows: Section 2 reviews the most relevant papers in the area. Section 3 details a case study based on Agriculture 4.0 and introduces the possible cyber-risks to which this type of systems are subject. Section 4 presents the proposed framework for the diagnosis of this type of system. Section 5 applies the proposed framework to the case study to show its applicability; and, finally, conclusions are drawn, and future work is outlined in Section 6.Feature-Oriented Domain Analysis  have become mature fields in the Software Product Line  arena in the last decades. Several are the scenarios where SPLs based on feature model analysis have been applied,and different researchers highlight the advantages of these systems since the use of Model-Driven Engineering  methodology and the SPL paradigm is becoming increasingly important. The complexity and the high variability of a CPS, and how SPL can help were analysed in Arrieta et al.  and Beek et al.,detecting the points of variability using feature model analysis. The analysis of the variability of CPS can also support the testing. Security is an understudied field in SPL area. Different approaches have been presented to manage the variability and specify security requirements from the early stages of the product line development. Similarly, other approaches addressed the idea of including the security variability into an SPL. In Fægri and Hallsteinsen,the authors established a software architecture as a reference to develop SPL, dealing with information security aspects. SPLs are currently being targeted for application in CPS, as for some researchers, no standard provides a structured co-engineering process to facilitate the communication between security engineers. 

For other researchers, information security must be a top priority when engineering C-CPS as the engineering artefacts represent assets of high value, and the research is focused on the generation of new security requirements stemming from risks introduced by CPS. On the other hand, there are approaches focused on security as a use case, such as in Arciniegas et al.  and the methodology SecPL,where is highlighted the importance of specifying the security requirements and product-line variability. These are annotated in the design model of any system. Other researchers developed a security requirements engineering framework for CPS, which is an extension of SREP. The capacity to support the high variability in the security context though Feature Models appeared in previous papers,where the authors analysed which vulnerabilities could be used to simulate attack-defence scenarios, but these simulations were not oriented towards more complex scenarios, such as cyberphysical systems.As seen in the introduction, nowadays CPS require an adequate security configuration. Therefore, some researchers are focused on the development of ontologies and security requirements. Some researchers have developed security tools based on ontologies capable of being integrated with the initial stages of the development process of critical systems. On the other hand, requirements have been analysed not only from the software side but also from the hardware perspective, including sensors and network security. Therefore they propose the development of a security requirements framework for CPS, analysing the existing ones, and concluding that currently there is no suitable requirement framework for this type of systems. Other researchers consider that CPS have unique characteristics that limit the applicability and suitability of traditional cyber security techniques and strategies, and therefore propose the development of a methodology of cyber security requirements oriented towards weapons systems. This methodology allows us to discover solutions that improve dimensions,being possible to use automated coding tools. 

Therefore, we can conclude that at present different researchers have found the need to develop requirement grammars to control the security risks associated with CPS. Moreover, derived from the complexity of the CPS, feature models have been previously used in the context of security.The earth is facing the risks of increasing soil pollution caused by heavy metals, which is particularly critical for humans as pollution concentrates on farm land where food is produced. Among the heavy metals, cadmium  is generally considered more detrimental than others in terms of toxicity and mutagenic effects on plants and humans. Cadmium has a similar structure to several essential elements, such as iron, manganese, and zinc, and it can enter the plant rely on the transporters of these elements; therefore, it can be transferred to all living organisms through the food chain, which raises concerns over risks on public health. Although some plant species, called hyper accumulators, greenhouse benches can accumulate exceptionally high amounts of Cd without obvious damage symptoms,most crops, including horticultural crops, are sensitive to Cd. The mechanisms of Cd toxicity in horticultural crops, as well as prevention of Cd accumulation in shoot tissues, have been frequently explored. Cd is absorbed from the environment into plants mainly by the roots and transported through the xylem to the plant shoots, where it can be distributed to various plant tissues. Oxidative damage is a typical symptom caused by Cd toxicity in plants. The Cd indirectly induced reactive oxygen species  can react with lipids and proteins, leading to lipid peroxidation and membrane damage. Cd accumulation also alters chloroplast ultra structure and inhibits the electron transport chain, resulting in decreased chlorophyll content and reduced photosynthetic rate. An efficient way to improve plant Cd tolerance is to minimize root-to-shoot Cd2+ transportation or lower the Cd2+ concentration in the cytoplasm.

