Horticulture

Specifically, water stress resulted in the lowest increase in leaf area development , and leaf size tended to decrease with decreasing water supply. A study found that leaf area was strongly negatively correlated with leaf water loss,suggesting that bigger leaves of P. sibirica and U. pumila in 4 and 8 L h−1 irrigation levels may be less prone to water loss via evapotranspiration. The efficient use of irrigation and fertilizer has recently gained much attention in reforestation efforts in arid regions because of the highly variable or limited rainfall events. In this study, we revealed that the interaction of 4 and 8 L h−1 with NPK or COMP positively increased LB of all species. This can be attributed to enhanced cell divisionand physiological activities under water-sufficient or high turgor pressure conditions and improved nutrient availability.

Our result is consistent with that of some water and fertilizer experiments conducted in drylands . Similarly, Zhang and Xi observed that the aboveground plant biomass increased when precipitation increased and decreased when precipitation fluctuated significantly. A significant increase in aboveground biomass and leaf area was also detected when the plants were supplied with nitrate, and such a result was associated with the effects of nitrate on cell turgor pressure . Thus, the current result suggests that sustainable reforestation in arid and semiarid regions in Mongolia can be achieved with the use of a combination of the appropriate amount of water and fertilizer. This is because excess water and application of both organic and inorganic fertilizers can exacerbate land degradation and environmental damage in arid and semiarid regions. Contrary to our expectation, CONT and a low amount of irrigation have generally shown to have a higher total chlorophyll content compared with a high amount of irrigation with/without NPK or COMP, particularly in 2019 for both species.

The result of the present study agrees with the findings of Hassanzadeh et al. , who reported that irrigating the plots under flooding conditions led to a decrease in chlorophyll content and senescence, whereas drought stress increased chlorophyll content. Our result is attributable to the effects of moisture on photochemical activity and chlorophyll synthesis in leaves. Conditions such as excess water and nutrient availability may have hindered the chlorophyll synthesis of irrigated plants, particularly those grown in 4 or 8 L h−1 with NPK and compost. Several studies explained that low levels of chlorophyll in leaves might be poorly related to water conditions in the field because of interacting effects of the other environmental factors, such as soil characteristics, light, and air temperature . A change in the amount of far-red radiation and light reflectance of leaves was also cited as one of the reasons for the change in chlorophyll content with increasing soil moisture .

A study by Hamblin et al. also mentioned that the reduction in leaf chlorophyll content can reduce the heat load, thereby reducing water requirement to cool leaves. Nitrogen is an essential part of the chlorophyll molecule; hence, the lack of it in the mineral nutrient supply may significantly affect chlorophyll synthesis in plants. Here we revealed that adding NPK or compost to a higher amount of irrigation significantly decreased the chlorophyll content compared with CONT in all species, implying that some factors such as mineralization, leaching, and volatilization may have come into the picture. Because of the high amount of irrigation, the applied fertilizer may have been leached out, leading to N deficiency in plants. Another possible reason is that the high amount of irrigation may have facilitated the mineralization of the applied fertilizer in the soil, leading to a luxury consumption of N by plants. Such a luxury consumption produced excess N that may not be metabolized into functional or structural compounds necessary for chlorophyll synthesis. One study, however, reported that the stress-induced loss of chlorophyll was not linked to a lack of nitrogen .

This is probably because of the effect of water stress on nitrogen mineralization and uptake. Further, the significant reduction in leaf chlorophyll content may be a consequence of increasing the LA, SLA, and LB of the plants grown in a higher amount of irrigation with NPK or compost. The scientific name of the oriental persimmon is Diospyros kaki, and it is classified as a deciduous tree belonging to the family Ebenaceae of the genus Diospyros. The persimmon originates from northern China and is said to have been introduced to Japan during the Nara period, which took place over the years 710–794. The astringency of the peels of persimmon is caused by tannin, which is a condensation product of epigallocatechin,epicatechin, and their galloyl compounds. When persimmons ripen, acetaldehyde is generated within the flesh of the fruit and forms cross-links with the water-soluble tannin to form polymers, making the tannin insoluble and thus reducing the persimmon’s astringency .

