Horticulture

From the aquaponic facility at Caldwell, two water samples were collected per week: one from the fish tank and the other from the plant bed which was used to grow Romaine Lettuce, watercress, lettuce and green peppers. Similarly, from the facility at Bryan, three water samples were collected: one from the Tilapia tank, one from the Gold- fish tank, and the other from the main plant bed where lettuce and kale were cultivated. The aquaponic facility at Grimes was one of the largest in the state and four water samples were collected each week: one each from the main growth tank which was used for breeding Tilapia and certain shrimps, one from the tank which bred bluegill fish, one from the tank which was used to grow plant seedlings and the other from the main greenhouse where tomatoes, lettuce and collard greens were grown. All of these tanks were connected together with continuous water flow between them, and water purifiers were installed in each of these tanks to ensure that the recycled water meets the optimal water quality requirements needed for growth of fish and plants. A set up where the experiments were recorded have been shown in Fig. 1. The wastewater from the fish tank is connected to the main set-up, where extra nutrients are added to the aquaponic solution to optimize plant growth. After collecting the water samples, they were sent to the Soil, Water, and Forage Testing Laboratory, Texas A&M University to determine the nutrient concentration for each of the samples. The method used to carry out each of these nutrient concentrations in the laboratory is described as follows in Table 1. This process was carried out each week for 9 months and then the data were analysed. Before explaining the analysis part, a pipeline on how the data was processed to design the Decision Support System has been elaborately stated in Fig. 2 below.

As mentioned above, due to the limited size of the data-set, it is not possible to make accurate inferences taking all the predictors into account. Thus, several dimensionality reduction techniques have been used on the data-set to select the top predictors that define the nutrient concentration of the aquaponic solution. The predictors which had zero variance were removed from the data-set. Then, a correlation matrix was constructed between the predictors, and one of the two predictors, which had higher than 90% pair-wise correlation among them, stacking pots was removed. Next, all the predictors with less than 5% importance in the data-set were eliminated as they would likely incorrectly skew any inferencing made from the data-set. As the primary goal was to bring down the size of the data-set to 5 primary chemical predictors, Recursive Feature Elimination technique with XGBoost classifier was used, which ranked the predictors in the order of their importance. This resulted in bringing down the size of the data-set to 5 chemical predictors. In addition to this, 2 categorical predictors were also appended to the data-set, one storing the month and the other storing the place in which the observations were recorded. Therefore, a total of 143 observations with 7 predictors were used to design classification rules and carry out inferences.To perform any classification rules on a given data-set, Data Visualization is an important tool as it aids in understanding the structure of the data. It equally helps in choosing the classification techniques that can be used on the data-set depending on the separability between the classes. In this case, Principal Component Analysis was used. As PCA treats the entire analysis as an unsupervised learning approach and performs an orthogonal transformation of the data, Principal Components were calculated to visualize the variance in the data-set. The loading matrix was analysed to determine the predictor that contributes the most in each Principal Component and therefore, an inference can be drawn about the relative importance of each predictor from their holding values depending on the value of correlation, which was observed between the predictors and the respective PCs.

To further explore the interpretation from the PCs, the pairwise PC plots have been studied to infer which classifiers would suit the best depending on the pattern of separability of the data. All the data points belonging to class 0 have been color-coded in red and the data points belonging to class 1 have been color-coded in green to have a clear visual understanding of the binary distribution of the data.As stated above, the size of the data-set poses a serious issue while designing the classifier in this context, due to which, the classifiers have been trained and tested on the same data. This method of error estimation is referred to as Bolstered Error Estimation. One of the main reasons for choosing this type of estimator is its low bias as well as low variance. This also results in a faster estimator compared to other resampling methods like the bootstrap . The error estimates have been calculated for each of these estimators for the four popular classification rules by varying the size from small to moderate-sized data-sets. The basic idea is to bolster the original empirical distribution of the available data utilizing suitable Bolstering kernels placed at each data point location. For this case, a uniform zero-mean, spherical Bolstering kernel fi⋄ was chosen for analysis, with covariance matrices of the form σi2Ip. In each case, there would be a family of Bolstered estimators corresponding to each value of where i varies from 1 to n. Larger values of σi would result in wider Bolstering kernels resulting in lower variance estimators, but after a point, bias starts to increase. Therefore, choosing the values of standard deviations for the Bolstering kernels is a challenge and several approaches have been attempted to find the best error estimator in this case which minimizes the bias-variance trade-off.

As stated before, the entire approach was treated as an unsupervised approach and the K-means algorithm was used to classify the observations into two classes. Out of the 143 observations used for analysis, 84 were classified into class 0 and 59 into class 1. As it was difficult to derive inferences considering all the predictors, dimensionality reduction techniques were used. ‘Carbonate ’ was dropped as the variance was zero throughout. Then, a correlation matrix was constructed between the rest of the predictors. This led to the removal of 6 predictors from the data-set namely magnesium, both the measures of hardness, alkalinity, Total Dissolved Salts, and conductivity. Then, Extra Trees classifier was used to find the percentages of importance for each of the 14 predictors. Now, the predictors that had less than 5% importance were removed from the data-set. From the list of chemical predictors, Nitrates and Phosphorus, with the importance of 4.51% and 4.44% respectively, and from the list of chemical properties, pH, SAR, and charge balance with the importance of 1.2%, 0.93%, and 0.93% respectively were removed. Thus, the final list of chemical predictors used in the analysis was as follows: Potassium, Boron, Bicarbonate, Sulfate, and Chloride concentrations in the solution . In addition to this, 2 categorical predictors were also appended to the data-set, one storing the month and the other storing the place in which the observations were recorded. Therefore, a total of 143 observations with 7 predictors were used to design classification rules and to carry out inferences. Next, visualizations were carried out on the data-set to gauge the separability of the data and the classifiers which can be used for inferencing.

As inferred from Fig. 5, the first three PCs go on to explain 46.34%, 34.40%, and 9.36% of the total variance in the data-set respectively. The loading matrix was analysed to get an idea about which predictor contributes the most in each PC and therefore, an inference can be drawn about the relative importance of each predictor from their holding values. From Table 2, it can be inferred that the PLACE_CLASS, MONTH_CLASS, and the bicarbonate variables had the highest holding values in the 1st, 2nd, and 3rd PC respectively, indicating their strong correlations with the respective PCs. From this, one of the strongest inferences that can be drawn is that both the categorical predictors, one storing the place and the other storing the month in which the observations were recorded, are the most important predictors as they show high holding values in the first two PCs which explain about 80% of the variance in the data-set. To further explore the interpretation from the PCs, the pairwise PC plots have been studied to infer which classifiers would suit the best depending on the pattern of separability of the data. All the data points belonging to class 0 have been color-coded in red and those belonging to class 1 in green, giving a clear visual understanding that the data follows a binary distribution. From the PC plots, it has been observed that most of the discriminatory information is contained in the first PC, as expected, as it explains most of the variance in the data-set. Next, due to the low sample size,grow lights there is a high probability of over-fitting the data because of which, the notion of different Bolstered error estimators has been introduced in this domain. The performance of linear classifiers like LDA and Linear SVM along with the performance of non-linear classifiers like CART and 3-NN have been used along with these Bolstered error estimators, and results have been discussed below. The value of the depth of the decision tree was chosen as 2 due to the low volume of the data-set as a higher value of the depth would result in over-fitting the data and lead to unreasonably high accuracy on the training data-set.