Several metal transporters on the root epidermal cell membrane relating to Cd transportation into root cells have been reported. For example, the gene encoding a natural resistance-associated macrophage protein 5  is mainly expressed in the rice root epidermal cells, which is an important plasma membrane-localized transporter for Cd2+. When Cd enters the root cells, it can be chelated or precipitated by specific small molecules, such as metallothionein,in the plant cytoplasm and transported to the vacuole, thereby reducing Cd2+ toxicity. Furthermore, the plant uses its antioxidant defense system to protect itself from Cd-induced oxidative damage. For example, the antioxidant enzymes in plants, such as superoxide dismutase,catalase,ascorbate peroxidase,and glutathione reductase,scavenge ROS through increased activity to maintain proper cellular ROS levels under Cd stress. Due to the high mobility nature in plant tissues, Cd can replace Fe from proteins and disturb nitrogen and sulfur metabolism. Nitrogen metabolism is central to the plant response to heavy metals and plays a vital role in Cd tolerance. Cd stress in plants can disrupt amino acids metabolism, as manifested by the accumulation of several specific free amino acids that are beneficial for Cd tolerance. For example, previous study found that proline accumulated in plants under Cd stress, which was conducive to the of ROS elimination and functioned as a protein compatible solute. Furthermore, the amino acids have been confirmed to serve as signaling molecules and affect synthesis and activity of some enzymes, which play an important role in maintaining plant cell metabolism and stability. Several studies indicated that amino acids rich in carboxyl, amino, thiol, and phenolic groups are crucial for metal detoxification due to their ability to form complex metal cations to decrease their toxicity. Autophagy, a highly conserved mechanism in plant cells, targets the cellular components for degradation in the vacuole by the resident hydrolytic enzymes. This recycling system involves the degradation of cytoplasmic proteins and organelles, promoting the maintenance of nutrient remobilization and other metabolic processes. Studies have demonstrated that autophagy can be induced during abiotic stress; meanwhile, it plays an essential role in plant tolerance to various abiotic stresses, such as heat,salt,and drought. Studies on the function of autophagy-related genes  against Cd toxicity in animals are relatively clear, but lacking in plants. Previous studies provided evidence for autophagy induction in plant cells under Cd stress. However, the specific mechanisms of autophagy in the Cd tolerance of plants have yet to be explored. Here, three MdATG10-overexpressing apple lines were used to understand the involvement of autophagy in plant Cd tolerance. Results showed that MdATG10 over-expression enhanced the autophagic activity and improved the tolerance of apple plants in response to Cd stress.

However, it is important to bear in mind that even if minimising the fertiliser input had a less relevant impact on costs, it is key to preventing leaching nutrients and preserving the over-polluted aquifers in the region.Industrialization during the last centuries has led to extended areas of contamination with increased metal concentration levels. During the last three decades, eco-friendly, gentle soil remediation techniques using different plant species have been developed to address this problem. Plant characteristics such as metal tolerance, accumulation behaviour, biomass production, and root morphology determine metal extraction capacities. A number of plant species known as “hyperaccumulators” share the ability to grow on metalliferous soils and to accumulate large amounts of heavy metals in their aerial organs, to concentration levels exceeding that of normal plants >100 times without suffering phytotoxic effects. One species, Noccaea rotundifolia ssp. cepaeifolia, was found to accumulate up to 21,000 mg kg
1 Zn. Reeves and Brooks  found Zn concentrations up to 17,300 mg kg
1 in leaves of N. rotundifolia in the vicinity of a PbeZn mine in the Cave del Predile  area, Northern Italy. Reeves and Brooks  reported that this species was also able to accumulate Pb. The highest Pb concentrations were found in shoots of N. rotundifolia in Cave del Predile. The same authors reported N. rotundifolia being a Cd hyperaccumulator. 