Australia is the largest producer, with 47.1% of the global production, while Europe is second according to FAOSTAT . In Europe L. angustifolius L. and L. luteus L. are the predominant cultivated species in the north and countries with more than 10,000 ha of lupins are Poland, the Russian Federation, Germany, Belarus, and Ukraine. In the south, where L. albus L. is predominant, Italy , France , and Spain are the main lupin-producing countries . Modern breeding efforts to improve white lupin agronomic characteristics are very recent . Thus, there is still significant variability even among commercial germplasm for the most essential breeding targets, namely, the seed’s nutritional value and the toxic, bitter secondary metabolites QAs . The total alkaloid content in white lupin varies from 0.02 to 12.73% of the seed’s dry weight. Cultivars possessing the pauper gene contain 0.02–0.05% alkaloids of the seed dry weight . The recently published white lupin pangenome study demonstrated that pauper locus has a key role in the species domestication and breeding .

Other important agronomic characters of white lupin, which attracted the breeders’ attention, are vernalization insensitivity , anthracnose resistance , yield stability , and abiotic-stress acclimation . White lupin’s global commercial potential has incited the breeding interest to focus not only in yield boost, but also in expanding its cultivation to agroclimatic regions, other than the Mediterranean basin, as extreme climate-change-related phenomena push the cultivation of some crops northwards . On top of that, restricted precipitation levels during spring and frequent dry spells, throughout the Mediterranean basin, as a consequence of climate change , have a detrimental impact on pollen fertility , pollinator-flower interactions , pod filling, and seed development, resulting in premature harvesting and yield losses.Anthracnose is a global fungal disease, responsible for devastating epidemics, characterized by signifificant yield losses . Temperatures over 10 ◦C and humid weather promote conidia germination, with 25 ◦C being optimal for fungal growth; whereas dry summer conditions are favorable for the preservation of inoculum on unharvested plant tissues .

Colletotrichum lupini, is mostly identified as the responsible pathogen for lupin anthracnose. Nonetheless, it has been reported in several other crops such as olive . The pathogen emerges as an alarming polyphagous phytopathogenic strain for the Mediterranean agriculture. White lupin breeding has been directed to the creation of elite anthracnose resistant cultivars, employing map construction, genomic screening, phenotyping tools, fifield experimentation, and generation of molecular markers, to detect anthracnose resistant accessions . Thus far, Ethiopian landraces have been extensively studied, revealing a highly diverse germplasm and embodying unique loci that confer resistance to anthracnose . Successful breeding significantly depends on the extent of the available genetic resourcesPhenotypic and molecular markers have already been used in few studies, to estimate the genetic diversity between wild and breeding white lupin germplasm, and to enable incorporation of potentially valuable alleles from distantly related wild accessions tothe genetic pool of elite cultivars .

Additionally, molecular markers are continuously developed, for the effective selection of germplasm with desired traits . Furthermore, genomic resources are now available in white lupin and their use will greatly advance our understanding of the species diversity. In such an effort, very recently genome sequences of 39 accessions were used to establish a white lupin pangenome that can be used as resource to identify genes linked to important agronomic traits and analyze genetic variability. Although such progress will inevitably lead to development of more sophisticated tools to explore genetic variation in white lupin genetic resources, up to now SSR markers have been proved integral tools to investigate species diversity. The Balkan Peninsula represents a yet untapped germplasm diversity center for white lupin, concealing potentially valuable loci in landraces and natural populations that could promote adaptability to climate-change-relevant extreme conditions . In this study we applied available SSR molecular markers linked to agronomically important traits and morphological seed characteristics to explore the genetic diversity of white lupin Greek landraces and compare it with that observed in commercial varieties and breeding lines.

Results of the study may facilitate marker assisted breeding in white lupin and enable identification and introgression of valuable alleles into new elite cultivars. All seed morphological characters’ measurements were statistically analyzed and a summary of the statistics is shown in Table 1. The Multivariate Analysis of Variance indicated that all 45 accessions are distinguished from one another, when regarding their seed morphology, with statistical significance . A Pearson’s correlation matrix revealed strong correlation between seed area with TSW, perimeter and width and between mean Gray Value with maximum and median Gray Value , suggesting, that a single character measurement is sufficient to represent highly correlated characters.