The value of the K for the KNearest Neighbor was chosen to be 3 using Elbow method as the mean cluster distance on the training data-set was optimal.Eq. holds in the case of linear classifiers like LDA and linear SVM where the Bolstering kernels are given by uniform circular distributions. As the decision boundary in the above case is a hyperplane, it is possible to find analytical solutions as in . However, when the error estimate is made for non-linear classifiers like CART and KNN, an approximate solution is needed which is obtained by applying Monte-Carlo integration. The error estimates for all the four classifiers i.e. LDA, KNN, CART and Linear SVM have been tabulated and the results are shown below. The value of N i.e. the number of randomly sampled data points has been varied from 20% to 100% in increments of 10 for each of the classifiers. As shown in Fig. 7, the Bolstered Error Estimates reduced from 8% to 2.5% for LDA when the size of the sample set increased. For the nonlinear classifiers, it can be observed that they over-fit the training set due to their minuscule size thereby increasing the chance of the classifier performing badly on the testing set. Therefore, a decision not to proceed with either of these classifiers was made using Bolstered Error re-substitution as it is very likely to over-fit when the size of the data-set is small. Here, the opposite is observed when a linear SVC is used with different values of penalty parameters . Irrespective of the amount of data, the error estimates for each of the classifiers are around 50% which makes it unsuitable to be used as an ideal classifier for the separation of data between the classes as it showcases an ideal case of under-fitting.As the name suggests, in this type of error estimation, the classifiers are trained on each subset separately. Every subset contains all the data points belonging to one particular class except one which is used as the test data point. Therefore, in a binary classification problem, if m data points belong to class 0 and n data points belong to class 1, there will be a total of m-1 subsets for class 0 and n-1 subsets for class 1; and the classifiers will be trained separately on all of them. In the end, an aggregate of the error on each of these subsets is calculated to find out the total Bolstered Leave One Out Error estimate for each of these classifiers.

Bacopa monnieri Wettst., an extensively documented medicinal plant, for its nootropic properties had witnessed a burgeoned interest towards analyses of plant growth, role of culture conditions and elicitations on metabolites yield and their bio-activities.The growing disease burden of neurological disorders, especially in developing countries like India , further augment the need to explore the phyto-pharmacological importance of this plant. Last decade had witnessed extensive studies on the phyto-constituents in the extract of Bacopa monnieri, beyond saponin . Such studies are significant, owing to the vast therapeutic application, beyond nootropic ability, exhibited by the phytocompounds of Bacopa monnieri . However, some of the trivial bottlenecks, encountered while cultivation of Bacopa monnieri could be the variation in yield of phytocompounds. Such variation often evident in plant growth are primarily due to agro-climatic and genotypic variations along with seasonal variation in the yield of phytocompounds and the bio-activities of extract and herbal formulations.Tissue culture techniques have been optimized for the production of therapeutic phytocompounds rich biomass and studies are underway to explore a sustainable scalable solution to mass production of biomass rich in phytocompounds. These concerns obtrude exigencies for exploring alternative robust cultivation strategies. In order to circumvent the impact of cultivation conditions vis-a-vis improving the growth rate and yield of pytocompounds, there is a need to explore some innovative cultivation techniques.

Hydroponic culture, also called soil-less culture is obtruding as a well-accepted technique for improving growth and biomass yield in vegetables and herbs.Due to the slow, but steady integration and application of hydroponic technique for medicinal plants, scant information highlighting the role of hydroponic nft cultivation on growth and saponin yield is available. Maneeply et al. proposed the positive effect of NFT and DFT with higher growth and saponin accumulation than field cultivation, in hydroponic culture of Bacopa monnieri, in Hoagland’s solution. The need to explore alternative media composition and effect of abiotic factors that may synergistically affecting the growth of Bacopa monnieri have not been explored. In current study, the effect of Murashige and Skoog media, ‘Leafy 200’ hydroponic media and light intensity were explored, to design a robust bacosides production strategy using hydroponics.Bacopa monnieri  was chosen among the available geographical variants, for the study, due to comparatively higher saponin yield, reported previously.These plants were maintained in a pot, for a year, within campus premises. The chemicals, growth hormone and basal media were purchased from HiMedia, and methanol for phytochemical extraction was purchased from Qualigens Fine Chemicals Pvt. Ltd, . The experiments were conducted in phytajars containing 20 mL of Murashige and Skoog media. Hydroponic media, used in the study with brand name ‘Leafy 200’, was purchased from GreenLoop .

The amount of powdered media used to constitute 1x media solutions, were as per manufacturer’s instruction. The saponin standard ‘Bacopaside I’ used in the study was purchased from Natural Remedies, Bangalore .The milliQ water, used in the study, had resistivity of 18.3 Mohms cm 1 medium with 0.8% agar. Surface sterilization involved the treatment of explant with 0.1 % mercuric chloride for 30 s, followed by washing in sterile distilled water. The plant material was further treated with 0.1 % sodium hypochlorite for 40 s and again washed in sterile distilled water. Finally, the explant was washed with 70% sterile ethanol followed by washing with water. The sterile plants were inoculated on MS Agar media. The media also contained antibiotics viz., ampicillin and amphotericin B ; and 1mg.L 1 phytohormone BAP , as reported previously . The phytajars with sterile plants were propagated in the growth chamber maintained at 25 2 C, illuminated with white light with photoperiod of 12 h.The statistical design of experiment with 4-run experiment was performed and the phytajars with explants were incubated under specified conditions. The harvested plants, after 9-day acclimatization and growth under four different experimental conditions showed significant variations in morphology of the plants . It was observed that propagation of plant in MS liquid media under white and blue/red light showed significant variations in morphology and. Previous studies have reported the photomorphogenesis, due to three main families of photoreceptors, viz. phytochromes, blue-light receptor and less explored UV-B photoreceptors . Studies by Najafabadi et al. , highlighted the significance of red light on the growth and hypericins from in vitro culture of Hypericum perforatum. In another study, Macedo et al. , reported the contrasting effect of red and blue light on the leaf mass density in the tissue culture of Alternanthera brasiliana. Studies by Chrysargyris et al. , indicated the effect of nitrogen supplementation during hydroponic culture on plant growth, chlorophyll content and yield of essential oil, highlighting the need of plant specific optimization of the media.

Ronga et al. , reported the benefits of digestate on dry matter, aromatic compound and sesquiterpenes. The result in our studies showed more number of leaves and adventitious shoots in hydroponic media illuminated with white light. The leaf area and thickness of the leaves of plant cultured in MS media with white light were more other culture conditions. The explant in MS media under blue/red light showed stunted growth with small leaves. The effect of ‘Leafy 200’ hydroponic media was also evident in the morphologies of the harvest and showed morphological alternation and. The plant propagated in ‘Leafy 200’ hydroponic media under white light showed adventitious rooting from the nodes. Also in comparison to plant propagated under white light in MS media, the number of nodes and leaves in plant in ‘Leafy 200’ and white light are more.The results for the first time highlight the effect of light intensity and commercial hydroponic media on the morphogenesis of Bacopa monnieri. Further the effect of culture conditions on total saponin yield as also compared .The result of ANOVA showed insignificant variation in the yield of saponin cultured in both, MS media and hydroponic media . The results suggest that the yield of saponin is not significantly affected on changing the light intensity with either media. The study is important as it suggest hydroponic media ‘Leafy 200’ to be a cost effect substitute of costly tissue culture technique. Moreover, previous studies have shown that hydroponics or soil-less cultivation have provided a robust solution to the growing concern of variable plant growth or yield of phytocompounds thereof. Recently, Maneeply et al reported the high yield of active compounds and higher production of Bacopa sp. through hydroponic technique.