In contrast, Koubova et al. using pot and hydroponic experiments showed that the potential of N. rotundifolia to accumulate Pb in the plant shoots biomass was negligible and did not confirm the potential Pb hyperaccumulation ability of this species.For this experiment a soil  from Arnoldstein with moderate Zn, Pb and Cd contamination and loamy texture was used as control. As this soil was moderately contaminated with Cd, we also studied Cd accumulation in shoots as well as the labile fractions and mobilisation of Cd in the rhizosphere. Part of the soil material was spiked to obtain a highly Zn, Pb and Cd contaminated soil. The desired amount of metals was dissolved in deionized water,25 liter pot then sprayed on the soil in polyethylene bags and subsequently thoroughly mixed by shaking the plastic bag. For equilibration, soils were incubated at 40 C for 3 weeks with several wetting and drying cycles using deionized water. Selected characteristics of the experimental soils are shown in Table 1. To study changes of labile metal fractions, pH and DOC concentration in the N. rotundifolia rhizosphere we conducted a rhizobox experiment using the design of Wenzel et al.  in 4 replicates. Eight seedlings were planted on top of a soileroot compartment with an opening slit at the bottom. After 6 weeks the number of plants was reduced to four, and the plant compartment was transferred on top of a rhizosphere soil compartment attached to a vertical root-only compartment that is separated from rhizosphere soil compartment by a nylon membrane  and a transparent acrylic window. After another 7 weeks, sufficient root coverage of the nylon membrane separating roots from rhizosphere soil was achieved.

Subsequently,the rhizosphere compartment was separated from the root layer. Roots adjacent to the membrane were washed in an ultrasonic bath and rinsed using bi-distilled water.The experimental soil used in this experiment was obtained from an arable field near Wiesen, Austria ; selected characteristics of this loamy soil are given in Table 2. Airdried soil was passed through a 2-mm sieve. Cation exchange capacity,organic matter content,plant available P based on the Olsen method  and plant available K using 1 M ammonium acetate  were determined. Part of the sieved soil was maintained to provide non-polluted control soil,other batches were enriched with Zn or Pb to yield nominal concentrations of 100, 500, 1000, 2000 and 3000 mg kg
1  or 250, 500, 1000 and 2000 mg kg
1  by mixing the soil with ZnO or PbO, respectively. Metal oxides were used for spiking to avoid mass flow of metals between compartments through irrigation. The near-total  Zn and Pb concentrations in Wiesen soil  were 31.9 and 4.89 mg kg-1 respectively. To meet the presumable high zinc requirement of N. rotundifolia, we also spiked the control soil to obtain 100 mg kg-1. The metal spiking procedure was carried out as described in chapter 2.2. The near total,ammonium nitrate-extractable,and calcium nitrate extractable  concentrations of Zn and Pb in the soils, soluble P,soil pH and dissolved organic carbon were determined after three weeks equilibration and are presented in Table S1. A split-root system technique was used to study the effect of localized Zn and Pb patches on the root foraging behaviour of N. rotundifolia according to a modified method of Langer et al.. Half-liter pots, which were separated into 2 equal compartments, were filled with homogeneous or heterogeneous pairs of control  or Pb- and Zn-enriched soil treatments as shown in Table 3 and Fig. S1.

The metalenriched patches in heterogeneous treatments were placed on the right-hand side of the pots. Experimental pots were equipped with a mesh permeable  for root growth but stabilizing the paired substrate patches supporting proper separation during the harvesting procedure. The free-draining pots were placed on a grid to avoid mixing of percolating water from different patches. Twelve day-old seedlings were placed individually at the contact zone of the paired soil patches. The experiments were carried out at a soil moisture of 80e85% of maximum water holding capacity in a greenhouse with a completely randomized design and 4 replications. At harvest,fresh root biomass that developed in each split substrate patch as well as shoots were harvested. Root morphological characteristics were measured on fresh root material. Fresh roots were weighed and cut into pieces. An aliquot of fresh roots from each part of the pot  was randomly selected and kept in ethanol  for root scanning; in addition, a  sub-sample was dried at 65 C for 2 days to determine the dry weight factor. Detection of root morphological characteristics in different diameter classes was done by scanning the roots using a modified Optical Scanner ; images were processed by using WinRHIZO®. To increase the contrast of the roots against the background on the scanned images, they were stained with 5% Giemza solution for 10 min at about 40 C on a heating plate. Data analyses were performed with ANOVA  in SAS software, followed by LSD and Duncan-test. The differences in root characteristics between patches were evaluated using a paired t-test.N. rotundifolia tended to produce less shoot and root dry matter in the homogeneous as compared to the heterogeneous Zn and Pb treatments. 