We previously showed that this compound has a remarkable antibacterial activity at low concentrations: 0.24 µg/mL against Staphylococcus aureus and 3.9 µg/mL against Escherichia coli . As such, we have strong reasons to consider that BrCl-flav has a good potential for the development of new antimicrobial agents. Therefore, further studies using four clinical Candida isolates were employed to investigate BrCl-flav antifungal properties and mechanism of action. A potent antifungal effect was evidenced for BrCl-flav against all Candida strains tested in vitro using the determination of minimum inhibitory concentration. The method allowed us to assess the lowest concentration of BrCl-flflav which inhibited the growth of the tested fungal strains—15.62 µg/mL.

When compared with the reference drug fluconazole, a considerable higher antifungal activity was recorded against fluconazole resistant C. albicans, C. krusei and C. glabrata isolates. Compared to most of the reported natural and synthetic flflavonoids, our compound displayed a stronger antifungal activity, being up to 28-fold more active against Candida spp.. We must emphasize that BrCl-flav exhibited an antifungal activity comparable to some chalcone, flavones and flavanones derivatives considered to be the most potent synthetic flavonoids against Candida reported so far. The fungistatic effect was dose-dependent, increasing concentrations of BrCl-flflav progressively inhibited the fungal growth of all tested Candida isolates.

The cells incubated with 7.81 µg/mL BrCl-flflav showed no significant growth inhibition compared with control. On the other hand, a signifificant growth delay represented by prolonged lag phases occurred when Candida spp. cells were incubated in the presence of BrCl-flav at 15.2 µg/mL, corresponding to MIC. We must point out that no turbidity was recorded by spectrophotometric measurements for all Candida cells exposed to 31.25 µg/mL within the time span of the experiments , denoting a strong fungicidal activity. A time-kill kinetics assay was employed to determine the fungistatic or fungicidal activity of BrCl-flav over time. The analysis confirmed also the important antifungal activity of BrCl-flav against all Candida spp. after exposure to concentrations equivalent to MIC and 2 × MIC . One exception occurred for C. albicans strain—a fungistatic effect was recorded by the growth experiments up to 24 h, while time kill studies revealed a fungicidal effect at 24 h.

We must emphasize that no viable cells were detected starting with 12 h after BrCl-flav exposure at 31.25 µg/mL , suggesting an important fungicidal potential. The fact that this activity has been recorded against fluconazole-resistant Candida strains makes BrCl-flav a more interesting compound for practical applications. Our conclusion is supported by a comparative literature survey which revealed that BrCl-flflav has higher fungicidal activity compared to many natural flavonoids.Also, the recorded activity was higher or comparablewith other synthetic flavonoids such as different chalcone, 1,3-thiazole and 2-hydrazinyl- 1,3-thiazole derivatives.We must emphasize that BrCl-flav acted as a more potent fungicidal compared with fluconazole, considered to be a gold standard of antifungal agents . Sorbitol binding affinity assay was used to investigate the interference of BrCl-flav with the Candida cell wall. Sorbitol is an osmotic protector which can support cell growth when the fungal wall is targeted by antifungal agents. In the absence of sorbitol, the fungal growth is inhibited due to the disruption of the cell wall. The effect is detected by an increase of the MIC value in the presence of sorbitol compared to the MIC value determined in medium without sorbitol.In our study, MIC values of BrCl-flav did not change in the presence of sorbitol, suggesting that the tested synthetic flavonoid does not target the cell wall. Therefore, other potential cellular targets were investigated. Penetration of PI into dead or injured C. albicans cells was evidenced using fluorescence microscopy. PI is a cell membrane-selective permeable dye that can only pass through damaged or permeabilized cell membranes, binding to DNA and exhibiting characteristic red fluorescence.