The strategy may be extended to further optimize hydroponic cultivation condition of highly demanded nootropic plant Bacopa monnieri. Moreover, the study to explore the molecular regulation of media components and light intensity for this high value plant will assist cultivars and farmers to mass cultivate the plant under optimized conditions. The effect of different abiotic components on bacosides yield was observed .Wastewater hydroponic system is the integration of wastewater treatment into hydroponic plant production . In a wastewater hydroponic system, nutrients generated from wastewater treatment through physical and microbial degradation are absorbed by plants. Using such synergies offer several advantages over other bioremediation/phytoremediation techniques such as constructed wetlands by producing value-added crops . As a wastewater-based hydroponic technology, it requires less area, it is inexpensive and can be implemented onsite . The hydroponic component serves as a secondary or tertiary treatment step for wastewater treatment thus minimizing the requirements for further purification of wastewater to levels acceptable for disposal standards. Hence, linking the two systems may offer sustainable options in which renewable resources such as water and nutrients recovered from domestic wastewater can be used for crop production. This will reduce energy and input costs which are commonly involved in conventional wastewater treatment plants and commercial hydroponic crop production systems, respectively . The use of wastewater effluents as nutrient sources for hydroponic channel crop production has been widely used as a form of domestic wastewater disposal . This practice has been recognised as one of the sustainable methods for wastewater management. Several studies have shown the potential of different types of wastewater as a source of fertilizer and irrigation water for the cultivation of green plants in the hydroponic system . In these studies, a number of crop species, including leafy vegetables , fruit crops and ornamental plants grown in hydroponic system have been reported to be suitable for wastewater hydroponic system. Results from these studies showed variation in nutrients removal, yield/biomass production and crop quality when compared to either conventional wastewater treatment or commercial hydroponic crop production system .

This variation is caused by a number of factors including, crop selection in terms of adaptability to grow in hydroponic systems and their tolerance to grow under wastewater of different qualities, the source and composition of wastewater used for agricultural irrigation and fertilization . The method of wastewater treatment before reuse is also reported to have an effect on crop performance irrigated with wastewater. Decentralised wastewater treatment systems which involve the combination of treatment and disposal of wastewater has gained attention in recent years . Such an approach allows for the reuse of treated wastewater within the source of generation and is designed to operate at a small-scale level, thereby offering sustainable opportunities for wastewater treatment especially for developing countries . This system involves a number of treatment stages/processes for the breakdown of waste fractions in a wastewater treatment plant. Among those processes, anaerobic digestion is regarded as the most important component of the DEWATS system due to its low requirement on energy inputs, low sludge production and the opportunity to recover nutrients from the effluents produced . This high nutrient load of wastewater generated through anaerobic digestion has prompted its use for agriculture, including the hydroponic cultivation of crops. Generally, higher plants require both macro and micro-nutrients to grow and reproduce to their full potential. The most essential elements required in sufficient amounts for tomato cultivation include, N, P, K, Ca, Mg, Fe, Zn. The demand for these nutrients is known to be higher in hydroponically grown crops compared to their field-grown counterparts. This is because field produced crops source a portion of their nutrients supply from the soil, whereas, in hydroponic production system, the nutrient requirements of the crop are fulfilled by the nutrient solution . Integrated wastewater treatment and hydroponic plant production systems that solely depend on wastewater to supply nutrients for tomato plants have been reported to be deficient in nutrients such as nitrogen, phosphorus, potassium and calcium .

This is attributed to the low content of nutrients such as N, P, K, Ca and Mg in wastewater effluents. In addition, the complex nature of tomato plants in terms of nutrient management which is highly variable than leafy vegetables are also known to be the limiting factor for growth and yield performance in wastewater hydroponic systems. The nutrient demand of tomatoes changes as the plants grow from germination, vegetative to the reproductive stage . From germination to first flower development, N, P, K are the most critical nutrients required by the plants while, K, Ca, Mg, Zn and Mn are required in sufficient amounts during fruit set. Most investigations have shown that the plant nitrogen content decreased significantly when digestates from organic manure were used as an alternative to mineral fertilizers under hydroponic systems , as well as in pot experiments . The reduction in N content has been related to differences in the composition of the digestate. However, NH4þ is known to be the dominant source of N for domestic wastewater hence its conversion to nitrate is required for hydroponically grown tomatoes . This is necessary because of the high sensitivity of tomatoes to high NH4þ –N levels. The low content and unavailability of Mg and P in wastewater effluents as a result of struvite formation and precipitation during anaerobic digestion were also reported to be the growth-limiting factor for hydroponically grown tomatoes . However, other studies have reported that supplementation of wastewater with deficient nutrients improved plant growth in hydroponically grown plants. The addition of P and micro-nutrients particularly, iron increased the shoot biomass of lettuce .

The tension meter was suggested to be placed vertically because the results from the tensile experiment were affected by the inclined angle of the tension meter. The tension meter was pull up slowly at a constant speed until the root of hydroponic lettuce was separated from the planting board. Then the maximum pulling force in this experiment was recorded. Thirty samples were randomly selected for the experiment. The sketch map and experimental field of the measurement method were shown in Fig. 3.Shear experiment was carried out to determine the necessary cutting force of a product with different cutting speeds and cutting positions when shearing the hydroponic lettuce root. The cutting force plays an essential role in designing cutting devices of harvesting machinery. The experiments were performed by using an electronic universal testing machine controlled by a computer, as shown in Fig. 4. The cutting angle was selected as 20 according to the actual cutting operation requirements. The root tip of hydroponic lettuce was connected with a tension meter. Then the root of hydroponic lettuce was slowly straightened. The tension value of tension meter is recorded as the specified tension when the root was just in a flat state, the sketch map and experimental field were shown in Fig. 5a and b, respectively. A single bevel blade with knife edge angle of 25 and made of carbon steel 0.5 mm thick was used in this study because of its strength and durability.

The hydroponic lettuce root could not be cut off when the cutting speed was less than 500 mm/min, but the cutting force tends to be stable with little change when the cutting speed was more than 900 mm/min. Therefore, the loading speeds of the cutting blade were selected as 500 mm/min, 600 mm/ min, 700 mm/min, 800 mm/min, 900 mm/min, respectively. The average MRL of hydroponic lettuce is 95 mm, the cutting positions were selected as 0 mm, 30 mm, 60 mm, and 90 mm away from the planting board, respectively. These position corresponds to MED0, MED3, MED6, and MED9, as shown in Fig. 1. The hydroponic lettuce root was fixed on a shearing fixture and it was cut with different cutting speeds. The root was moved to the next position after completing shear experiment of one position. Every experiment was repeated 3 times in different cutting speeds and different cutting positions combination, then average results were compared statistically.One-Way analysis of variance with Microsoft Office Excel 2016 software and Multi-Way analysis of variance with Design Expert 8.0 software were used for the analysis of variance of experimental data. In addition, a root cutting force model was built by a multivariate regressive method. The model was checked by an F-test in Design Expert 8.0 software.The moisture content was determined by the direct drying method.