Comparison of root allocation patterns revealed no significant difference in the partitioning of root mass in any of the homogeneous Zn and Pb soil treatments, with approximately 50% allocation into the left and right sides of all pots. We found preferred partitioning of root mass into the low Zn and Pb halves  of heterogeneous soil treatments with a large difference of metal concentrations between low and high metal compartments. In such Zn treatments,approximately 35% of the total root mass was found in the Znenriched half patch with higher Zn concentration;similarly, in the highly heterogeneous Pb treatments  38 and 32% of total root mass respectively, allocated to the Pb-enriched half. In heterogeneous treatments with less pronounced Zn concentration differences between the high and low metal compartments,we found no difference in root dry matter allocation, however, increased root length and related larger surface area in the compartment with lower Zn concentration. The average root diameter decreased with increasing Zn concentration in soil in heterogeneous treatments except in 100/ 3000. We found no significant differences in root length and surface area between the compartments of heterogeneous Pb treatments. However, specific root area  and specific root length  were significantly higher in the Pbenriched patch in two treatments with the largest Pb concentration difference between compartments. Lead and Zn concentrations in N. rotundifolia shoots increased with increasing soil metal concentration, following a linear function for Pb but approaching a plateau in the case of Zn, with only small differences between homogeneous and heterogeneous treatments. The only considerable deviation from this pattern was found for the heterogeneous Zn treatments 100/3000 and 500/3000 where the shoot Zn concentrations in the heterogeneous treatments were clearly below the fit expected from all other data, and lower than the corresponding homogenous treatments. 

In the homogenous Zn treatments, the plant Zn contents  increased with increasing Zn supply, approaching a plateau at high soil Zn concentrations. In the heterogeneous treatments, the Zn contents follow a more irregular pattern, with lower than expected values in the treatments 100/1000 and 100/3000.The shoot Pb contents showed a linear positive response to increasing Pb concentrations in soil, with generally larger contents in the heterogeneous treatments.In heterogeneous treatments with smaller differences in Zn concentration between compartments, toxicity stress was indicated by changes in root morphology, including decreased root length and smaller root surface area in the Zn-enriched patches with higher Zn concentrations even though allocation of total root dry matter was not different. Toxicity was also indicated by decreasing average root diameter as the overall  Zn concentration in the split-pot study was increased. In contrast, spiking the moderately polluted ARN-B soil with Zn,Cd,and Pb  resulted in a ~32% increase of shoot dry matter. Overall, our findings provide evidence for high tolerance of N. rotundifolia to Zn in hydroponic solution and even on soil from its natural habitat spiked with a metal cocktail, whereas this species appeared to be more sensitive to Zn-only spikes in an initially low-metal agricultural soil. Taking all evidence together we classify this species as highly tolerant Zn accumulator plant. N. rotundifolia exhibits similar tolerance to Zn exposure as N. caerulescens, raspberry cultivation pot albeit at lower levels of Zn accumulation in shoots. In the hydroponic Pb dose-response experiment, N. rotundifolia accumulated enormous Pb concentrations in its roots, with almost 81.8 g kg
1 at 1000 mM Pb in solution. However, only a small proportion of Pb was transferred to shoots, with ~1250 mg kg
1 in the 1000 mM Pb treatment.Only at this largest concentration the commonly accepted hyperaccumulator threshold of Pb was exceeded. Apart from the high Pb concentrations  in the soils of the split-pot experiment, Pb concentrations in shoots did not exceed 100 mg kg-1 thus remaining one order of magnitude below the hyperaccumulation threshold.Even in the spiked soil the Pb shoot concentrations in the rhizobox experiment did not exceed 86 mg kg-1. This is in contrast to previous reports of Pb hyperaccumulation by N. rotundifolia, with Pb shoot concentrations up to 8200 mg kg-1 in field-collected specimen from the Southern Alps in adjacent regions of Italy and Austria. 