Our results revealed a gradual increase of the fluorescent cells number with the increasing concentration of the tested antifungal. After 24 h all cells exposed to BrCl-flav at a concentration equivalent to 5 × MIC were fluorescent, suggesting that the tested antifungal significantly damaged the fungal cell membrane integrity. Usually, damages to the cell membrane are related to cell lysis. SEM image analysis showed severe alteration of the cell morphology, with collapsed cells, wrinkled surfaces, along with cellular debris resulting from the disintegration of the BrCl-flav treated cells. These morphological changes are most likely caused by cell lysis.

The global recognition of the importance of this approach in also reflected in the G20 Rome Declaration from the recent Global Health Summit, held in May 2021 . The locution of One Health is undoubtedly not novel to parasitologists, who, by vocation, study infections and their causative agents and hosts, at the interface with human and veterinary medicine. With special regards to parasitic conditions, Africa harbours a plethora of them that require to be addressed according to the One Health approach, due to the dependence of parasites and their potential vectors or intermediate hosts on numerous environmental factors , habitat conditions such as temperature, humidity, availability and type of waters , etc.. For instance, malaria, the parasitic disease par excellence of the African continent, provides a compelling example of a condition that needs to be tackled through One Health efforts, due to the zoophilic behaviour of several competent mosquito vectors .

This is the approach taken by recent investigations aiming at treating cattle and other livestock with ivermectin or macrocyclic lactone-based “endectocides”4 in order to reduce the fitness of competent malaria vectors feeding on them . Similarly, the application of pyrethroid-based insecticides or arthropocides to cattle not only aims to control livestock-specific ectoparasites but also to reduce populations of zoophilic mosquitoes responsible for malaria transmission . These methods could be considered as complementary tools that could help reduce malaria incidence in a given area, although alone they may not suffice to eradicate the disease. It is nonetheless essential that control campaigns consider all hosts on which competent mosquitoes feed and the outdoor component of malaria transmission. Other major parasitoses of the African continent are ascribed in the group of the so-called Neglected Tropical Diseases , of which Africa bears ~40% of the world’s burden . These are typical diseases of poverty, highly endemic in rural areas, not coincidentally where hygiene conditions and water sanitation are poor and where tight cohabitation between humans and animals occur .

Out of the 20 NTDs recognised by the WHO, 19 occur in Africa, with 11 of them being of parasitological aetiology. Of these, at least seven include zoonotic agents . Although not involving a parasitic causative agent, NTDs like dengue and chikungunya still require parasitic arthropods as vectors , further highlighting the relevance of parasitological and entomological expertise in the study, management and control of most NTDs in Africa and elsewhere .Undoubtedly noteworthy in the area of One Health are also the so-called Neglected Zoonotic Diseases , that are deemed as “neglected” due to under-reporting on their occurrence, leading to an underestimation of their relevance to policy-makers and donors . The NZDs comprise a subgroup of NTDs , all of which except rabies are of parasitic aetiology. Currently, rabies, echinococcosis, foodborne trematodiases and taeniasis/cysticercosis are considered as priority NZDs by the WHO Department of Control of NTDs ; the fact that three of them are parasitic infections further highlights the topicality and heavy burden of parasitesin the realm of zoonoses. In addition, zoonotic causes of non-malarial febrile illnesses such as anthrax, brucellosis and leptospirosis are also recognised by the WHO to be of growing importance and are therefore monitored accordingly . The control of NTDs is a fifirm component of the UN 2030 Agenda for Sustainable Development, as reflflected in its Sustainable Development Goal target 3.3 aiming, by 2030, to “end the epidemics of AIDS, tuberculosis, malaria and NTDs ” .