The main distribution range of CD of hydroponic lettuce was from 300 to 359 mm, which accounts for 87% of the total samples; the main distribution range of OL was from 50 to 89 mm, 4×8 flood tray which accounts for 90% of the total samples; the main distribution range of pH was from 170 to 210 mm, which accounts for 83% of the total samples; the main distribution range of TH was from 450 to 569 mm, which accounts for 77% of the total samples; the main distribution range of TRL was from 240 to 359 mm, which accounts for 83% of the total samples; the main distribution range of MRL was from 80 to 109 mm, which accounts for 90% of the total samples; the main distribution range of SDi was from 11.0 to 14.9 mm, which accounts for 90% of the total samples; the main distribution range of MED3 was from 25.00 to 34.99 mm, which accounts for 94% of the total samples; the main distribution range of MED6 was from 45.00 to 59.99 mm, which accounts for 80% of the total samples; the main distribution range of MED9 was from 40.00 to 54.99 mm, which accounts for 83% of the total samples; the main distribution range of the total weight was from 130 to 179 g, which accounts for 80% of the total samples; the main distribution range of the net weight was from 120 to 169 g, which accounts for 77% of the total samples. The histograms of these data obtained from physical properties experiments on hydroponic lettuce were shown in Fig. 6, and the geometric parameters of hydroponic lettuce were shown in Table 1. The longest MRL was 114 mm. Therefore, the depth of the nutrient tank should be greater than 114 mm to avoid the influence on the growth of lettuce. The varying of PH and CD were significant. The maximum values of PH and CD were suggested to be referenced when designing harvesting machinery to avoid the failure of harvesting. The MED can provide support for the design of the cutting devices. The MED with 63.21 mm is required to be acceptable when the cutting device is fully open. In addition, planting density and root extension of hydroponic lettuce will also affect the growth of the crop. Therefore, OL,TRL, and TH can be referenced when determining the plant spacing and cultivation mode. To select a planting board with suitable strength, the weight should be used as a reference standard.

And the size of the planting hole in the planting board could be determined according to the maximum value of SDi of hydroponic lettuce. Meanwhile, it can be seen that the dispersion of physical parameters of hydroponic lettuce was small from the Coefficient of Variation less than 0.15. Therefore, harvesting machinery can be designed according to the main distribution range of physical parameters of hydroponic lettuce.The moisture content of hydroponic lettuce was high, but the value of different parts were quite different. The moisture content of leaf was considerably higher than root and stem, the average moisture contents were 95.73%, 91.71%, 91.85% for leaf, stem, and root, respectively, as shown in Table 2. The CV of moisture content of stem, root, and leaf were less than the reference value of 0.15, which means that the data were reliable in this study. Xiang et al. concluded that the moisture content of fresh-cut lettuce leaves was 96.8% during storage, which was similar to the result of this study. In addition, leafy vegetables with high moisture content were more likely to wither and rot. Therefore, the automatic equipment should finish harvesting and packaging as soon as possible to avoid the impact on the quality of the product. Besides, although the moisture content of the stem was the lowest, it was easier to break because of its small toughness. Therefore, more protection should be given to this part in harvesting and packaging.The maximum force and the minimum force of pulling hydroponic lettuce out of the planting board were 16.5 N and 9.6 N, respectively. The value of the average pulling force was 13.03 N with standard deviations of 1.85 N. The experimental data were within the normal range with CV was less than 0.15 specified in the evaluation data dispersion. The main distribution range of the pulling force of hydroponic lettuce was from 11.0 to 15.9 N, which accounts for 83% of the total samples, as shown in Fig. 7.

Shandong Agricultural University Hu reported the pulling force of spinach was 14 N with the soil moisture content was 12.3% during harvest. The harvesting style of lettuce was comparable with spinach. Therefore, the harvesting machinery of spinach can be referred to when designing the harvesting machinery of lettuce. In addition, the planting board may be pulled up together with the hydroponic lettuce due to the light weight of the planting board. Therefore, the planting board was suggested to be fixed during the experiment and the actual harvest to avoid harvest failure.Thirty results were obtained through the shear experiment, as shown in Table 3. The scatter distribution was shown in Fig. 8. The maximum and minimum root cutting force were 27.43 N and 1.41 N, respectively. The maximum root cutting force appeared under the combination of cutting position of 0 mm and cutting speed of 500 mm/min. The minimum root cutting force appeared under the combination of cutting position of 90 mm and cutting speed of 900 mm/min. Generally, the root cutting force of hydroponic lettuce increased with the increase of cutting speed, and also increased with the distance from the planting board decreased.The variance analysis of the regression equation for the root cutting force was shown in Table 4. The F-value of the model of the regression equation was 86.95, and the F-value as a reference can be obtained from the standard F distribution table, which was 18.51. This result means that the model was significant . Meanwhile, the effect of cutting position and cutting speed on root cutting force were significant with P-value less than 0.05. In addition, the F-value of cutting position and cutting speed were 148.85 and 25.04, respectively. The influence of cutting position on the root cutting force was more significant than cutting speed . The response surface method in Design Expert 8.0 was used to summarize the regulation of root cutting force. The response surface figure between the cutting speed, cutting position, and root cutting force was shown in Fig. 9. It can be concluded: for the same cutting speed, the farther the cutting position from the planting board, the smaller the root cutting force, ebb flow tray and for the same cutting position, the higher the cutting speed, the smaller the root cutting force. The minimum root cutting force was 1.41 N with the 900 mm/min of cutting speed and 90 mm of the distance between the cutting position and the planting board. Du et al. and Li et al.have reported the trend of root cutting force of cabbage with cutting position: root cutting force decreases with the cutting position close to the outer most leaf of cabbage, which consistent with the results of this study.

Meanwhile, the trend of response surface was unanimous with the result of variance analysis.The value of lettuce characteristic research can be used in the harvesting stage and packaging stage of hydroponic lettuce processing. The ideal result used minimum force to finish harvesting without damaging the hydroponic lettuce. The average value of the moisture content of hydroponic lettuce was more than 90%. To ensure the quality of lettuce, the harvesting and packaging processing should be shortened as much as possible. The minimum value of the pulling force of 16.5 N can be applied effectively to ensure the hydroponic lettuce can be pulled out successfully. The planting board should be fixed to avoid pulling out together with hydroponic lettuce during harvest. The values of the root cutting force indicated the necessary forces to cut off the root with different cutting positions and different cutting speeds. The F-value of cutting position was 148.85, but the F-value of cutting speed was 25.04. The influence of cutting position on the root cutting force was more significant . To save energy, a further away from the planting board position should be selected to cut.Hydroponic growth system is a versatile platform to study plant behavior under controlled conditions. It is a convenient system for not only controlling the plant nutrition but also provides an excellent model for researchers to study root system and its responses under different environmental conditions. Certain hydroponic systems have been developed for Arabidopsis and other crop species to study their behavior under various environmental stress conditions. To our best knowledge, only few studies were available on trees species which were grown hydroponically under controlled environment. Based on existing knowledge, we have modified/ customized hydroponic system for Pongamia seedlings. Pongamia is known to possess elongated tap root and lateral root system. To accommodate Pongamia tap root system and without facing the root inhibiting effect, we have designed new experimental system. Our method was uniquely designed to perform tree species stress studies with minimal resources. Pods of P. pinnata accession TOIL 12 were obtained from Tree Oil India Limited , Zaheerabad, Hyderabad, Telangana.