In all experiments of our study, the shoot: root concentration quotient of Pb was clearly <1, decreasing to values near 0.01 in the highest Pb treatments of the hydroponic study. Similarly, the bioconcentration factor for Pb remained clearly below 1 in all experimental setups. N. rotundifolia responded to Pb with decreased root and shoot dry matter production, starting from the lowest level of exposure. On the other hand, we found increased dry matter production upon spiking a moderately metal-polluted soil from the plant’s native environment with a cocktail containing Cd, Zn and Pb, resulting in a soil concentration of 1650 mg Pb kg-1. As for Zn, the root biomass of N. rotundifolia was evenly distributed in all homogenous and heterogeneous treatments unless the concentration difference between the compartments was very high. We found no significant differences in root surface area and root length between the compartments of heterogeneous Pb treatments. However, specific root surface area  and specific root length  were significantly higher in the Pb-enriched patch of the two treatments with the largest soil Pb concentration difference between compartments. Taking together all evidence obtained in our study,we challenge earlier reports on Pb hyperaccumulation properties of field-collected N. rotundifolia specimen from the same site. Our findings support the doubts regarding the identification of hyperaccumulation solely based on field-collected specimen related to potentially ineffective washing procedures prior to analysis. In that case aerial contamination from emissions or soil dust derived in the vicinity of the collected plant specimen cannot be excluded and may bias the results towards meeting hyperaccumulation thresholds.

The article analyzed the potential of increasing fodder productivity, seed quality, and control and the potential of fodder production in different aspects of open fields like using barren lands from salinity or water scarcity. Significant industrial development has been noticed in recent years for high-tech controlled environment fodder production, especially in the United States, Europe, and Australia. Many start-up industries evolved in the market with advanced technologies for large-scale hydroponic fodder production with artificial lighting. However, minimal research activities have been reported in terms of technological development like environmental control, optimization in energy and water use, automation, and control. There is an information gap in the potential of CEFP and their challenges from engineering aspects, especially the energy use in HVAC and lighting systems. The critical analysis of thermal environmental control techniques and challenges for CEFP is essential for researchers, industry, and producers. A comprehensive review would be beneficial for understanding the prospects and limitations of CEFP for various stakeholders.

Livestock units are expected to increase up to 50%, and arable land per capita will decrease by approximately 23% in 2050 compared with the number in 2012.CEFP would increase as the arable land demand for human food production with the increased world population. A critical analysis of thermal environment control for CEFP would benefit various stakeholders from academia to industry. Therefore, this article presents a comprehensive analysis of multiple aspects of CEFP for livestock production. Section 2 presents hydroponic growing methods and their application for CEFP, and different facility types are analyzed in Section 3. Section 4 includes the analysis of previous studies on nutritional aspects, including the pros and cons for livestock productivity. Indoor environmental requirements and techniques for sustainable barley fodder system production are presented in Section 5, and potential option and control techniques are presented in Section 6. Finally, Section 7 includes a comprehensive analysis of the prospect, challenges, and research needs to achieve sustainability goals for the CEFP. Hydroponics is a method of growing plants using nutrient solutions or water without soil. Different types of leafy vegetables and fodder could be produced using hydroponic systems. The growing system could be open systems, where the nutrient solution or water is not recycled, and closed systems recycle excess water from growing systems. The open hydroponic systems are not practically feasible due to wastage of water and nutrients.