In the past decade, some substantial progress was made in these regards, with 31 countries having succeeded in eliminating at least one NTD, eight of them being in Africa. However, despite these results, many of the targets set by the WHO in the 2020 roadmap were not met, in Africa and other endemic regions . In particular, the overall control of NTDs was negatively affected by the disruptions caused by the COVID-19 pandemic in the year 2020, with major hindrances being recorded in the delivery of health services . Accordingly, a new NTD roadmap was defined for the period 2021–2030, identifying critical gaps and actions required in order to prevent, control, eliminate or eradicate the 20 target diseases and disease groups . Importantly, the new agenda fully acknowledges the value of adopting an integrated One Health strategy for NTDs, promoting stronger multisectoral collaborations among agriculture, livestock, wildlife, environment, food safety, health and other ministries . Such a strategic development derives from the consideration that all zoonotic NTDs, in order to be fully controlled in human populations, need to be managed appropriately and possibly synergistically in animal hosts and/or reservoirs. Notably, tackling NTDs involving livestock species in their epidemiology , can provide dual benefifits in terms of human and economic development, by reducing risks of zoonotic infections, on one hand, and improving communities’ livelihood, through better animal health and productivity, on the other .

Previous documents show that increased photosynthetic capacity due to Mo supply contributes to the accumulation of carbohydrates, such as fructose and glucose.We observed that lipids, fibers, and saponins were significantly increased in CA1. Flavonoids were increased reasonably in CA3.Different impacts of Mo were observed in different species/cultivars, which might be due to different genetic backgrounds and the variable uptake of Mo.Phenolics play essential roles in plant development; these aromatic benzene ring compounds with one or more hydroxyl groups are produced by plants mainly for protection against stress .

In our study, the Mo priming of Canavalia seeds significantly increased the phenolic content of CA3 sprouts; a non-significant increase was found in CA2 and, surprisingly, a slight decrease was noticed in CA1. This might be due to differences in endogenous molecular pathways of different species. This link to the inherent levels of mechanisms may also lead to differences in the enhancing patterns of the individual phenolic compounds after Mo treatment, which we observed in our study. A similar trend was observed in DAHPS, the first enzyme of the shikimate pathway, which converts PEP and E4-P into 3-dehydroquaianate. Further, to assess the impact of Mo seed priming and enhanced phenolic production on the pharmacological properties of plants, we performed antioxidant and antidiabetic assays. FRAP, ABTS, and DPPH assays were used to evaluate the antioxidant capacity of species samples spectrophotometrically.

An increase in antioxidant potential was observed after Mo treatment in all species. In the FRAP assay, the increase was significant in both CA1 and CA3. CA3 also expressed a significant changein antioxidant activity, measured via ABTS assay. This correlates to the above findings that more impacts of Mo on synthetic pathways were observed in CA3. Antioxidant activity has recently become a target for product development in the pharmaceutical and cosmetics industries .Canavalia species are of medicinal importance due to their potential antioxidant properties. In a study, Canavalia gladiata extract, at the concentration of 2 mg/mL, showed an antioxidant effect comparable to that of ascorbic acid of the control group . Plant growth and antioxidant capacity are greatly dependent upon N availability. Higher N improves the stress tolerance of plants via enhancement of the antioxidant ability and inhibition of lipid peroxidation. Mo primarily improves the nitrogen fixation to the plant and increases its antioxidant potential, which we observed in our study. This also might be the reason for the enhanced antidiabetic potential of Canavalia species assessed by GI, α-amylase inhibition activity, and α-glucosidase inhibition activity.

Terpenoids and flavonoids of Canavalia gladiata are reported to play a role in lowering glucose levels and possessing antioxidant potential.The Mo-mediated enhanced concentrations of terpenoids and flavonoids might have led to the increased antioxidant and antidiabetic activities of Canavalia sprouts in our study. For sample preparation, we used an ETA 0067 grinder with grinding stones, VIPO mini grinder, followed by homogenization by Vibrom S2 , and a cryogenic grinder accompanied by liquid nitrogen. Supercritical fluid extraction using SE-1 extractor and a steam distillatory apparatus according to CSN 58 0110 and CSN 6571 were successively applied for extraction and subsequent determination of the total content of Canavalia oils. Approximately 500 mg of each sample was transferred into an extraction column for SFE extraction. The extraction was performed at 40 MPa for 60 min, and extractor and restrictor temperatures were 80 and 120 ◦C, respectively. The extract was further trapped into a hexane layer inside a trapping vessel.The determination of phenolics and their precursor metabolites was carried out using an ultra-performance liquid chromatography system coupled with a quadrupole mass spectrometer provided with an ESI source according to Wang et al.’s method.