Leaf area, photosynthetic potential and crop growth rate are important indexes for representing the photosynthetic capacity of a population. Wu et al.  suggested that the leaf area, photosynthetic potential and population growth rate of superhybridized japonica rice were significantly greater than those of Shanyou 63 control rice at the middle and late stages. Huo et al.  reported that, with a delayed sowing date, the LAI significantly decreased at the JS, HS and dough stage and slightly decreased at the MS. The photosynthetic potential significantly or extremely significantly declined from sowing until the JS and from the JS to the HS. The cropgrowth rate markedly increased from sowing until the JS, and no significant difference was observed from the JS to the HS, whereas the rate decreased significantly from the HS to the MS. The net assimilation rate noticeably increased from sowing until the JS and from the JS to the HS but noticeably decreased from the HS to the MS. However, few reports exist on the effects of seedling age at transplanting on the photosynthetic production characteristics of mechanically transplanted HLMS.

In this research, with increasing seedling age, the LAI decreased for both cultivars at the HS and MS, the photosynthetic potential also decreased from the TS to the JS and from the JS to the HS, and the crop growth rate decreased from the TS to the JS, flood table except for 6 Liangyou 9368 in 2015. No obvious pattern of differences in crop growth rate was observed from the JS to the HS, but the rate was greater for the young seedlings than for the old seedlings from the HS to the MS. With increasing seedling age, the Pn markedly decreased at the HS, but there was no significant difference in Pn between the 13- and 20-day-old 6 Liangyou 9368 seedlings.Selenium  is an essential micro-nutrient for maintaining human health . When enters in metabolism, Se can enhance the anti-carcinogenic capacity of the human body . Vegetables and cereals are important sourcesof Se for humans. However, the low bioavailability of Se in the soil in some areas restricts Se accumulation in vegetables and cereals , which leads to inadequate Se intake levels to possibly prevent cancer . Se deficiency in the diet is a worldwide problem, especially in China, the UK, Eastern Europe and Australia . Therefore, there is an increasing demand for Se-enriched food . Vegetables play important roles in the human diet.

The consumption of Se-rich vegetables could be a safe and effective way to solve the problem of Se deficiency. It is known that plants can uptake Se in the form of selenate, selenite and organic species . The exogenous application of Se has been particularly effective in increasing the Se concentration in plants, but this effect varies among species . An excessive intake of Se can also lead to chronic toxicity for humans, with the recommended daily maximum intake of dietary Se not exceeding 400 mg per day . The target to regulate the Se concentration in vegetables is still therefore unknown. Consequently, there is an urgent need to develop adaptive agricultural strategies to regulate Se uptake and distribution in vegetables. Nitrate is one of the main forms of nitrogen used for plant growth and development and is widely used in vegetable production, especially in leafy vegetables grown in hydroponic systems . Lettuce  is the main crop grown in greenhouses and is consumed worldwide due to its flavour and high levels of phytochemicals. However, lettuce is a hyperaccumulator of nitrate and easily accumulates a large amount of nitrate in its leaves . The daily consumption of vegetables with high amounts of nitrate is associated with a higher risk for cancers and methemoglobinemia . In our previous study, we reported that exogenous Se application had a positive effect in restricting nitrate accumulation in hydroponic lettuce . However, little is known about the relationship between Se accumulation and nitrate reduction in plants under different forms of exogenous Se.

Light is not only the driving force for photosynthesis but also serves as the transduction signal to regulate metabolism in plants . Compared with light intensity and light duration, light spectra have more complex roles in regulating plant growth and development . To date, red and blue light emitting diodes  have been proven to be the most efficient artificial light source for driving photosynthesis and are widely used in vegetable production . Previous studies reported that the light spectral composition plays an important role in regulating the accumulation of mineral elements, such as N, P and K in plants . However, few studies have focused on the effect of light spectra on Se uptake, translocation and accumulation under different forms of exogenous Se treatment. In this study, we conducted a selenate concentration screening experiment and then comparatively investigated the effects of the light spectral composition and Se forms on the uptake, translocation and accumulation of Se, nitrate metabolism and photosynthetic performance of lettuce grown hydroponically. The main objectives of this study were to:  investigate the effect of the combination of light spectra and Se forms on the accumulation and distribution of Se and nitrate reduction and  investigate the relationship between the light spectral composition and the nitrate/ Se content in lettuce under different forms of exogenous Se treatment.

The results of this study are crucial to understanding and revealing the mechanisms that are responsible for Se uptake, distribution and toxicity in plants. Furthermore, the information from this study can provide guidance on producing high nutritional quality vegetables with safe Se concentrations.In the main light experiment, the plants and previous growth conditions were the same as above. At the end of the dark period of day 21, similar size seedlings were transplanted into 25-L containers with 0.5 μmol L–1 selenite  or 10 μmol L–1 selenate  in Hoagland solution. These plants were grown under different light spectra for 25 days. There were five different LED light treatments: monochromatic red LED light , monochromatic blue LED light , combined red and blue LED light with a red to blue ratio at 4 , 8  and 12 , respectively. The plants exposed to FL were used as controls. The details of the light spectra from the light sources used in this study are summarized in Appendix A. The light intensity at the plant canopy was monitored every other day using a light intensity metre . The light intensity was maintained at 200 mmol m–2 s−1 by changing the distances between the light sources and plants. Other environmental factors were the same as those at the seedling stage. There were three replicates with a total of 48 plants per treatment. The nutrient solution with the same Se treatment was replaced every 5 days.The RCF and TF could be used to reflect the capacities for Se uptake, accumulation and translocation in response to the light spectra and exogenous Se. The RCF and TF of Se were significantly affected by the light spectral composition and applied forms of Se.

Regardless of the concentration difference, the RCF for exogenous selenite was approximately 5 times higher and the TF was 6.8–11.9 times lower than that for exogenous selenate.With regard to the selenate treatment, the values of RCF and TF in the plants exposed to red and blue LED were lower than those under FL. The RCF of Se under R/B=8 was markedly higher but the TF of Se was lower than that under the other LED light spectral treatments. Interestingly, these parameters for the plants under R/B=4 changed in an opposite direction compared to those for R/B=8, as shown by the lowest RCF and highest TF under R/B=4. These results indicate that R/B=8 was more efficient in promoting Se absorption, while R/B=4 was more effective in promoting Se transportation in lettuce plants. In contrast, the highest and lowest RCF of Se under exogenous selenite was observed in the plants exposed to R and R/B=4, respectively. However, the RCF under the other light treatments was comparable to that under the FL treatment. Compared with FL,rolling benches red and blue LED light  led to significant decreases in the TF of Se in the plants treated with exogenous selenite, and the lowest TF of Se was observed under R.No significant difference was observed for the total nitrogen  content under different light spectra and exogenous Se treatments . However, the nitrate contentsand N assimilation enzyme activities in the lettuce leaves were markedly affected by the Se forms and light spectral composition . The nitrate contents in the lettuce treated with selenate were lower than those under selenite, indicating that compared with selenite, exogenous selenate was more efficient in retarding nitrate accumulation in the lettuce plants. Relative to FL, the nitrate contents were significantly lower under red and blue LED light. Interestingly, regardless of the Se form, the lowest nitrate content was observed in the plants exposed to R/B=8. NR activity was significantly affected by the light spectra, applied Se forms and their interaction.