An experiment study showed that using macro and micro-nutrients with water does not significantly affect the yield of wheat fodder grown hydroponically for seven days. So, hydroponic fodder grown in CE comes without fertilizers and chemicals, making it a sustainable solution for livestock production. Based on the solution/water feeding methods, six different hydroponic techniques are available for growing plants, such as nutrient film system , deep water culture system , aeroponics system , ebb and flow system , wick system , and drip hydroponic system. Fig. 3 describes the basic working principles for various watering methods for hydroponic production and their associated advantages and disadvantages. NFS, EFS, and DWCS are commonly used for leafy green production in CEA applications. The aeroponic system is the advanced form of the hydroponic system, which could be challenging for CEFP. Table 1 shows critical influencing indicators to develop a decision matrix for watering technologies in hydroponic production. The information presented in Table 1 is generated from Verner et al.. WS is relatively simple, with no energy demand components as no motor is required for water movement, but not suitable for large-scale production. DWCS system is also simple and less energy-intensive, but a large volume of water is needed for operation and is prone to water-borne diseases. In general, the hydroponic fodder production technique is slightly different from the techniques used for fruit and vegetable production. The standard technique for fodder production is spraying solution or water at certain intervals and draining excess water to the tank for recycling . However, the performance of these techniques for fodder production has not been extensively studied.

In general, the concept of the NFS is most promising for draining the water in a hydroponic fodder production system. The slope of the growing bed is a critical parameter in the NFS that needs to be optimized for better performance. Growing trays in NFS are positioned at some angle or slope to facilitate a nutrient solution to drain into the nutrient solution reservoir and recirculate. NFS with a 1.5% slope was found ideal for lettuce production, and a relatively steeper slope was found beneficial for tomato productivity. The impact of growing trays slope on the productivity of green wheat fodder in the NFS system was evaluated with two different light sources . The study reported that the highest yield of wheat fodder after seven days of cultivation could be achieved with growing trays sloped at 6.5%. Matos et al. designed a hydroponic fodder production system based on the concept of the DWCS, but the study did not evaluate the performance compared with other standard techniques. Fig. 5 shows a complete CEFP unit with NFT system with 8% slope and other cirtical components for automated production system. To our best knowledge, no research has been conducted to assess the performances of the various techniques for supplying nutrient/water for fodder production. Also, the water-saving potential of an innovative approach for CEFP needs to be investigated to minimize the possibility of molds and waterborne disease contamination with fodder. Greenhouses could be used for fodder production to minimize energy-intensive artificial lighting. FAO recently supported a project for hydrophobic fodder production and established 79 simple greenhouses structures across seven regions in Namibia. The project began in 2020, benefited around 3,350 households, and saved their livestock from dying. Different low-tech greenhouse structures are mainly used for fodder production based on local conditions and resources. A study reported that a high-tech greenhouse requires about 8-15 kWh of electricity to produce 600 kg of hydroponic maize fodder daily, which could be minimized using a low-tech net house. S´ anchez del Castillo et al. evaluated the effect of different densities for growing wheat and barley in a low-tech poly-covered greenhouse in Mexico.

The low-cost hydroponic systems made of locally available materials are common in developing countries. In Malawi, hydroponic fodder has been produced in a simple poly-covered greenhouse with wooden frame shelving for trays. The major challenge in low-cost fodder production systems is controlling or adjusting the temperature, humidity, and air circulation, especially during the dry, hot summer months. The yield and type of fodder grown in these low-tech facilities are highly dependent upon the season and climatic condition of the locality/region. Modular farms are flexible and self-contained systems that allow growing fodders or vegetables without soil or sunlight. Hydroponic fodder could be grown in stackable vertical trays in warehouse-like structures or shipping containers with the help of artificial lighting. Grov Technologies in Utah, USA, has designed different vertical growing units for warehouse-type facilities to grow with advanced technologies like the Internet of Things , cloud, robotics, and machine learning for lighting and spectrum management to maximize potential yield. They claimed that their olympus tower could produce 2,300 to 2,700 kg of sprouted wheat or barley grass per day using less than five percent of water and replacing 35 to 50 acres of land compared to traditional farming. Similarly, two young farmers set up a warehouse hydroponic facility to produce high-quality green fodder for livestock in the Canary Islands in Spain. An 80 m2 facility could produce 1,000 kg of barley per day, providing a continuous supply of green fodder for 300 goats. The report indicates that the system could save 90% more water than traditional methods. Other industries have also been marketing the stackable vertical farming system to grow fodder in indoor spaces like warehouse-type structures or retrofitted abandoned buildings to grow livestock fodder. Agritom based in Australia, claimed that their custom type machine could produce from 100 kg to 1,200 kg of fodder per day, with a footprint ranging between 4.5-29.0 m2. HydroGreen is a local chain ag-tech company founded by farmers in South Dakota in the USA, manufacturing a fully automated vertical growing system that produces high-quality nutritional green fodder. They reported that about 2,700 square foot buildings could replace about 600 acres of land and produce 5.0 tons of fodder daily using a fraction of the water used in traditional crop production.