Phenolic and flavonoid levels were identified by comparing the standard mixture of different phenols and flavonoids to the relative retention time. The concentration of each compound was calculated using the peak area of the corresponding standard. In addition, deoxy-d-arabino 201 heptulosonate-7-phosphate synthase activity was analyzed according to Wang et al., . This enzyme catalyzes the reactions in cinnamic and shikimic acid pathways that are involved in phenylpropanoid biogenesis and therefore in the biosynthesis of coumarins. Samples were first homogenized in 3 mL 50 mM Tris-HCL buffer . The assay mixture contained 0.1 mM erythrose-4-phosphate, 0.2 mM phosphoenolpyruvate, and 0.1 mM MnSO4/0.1 mM CoCl2. In total, the reaction was initiated by enzyme addition and terminated by 25% trichloroacetic acid addition.

The potential yield of bioethanol is apparently higher in cassava than for any other plant species, including the traditional bioethanol source crops such as maize, sweet sorghum and sugarcane. However, the gap between the potential experimental yields of cassava and the actual yields on farmers’ fields is more than fivefold . With the exception of India, current farmers’ yields as low as 6 – 8 t/ha exists in Africa and as high as 13 – 18 t/ha occurs in some Asian and Latin American countries. These low yields are normally attained with local, traditional varieties grown on marginal soils without the application of purchased agrochemicals.

The expected higher demands in developing countries for cassava products as food, feed, and industrial uses in the face of climate changes would call for the removal of the many socioeconomic constraints on cassava production, uses and marketing. Moreover, since the cassava plant has inherently high leaf photosynthetic capacity in current air and at high temperature coupled with high solar irradiances , also , and responds positively to elevated CO2, possible future expansion in cassava cultivation may enhance atmospheric carbon sequestration, and hence helps mitigating adverse effects of globally warming climate . Under the predicted CO2 rises in this century , cassava may be one of the few tropical food crops that can adapt to this climatic changes by shifting upward its optimum temperature for photosynthesis, growth and production.

Most crops increase their WUE in elevated CO2 environments, particularly under water deficits,due to both higher carbon uptake and lower stomatal conductance to gas diffusion that lead to less transpiration water losses. Cassava is equipped with a tight stomatal control mechanism over gas exchanges, which is more sensitive to changes in air humidity and soil water status than other crops , also , making it highly efficient in water use . As most cassava production by smallholders occurs in marginal lands with low levels of soil fertility , cassava breeding strategy at CIAT focused on selection for adaptation to farmer’s field conditions . Cassava soil-and-plant nutrition management section , and later cassava physiology section , oriented their research objects toward characterization of CIAT cassava germplasm in response to infertile, low-P, acidic soils in the South American tropics.

From 1982 to 1996, more than 1800 accessions, including land races, common varieties and elite CIAT breeding lines have been evaluated for responses to P, and many clones with high level of adaptation to low P have been identified and included in crop improvement program . Later several dozens of cassava core germplasm have also been tested for their tolerance to low-K soils, with few clones with high level of tolerance have been identified . In the following subsections, data of many tested accessions for their tolerance of low-P and low-K soils, as well as responses to P or K fertilizer application, are presented. Current hydrological and GCMs models predict, within the next decades, the occurrence of extended drought periods across continents, coupled with irregularity in intensity and distribution of rainfall, as well as a possible increase in land area prone to drought in tropical and subtropical regions. This expected shortage in water resources, combined with rises in Earth’s surface temperature, will be significant enough to negatively impacts agricultural productivity and food security for the projected >9 billion world population , particularly in developing countries.