The NR activity of the plants treated with selenate was higher than that under the selenite treatments. The highest and lowest NR activity were observed under R/B=8 and B, respectively, after exogenous selenate and selenite application. Unlike the changes in NR activity, NiR activity was mainly affected by the light spectral composition. The highest NiR activity was observed under R/B=8, while this parameter under the other light treatments was comparable to that under FL. The activities of GS and GOGAT under LED light  were higher than those under FL. The highest GS activities were observed under R/B=8, while the GOGAT activities were the highest in the plants exposed to B for both the exogenous selenite and selenate treatments.Under the exogenous selenate and selenite treatments, the Se and nitrate contents in the lettuce leaves  were both negatively correlated with the percentage of red light from the light sources . However, there was a significant linear relationship between the Se and nitrate content under exogenous selenate and selenite combined with different light spectral compositions . These results indicate that the accumulation of Se and nitrate were regulated by the light spectral composition and that a higher ratio of red light was not conducive to Se and nitrate accumulation in lettuce.Se is an essential mineral element for both humans and animals and is mainly acquired from plants . Exogenous Se application can increase the concentration of Se in the edible parts of plants. However, Se has not been proven to be an essential mineral element for plants, and excessive Se can be toxic. In this study, the effect of selenate on lettuce growth was concentrate-dependent: low concentration  promoting growth and high concentration  inhibiting growth.

These results are consistent with those of previous studies showing that a small amount of Se is beneficial for plant growth, while excessive doses could induce a decrease in the photosynthetic capacity, ultimately leading to reduced biomass or even plant death . In the present study, the significant effect of the light spectra and the concomitantly marked interaction between light spectra and Se forms on most of the plant biomass parameters indicate that the light spectrum plays an important role in the process of Se regulation of plant growth. Under mixed red and blue LED light, the higher biomass of selenatetreated plants observed in our study is partly attributed to their high photosynthetic capacity, as shown by higher Pn under selenate than under selenite . Similar results were also reported in wheat by Kaur and Sharma . Compared with other trace elements, Se is arguably one of the most interesting elements because of the very narrow window between deficiency and toxicity . An excessive intake of Se in the diet can also be harmful to human beings and animals . The ability to control Se concentration at safe levels in the edible parts of plants is important, alongside promoting Se accumulation in plants. In plants, mineral element uptake and translocation are regulated by many factors. Light can strongly affect plant cell potentialsor fluxes of ions other than those associated only with energy . Previous studies have found that the uptake capacity of mineral elements of plant tissue was affected by the light spectral composition .

Higher antioxidant activity has been measured in ginseng leaves and fruits than in roots, possibly in association with the 4e9-fold higher phenolic contents of fruits and leaves than roots. However, the beneficial effects of these phenolic compound-rich fruits and leaves remain unclear. Short-term hydroponic-cultured ginseng is a widely available, eco-friendly plant that cultivated in pesticide-free indoor farms. Unlike typically grown ginseng, which is usually sold in the form of dried roots, sHCG is harvested as a whole plant, consisting of roots, stems, and leaves. Ginseng roots contain high levels of ginsenosides, whereas the stems and leaves contain high levels of phenolic compounds; therefore, sHCG has a nutritional advantage over ginseng because all parts of the plant are used. Our previous study reported that sHCG, in the form of 1-year-old ginseng seedlings grown hydroponically for 21 days, exhibited higher antioxidant activity than 5-year-old ginseng plants. Contents of total ginsenosides and four ginsenosides  were significantly higher in sHCG than in 5-year-old ginseng. Additionally, sHCG has an almost fourfold higher total phenolic content compared to 5-year-old ginseng.

However, the beneficial physiological effects of sHCG are not clear. Several variable factors determine the extractability of saponin, such as temperature, solvents, extraction time, and the liquid to solid ratio. However, it is difficult to determine which factor is most important due to their complex interactions. Therefore, led grow lights response surface methodology  has been used to determine optimal extraction conditions in studies attempting to maximize the yield of saponins from medicinal plants and Rg1 and phenolics from RG. However, to date, no study has evaluated the extraction conditions for sHCG and the bio-activity of the extract. In this study, the optimal extraction conditions for sHCG were evaluated using RSM modeling, with the aim of maximizing the yields of bioactive compounds abundant in sHCG but present at lower levels in white ginseng  and RG. Additionally, pilot-scale sHCG extracts were produced using the optimal extraction conditions for future commercial production and the effects of the extracts on TNF-a/IFN-ginduced TARC levels in human keratinocytes were evaluated as indicators of AD disease severity.Fifty-one phenolic compounds were extracted from sHCG, WG, and RG, and analyzed using ultra-high-performance liquid chromatography-tandem mass spectrometry by reference to a database of mass-fragmentation patterns. The CGA content was markedly higher in sHCG than in WG and RG.

HPLC-UV quantification revealed a CGA content of 12.7 mg/100 g dry sHCG, which was 2.5- and 13.3-fold higher than the contents in WG and RG, respectively . Similarly, Chung et al. reported that of 23 phenolic compounds, CGA and p- and m-coumaric acids were the major phenolic compounds detected, particularly in leaves of ginseng aged 3e6 years. Because only roots of WG and RG were analyzed, the higher content of CGA in sHCG may be attributed to the leaves. CGA is biosynthesized and stored during the early stages of leaf development in other plants, such as coffee trees and perforate St John’s wort. Therefore, it is reasonable to assume that the ginsenoside and CGA contents are higher in sHCG containing leaves and stems cultured in the early growth period than in conventionally grown ginseng and RG. In addition to CGA, 22 ginsenosides of sHCG were profiled in our previous study, and 4 ginsenosides  were selected as representative bioactive compounds. These four ginsenosides and CGA are known to be anti-inflammatory, antioxidant and immune enhancing agents. AD is a chronic inflammatory skin disease caused by impaired immune regulation, genetic abnormalities, and hypersensitivity to environmental factors such as allergens. Keratinocytes are epidermal cells that play a critical role in maintaining epidermal barrier function, thus protecting the body from allergens and pathogens. When stimulated by immune triggers , keratinocytes release inflammatory mediators  and macrophage-derived chemokines.

TARC/CCL17 and thechemokines promote penetration of inflamed tissue by T cells. In particular, TARC/CCL17, which has high affinity for CCR4þ T cells, is found only in AD lesions; higher levels are associated with more severe AD. To examine the AD-preventing effects of CGA and the four ginsenosides, it was evaluated whether secretion of TNF-a/IFN-ginduced TARC/CCL17 was decreased by the treatment of HaCaT cells with CGA and the four ginsenosides. Treatment of HaCaTs with 2 and 4 mM CGA signifificantly reduced TNF-a/IFN-g-induced production of TARC/CCL17 by 32% and 45%, respectively . Also, Re, Rg1, Rb1, and Rd at 10 mM significantly reduced TNF-a/IFN-ginduced TARC/CCL17 production in HaCaTs by 28%, 38%, 31%, and 22%, respectively .The milk thistle Silybum marianum Gaertn., synonymous Carduus marianus L., is an annual or biennial plant. The plant is native to the Mediterranean region; however, it was naturalized elsewhere in the world . The fruits of this plant accumulate isomeric mixture of flavonolignans in their outer shells. Silibinins, isosilibinins, silydianin and silychristin are the major flavonolignans produced by S. marianum fruits. The standardized extract of the fruits is known as silymarin, which is an important pharmaceutical raw material used for oral treatment of liver disorders. This plant was placed in 2016 at the sixth position among the top-selling herbal dietary supplements in the natural and health food market and the sixteenth position in the mainstream multi-outlet channel market in U.S.A., at about $9.968 million and $17.077 million, respectively .