Fodder Tech, a company based in Utah, manufactures and markets different sizes and modular fodder production systems. The stackable vertical farming system could produce 9,000 kg of fresh fodder per day. A fully automated shipping container type system is becoming popular for growing fodder under extreme climates. Many companies are marketing the shipping containers type systems with a production capacity range of 50-2,500 kg per day, depending on the size of units. Agritom is currently marketing nine different sizes of the container system with LED lighting systems having rated production capacity per day between 50 kg to 2,250 kg. They reported that a 30 m2 system could produce 1,000 kg of green fodder per day compared with 1.0 hectares of land required in the traditional farming system. Fodder Tech is marketing various sizes of shipping containers with a capacity range from 50 kg to 900 kg per day. Table 2 summarizes some current industry leaderships for manufacturing and marking the CEFP systems. It is often said that the need for green fodder for livestock is as important as the need for good nutritious food for humans. Green fodder is always considered an inevitable,hydroponic barley fodder continuous, and economical source of nutrients for livestock from normal production perspectives. Compared with other available dry roughages, fodder is a natural, highly palatable, and digestible feed enriched with micro-nutrients resulting in improved nutrient digestibility, health, and performance of animals. Therefore, ensuring continuous and secured fodder supply is considered a major driver of sustainable and profitable livestock production. Hydroponics is a successful growing technique that offers a constant supply of green fodder all year round, even in all sorts of worse climatic conditions for sustainable livestock production. These plant materials and fodders are abundant in protein and energy, easily digestible, and utilized by most animals. It is reported that sprouted barley produced in hydroponic systems contained higher fiber, protein, and minerals than the barley grain. The nutritive value of animal feed could be analyzed in terms of dry matter , crude protein , crude fiber , ether extract , ash content , neutral detergent fiber , and acid detergent fiber . Thadchanamoorthy et al. showed that at 10th day after planting, the nutritive value of sprouted maize were greater compared to maize grain.Usually, when compared with respective grain/seed, hydroponic fodder has fewer contents of organic matter and non-fibrous carbohydrates,whereas increased contents of CP, NDF, ADF, and Ca.

This shift of nutrients is good for dairy animals from an animal nutrition perspective. Moreover, another study also revealed that hydroponic wheat fodder increased the DM, CP, EE, CF, K, and Na contents by 5.0%, 44.0%, 132.5%, 176.9%, 150%, and 320%, respectively, compared with conventional wheat fodder. Another study evaluated the yield and nutritional value of three barley cultivars that were harvested on the 6th, 8th, 10th, and 12th days. The study reported that the DM content of barley grain was 93.6% on the 6th day and decreased to 91.1% on the 12th day, whereas CP remained the highest on the 12th day of harvesting. Also, hydroponically produced green fodder exhibits various enzyme activities that break down complex proteins into albumin, globulin, and amino acids, resulting in higher protein quality . Studies also revealed that germination accelerated amylase and lipase activity in hydroponic fodder, increasing sugar and fatty acid content. The fatty acid concentrations in hydroponic fodder, particularly ω-3, ω-6, and stearic acid, increased linearly with the growing period. The sprouting process can significantly increase vitamins A, E, and β-carotene content compared to their grain. One study showed a 700% increase in vitamin E in fodder from grain; however, it is suggested to exercise caution about these numbers—while these numbers indicate a significant increase, based on dairy cow intake requirements, they may not be high from a biological perspective.