The inherent capacity of cassava to tolerate adverse environments, a comparative advantage over most tropical staple food crops, enhanced the expansion of the crop cultivation in more marginal areas in sub-Saharan Africa, Northeastern Brazil and other areas in Asia . Moreover, in the coming decades when experiencing globally warming climate, cassava will play even more important role, as other less adapted staple food crops will probably fail to produce reasonably.Cassava responds positively to elevated CO2 , and to high temperatures,two crucial atmospheric characteristics of climate change. Adaptation and mitigation measures then become essential approaches to obviate expected adverse effects of climate change,with the development of improved genetic and agronomic technologies being the main elements.The physiological research at CIAT have elucidated and documented the many mechanisms underlying cassava tolerance to abiotic stresses , and was pivotal in enhancing interests for expanding cassava production in semiarid areas in South America and Sub-Saharan Africa, areas where other main staple tropical crops such as cereals and grain legumes probably will fail to produce.

In our studies this could not be shown, probably because the organic matter contents and release of N were comparably small and thus system related differences were not visible against the general “noise” of spatial and temporal heterogeneity. Determination of the impact of tillage on WSA did not result in a clear-cut trend suggesting that reduced tillage and residue retention would always increase aggregate stability, as has been proven elsewhere. However, ambiguous results in regard to the influence of tillage and residue retention on WSA were also found by for Western Kenyan cropping systems under integrated soil fertility management.

A higher share of larger aggregates under ZT points towards better soil structure, which in turn positively affects soil water infiltration and retention—witnessed by our results on these properties. Further, more large aggregates in C16 than in B4 was most likely a positive effect of the higher SOM content in C16, as SOM is the glue that holds aggregates together. However, our observations show that WSAs change with soil depth. To reveal the underlying mechanisms further research is required to fully understand the impact of tillage on WSA of the high-clay, montmorillonitic soils of northern Syria, which are typical for the Mediterranean region. It was somewhat surprising that soil water infiltration capacity varied significantly over time, which basically meant, at least for the soils at ICARDA headquarters, that the applied method did not give consistent results complying with what could be considered saturated hydraulic conductivity. Also, quantities were much higher— at least a factor 10—than Ks-values established for the same soil .

Nevertheless, the consistency of results provides evidence about the soil ameliorating impact of ZT and residue management. An increased water infiltration capacity allows water to infiltrate deeper into the soil and diminishes water runoff and thus soil erosion. This has been known for many years, and has been shown in many other comparable studies, such as in Germany , USA , Australia , Poland , Argentina , and Mexico . On the other hand, observed surface crusting and decreased water infiltration under NT. Yet, despite reduced infiltration, their NT treatments still conserved more soil moisture during the dry fallow period than the tilled plots. also could not find any improvement in infiltration rate under ZT in comparison to chisel ploughing in Argentina. We tried to answer the question whether in addition to higher water infiltration capacity by reduced tillage and residue management a surface residue layer would conserve soil moisture.

During the late cropping season, high surface residue levels did not contribute to moisture conservation in the top 15 cm of soil, contradicting what has been reported elsewhere. However, increased crop transpiration—manifesting itself in significantly higher yields compared to the off-site control—could have confounded the results. After harvest, under fallow conditions, residues could in general not prevent the loss of soil moisture from 0 – 15 cm depth within about four weeks although moisture levels were some few per cent higher during the first three weeks under the plots with the two highest residue levels. This means residue retentionimpacted moisture in the top soil for a limited time only. Under fallow conditions the effect was still notable five weeks after application of 30 mm of irrigation water when including 15 – 30 cm depth into the calculation, but only if very high amounts of residue were retained; much more than can be produced on-site under dry rainfed conditions.

A temporary reduction of soil water evaporation during the cropping season when residues are retained should improve the crop-soil water balance by shifting water losses from unproductive evaporation to productive crop transpiration. However, a recent modelling study revealed that the impact is limited, not exceeding on average 10 – 15 mm per season that is transpired instead of evaporated . Corresponding yield data revealed that minimum tillage and residue retention translates into higher yields for all major crops of the region in the majority of years. Our data show that obviously this is due to the effect of an increased soil quality and more favorable soil water relations. Adequate, balanced nutrient management including crop nutrition by chemical fertilizer application is, of course, an underlying necessity. Our results provide evidence that SOM increased in response to N-fertilizer application, but further research is required to consolidate this observation.The lack of success of dams and embankments as a result of the use of dispersive soil has been recognized byengineers and geologists in South Africa and internationally for many years.