In consideration of the market requirements for a standardized product with a high content of bioactive principles, several efforts are directed to the setup of suitable growing conditions for stimulation of plant secondary metabolite production.Therefore, the development of an alternative growing system could be an effective tool to overcome the drawbacks linked to open-field cultivation . Hydroponics is a growing system, in which the nutrient elements that are normally found in the soil are dissolved in a proper quantity of the irrigation water supplied to the plants. Hydroponic is also known as ’soilless culture’, because the plants are cultivated in pure nutrient solutions or in artificial growing media  instead of the common agricultural soil . With more isolated condition and well-defined composition in this technique, the management of important growing parameters such as surrounding climate or nutrition represents a significant tool for the regulation of secondary metabolism. In particular, a proper change in the composition of the nutrient solution could stimulate the secondary metabolism and favor the accumulation of bioactive compounds inside the tissues.A further major advantage of hydroponics is the possibility to expose the plants to stress factors that can elicit an increase in the concentrations of secondary metabolites .

Among the most remarkable representatives of elicitors is salicylic acid which is a natural plant stress mediator that can highly improve the production of pharmaceutically active compounds in plants . It successfully enhanced silymarin production in S. marianum in vitro cultured cells in MS liquid medium but not previously used in hydroponic culture. Nutrient film technique is one of the hydroponic types in which the plants are housed in net pots that are placed on channels having the nutrient solution. The nutrient solution is pumped though the channels and constantly running along the bottom of the channel and the roots are not completely submerged . Hydroponic culture of medicinal plants aiming at production of important secondary metabolites is rarely reported.Nuclear magnetic resonance spectroscopy can provide useful qualitative and quantitative information in analysis of complex mixtures such as plant extracts. Quantitative proton nuclear magnetic resonance spectroscopy  can offer an overview of the sample composition through quantification of multiple metabolites without the need for chromatographic separation. This method, orthogonal to the high-performance liquid chromatography  analysis, allows quantification of targeted compounds without the need of reference materials . So, the objectives of the present study were to establish a hydroponic culture protocol for S. marianum as one of the medicinally valuable plant species using nutrient film technique; enhance plant capacity to accumulate flavonolignans using salicylic acid as elicitor and determine the influence of the hydroponic system, vertical grow system as a different cultivation technique and elicitation on seed productivity and silymarin yield which was achieved by comparing the flavonolignan content in different cultures using qHNMR and HPLC techniques.

In addition to, provide a demonstration of the effect of salicylic acid on biosynthetic pathway leading to flavonolignan production.Different salicylic acid treatments were supplied to each single plant and the plants were randomized on one nutrient film apparatus so that each single plant was a biological repetition. Salicylic acid was added at concentrations of 100, 200 and 400 lM, into the nutrient medium when the plant is at BBCH growth stage 75. Nonelicitor treatment was considered as the control culture. The mature fruits of the cultured S. marianum plants were collected at BBCH growth stage 88, 5 d after the elicitor addition. Sampling was performed individually from each single plant and further fruit analysis was performed at single plant level.In the past 40 years, numerous strategies have been developed to improve plant productivity using in vitro culture techniques such as elicitation . However, there are no reports for the use of these strategies in hydroponic system. In the present study, hydroponic culture was successfully established from the seedlings at BBCH growth stage 14 using nutrient film technique system . The results of measuring different factors for flower-head and seed proved that milk thistle productivity significantly affected by hydroponic system and elicitation treatments . Considerable increase in these factors was achieved by elicitation of the hydroponically cultured plant using 200 mM salicylic acid than field-grown plant . The most interesting observations for the hydroponic culture was its ability to produce fast plant growth with high biomass. In addition to, the feasibility to control the growing environment and to change the composition of the nutrient solution, when it was necessary to treat the nutrient solution with elicitors, because the nutrient elements are readily available at the root zone and can be easily taken up by the plants. The flavonolignans contents in the fruits of different cultures of S. marianum were analyzed using both qHNMR and HPLC. Both techniques were reported to be used interchangeably to quantitate flavonolignans in the silymarin complex .Quantitative analysis in NMR depends on the fact that the integrated intensity of a signal due to the analyte nuclei is directly proportional to its molar concentration and to the number of nuclei that give rise to this signal. The direct proportionality of the analytical response and molar concentration is one of the main advantages of qNMR as a method for quantification over other spectroscopic methods. In UV spectroscopy, for example, the concentration is related to the molar absorptivity which is different for each molecule. Therefore, we have to obtain pure reference standard for each compound of interest. In qNMR, a single standard can be used to quantify many components in a mixture, which can be even structurally unrelated to the analytes under investigation, contains the nucleus of interest and has a resonance that does not overlap those of our target analytes. Silibinin was used as a reference standard.

The 1 H NMR data of the compounds under investigation in this study has been previously published . The chemical structures of flavonolignans under investigation in the present study are shown in Fig. 3. The flavonolignan contents in the fruits of hydroponically cultured plant are shown in Table 1. Silychristin, silibinin and isosilibinin were the major flavonolignans detected in the fruits of the cultured plants while silydianin was not detected.  estimated the silymarin content in the field-grown fruits collected from Cairo – Alexandria Road between 11.02 and 15.54 mg/g DW in which silychristin and silibinin/ isosilibinin were 2.77–3.17 and 3.03–6.38 mg/g DW respectively. Taking in consideration the variation due to re-cultivation in different habitat in Beni-Suef governorate. Elicitation of the hydroponic culture with salicylic acid at different concentrations  enchanced the production of these flavonolignans in the fruits. A dose of 100 mM salicylic acid added to the hydroponic cultures of S. marianum for 5 d increased total silymarin content 1.4-fold higher than the control. The highest content of total silymarin was observed after addition of 200 mM salicylic acid for 5 d. This is considered as 1.7-fold higher than in the control.

Similar to mineral wool, pumice is also a neutral material containing less than 1% organic matter. Thus, it showed minimal sorption affinity to most of the studied compounds during the initial contact time. Caffeine is a notable exception. We speculate that caffeine’s low molecular mass allowed high mass transfer into pumice’s large number of pores. Some limitations to this study are apparent, and limit a complete mechanistic interpretation due to lack of statistical significance in some kinetic and sorption equilibrium data. In order to obtain mass balances and insights in reversibility of ad- and desorption, we suggest to identify suitable elution agents for these novel substrata to conduct desorption experiments. Furthermore, this study did not specifically investigate the effect of phosphate buffer on sorption. Previous studies report that phosphate sorption is inhibited on adsorption sites due to surface complexation with metals and repulsion of phosphate ions by negatively charged organic matter . However, specific adsorption of phosphate could also occur by ligand exchange with surface hydroxyl groups. Also, cation bridges may also increase phosphate sorption sites and may result in competitive interaction for sorption sites between phosphate and micro-pollutants . Further study is required to get more insights into this.Organic substrata wood fibre and coconut fibre sorbed micro-pollutants more than the inorganic substrata mineral wool and pumice .

A similar order of sorption affinity for trimethoprim, carbamazepine and sulfamethoxazole was found for soils by Kodešová et al. . Ibuprofen and naproxen, containing -COOH groups, and sulfamethoxazole, containing -SO2-NH moieties, hydroponic dutch buckets have acidic protons which can dissociate and form anionic species . Subsequently, a strong repulsion occurs between these anionic species and negatively charged surface of the organic substrata. Although sulfamethoxazole has a basic NH2 group , it has acidic protons due to the presence of an acidic -NHand an electron-withdrawing -SO2- in the vicinity. The presence of two basic NH2 groups in trimethoprim explains its highest sorption affinity. Carbamazepine has one amido group and the basicity of an amido group is lower than of an amino group. This could explain the sorption order: trimethoprim is followed by carbamazepine. Caffeine has a lone pair of electrons at the non-methylated N site . Therefore, caffeine acts as a proton-acceptor, basic, so it is positively charged and attracted to the negatively charged surface.The hydrophobicity positively affects the sorption . Therefore, carbamazepine is followed by caffeine in the sorption order. The sorption of micro-pollutants on organic rich materials appears to be a trade-off between electrostatic interaction and hydrophobic interactions between the organic matrices and the micro-pollutants.

This is further depicted in a four quadrant matrix . In the high pKa and high Log Kow quadrant, both electrostatic interactions and hydrophobicity positively affect the sorption, as indicated by high KF values for carbamazepine on the organic substrata.For the low pKa and high Log Kow quadrant, the positive effect of hydrophobicity of iburprofen and naproxen appears to be largely counteracted by strong electrostatic repulsion due to deprotonation . At the quadrant of high pKa and low Log Kow, an intermediate sorption on the organic substrata was observed for caffeine and sulfamethoxazole. In this study, no compounds falling into the low pKa and low Log Kow quadrant were investigated. We speculate based on our results, that even lower sorption is to be expected for compounds in this quadrant on our selected substrata. Inorganic substrata mineral wool and pumice generally exhibited much lower sorption and slower sorption kinetics towards the studied micro-pollutants. Mineral wool is a non-reactive neutral material. Therefore, unlike wood fibre and coconut fibre, mineral wool has no extensive net negative surface charge. Furthermore, mineral wool has the lowest surface area among all the substrata . These properties together explain the low sorption  of the micro-pollutants. Similar to mineral wool, pumice is also a neutral material containing less than 1% organic matter. Thus, it showed minimal sorption affinity to most of the studied compounds during the initial contact time. Caffeine is a notable exception. We speculate that caffeine’s low molecular mass allowed high mass transfer into pumice’s large number of pores.

Some limitations to this study are apparent, and limit a complete mechanistic interpretation due to lack of statistical significance in some kinetic and sorption equilibrium data. In order to obtain mass balances and insights in reversibility of ad- and desorption, we suggest to identify suitable elution agents for these novel substrata to conduct desorption experiments. Furthermore, this study did not specifically investigate the effect of phosphate buffer on sorption. Previous studies report that phosphate sorption is inhibited on adsorption sites due to surface complexation with metals and repulsion of phosphate ions by negatively charged organic matter . However, specific adsorption of phosphate could also occur by ligand exchange with surface hydroxyl groups. Also, cation bridges may also increase phosphate sorption sites and may result in competitive interaction for sorption sites between phosphate and micro-pollutants . Further study is required to get more insights into this.Selection of suitable substrata is important when designing CWs like systems. Substrata with a high sorption capacity efficiently remove a variety of pollutants, including micro-pollutants. Generally, higher Kd values for the six selected compounds were obtained on the organic substrata . These values were compared with the available literature data for natural sorbents, like soil . Kd values of wood fibre and coconut fibre for the selected compounds were mostly 5-20 times higher than that of soil. High Kd values suggest a larger partitioning of the micro-pollutants onto the organic matter. When compounds can accumulate on- and into the substrata, they would have a strongly retarded mobility in the solid-liquid matrix of a filter bed .

This characteristic of the organic substrata illustrates the suitability of organic hydroponic substrata for use in wastewater treatment technologies. For example, CWs could be amended with such a substrata filter to mitigate the emissions of micro-pollutants to the environment. Wood fibre is particularly suited for application in CWs. To illustrate this, we compared two generic CWs with either wood fibre or soil as a filter bed and determined the theoretical removal of carbamazepine and trimethoprim from wastewater . These compounds were selected considering carbamazepine’s recalcitrance in conventional wastewater treatment plants and presence of trimethoprim residues in wastewater may lead to the development of antibiotic resistance,bato bucket affecting human health and environment. Based on the calculations, hydroponic substrata like wood fibre have a great potential to remove micro-pollutants by sorption, which could reduce the size of a CW. A wetland constructed with wood fibre requires significantly less surface area to achieve the same micropollutant removal as a wetland using soil. A wood fibre wetland requires only 35% and 66% of the surface area of a traditional CW to remove trimethoprim and carbamazepine respectively from the wastewater . It is important to mention that under natural conditions, there are multiple compounds competing for available sorption sites on a substratum. Also, additional removal mechanisms, like biodegradation and phytodegradation would play a role in the removal of these compounds. Therefore, it is recommended to study the sorption behaviour of the substrata and micro-pollutants at trace concentrations taking into account the natural conditions that may restrict sorption, and other additional removal mechanisms that may support micro-pollutant removal. Additionally, to optimize the treatment performance of the envisioned CWs, further studies on the operational parameters, for example, hydraulic loading rate, hydraulic retention time and plant types, are recommended .Globally, current food consumption and trade are placing unprecedented demands on agricultural systems and increasing the pressure on natural resources. This circumstance requires trade-offs between food security and environmental impacts, especially given the tension between market-driven agriculture and agro-ecological goals .

Intensive greenhouse horticulture has spread in response to the year round demand for fresh agricultural food products. The total area of greenhouse cultivation in the EU increased at a rate of 4.5 % between 2005 and 2013, reaching 210,000 ha in 2018 . Inthe Mediterranean region, greenhouse cultivation constitutes the most productive form of primary agricultural production, where a total area of about 120,000 ha was registered in 2016 . For several decades, the greenhouses in Almería region  have been the main driver for its socio-economic and demographic development. Annually, its 31,000 ha of greenhouses, which represent 14.7 % of the total covered surface in the EU, produce more than 3 million tons of fruits and vegetables , generating a value of almost €2 billion . This fruitful business is currently facing significant challenges in terms of sustainability. This is partly related to the new environmental demands of customers and markets, but the main issue is the fragility of the natural resources, especially fresh water . Additionally, uncontrolled underground water withdrawal and non-efficient fertigation plans have caused a decrease in water resources quantity and quality. The water quality deterioration is mainly caused by in-depth filtration of fertilizers and phytosanitary products . In order to address the problem of water quality deterioration and overexploitation, research has mainly put the focus on the development and implementation of management practices aimed at reducing nitrate leaching and regulating water withdrawals from the aquifer. For instance, Gallardo et al. and Granados et al.  reported a reduction in nitrate discharge to the environment through the accurate management of the leaching fraction and nitrogen supplies in horticultural crops. Later, Mag´ an et al. supported that finding by showing that with correct management of nitrogen and irrigation, nitrate leaching was reduced by 63 % compared to conventional management. In addition, research has shown desalinated seawater as a viable option for irrigating fruits and vegetables in greenhouses that can help to alleviate aquifer over-exploitation.

Facing these issues requires a good insight into the behaviour of agricultural systems and how their inputs and outputs may impact the environment . Accordingly, farmers and managers of agri-food businesses must understand the impacts’ sources and how to deal with them in order to optimise the production systems . In this sense, Life Cycle Assessment is the reference method to quantitatively evaluate the environmental impacts across the entire supply chain. It enables the comparison of different production systems in terms of resource-use efficiency and environmental effects. For agri-food systems, LCA is also increasingly being used to evaluate and analyse food security issues . The ISO standards  provide guidelines to perform LCA studies so as to guarantee their objectivity. Several studies using LCA in agriculture have evaluated the environmental impacts of greenhouse tomato cultivation. Some examples are: the evaluation of the use of different nitrogen fertilizers in hydroponic and soil production systems with open and closed loop systems , the comparison of greenhouses, screenhouses and plastic tunnels for cherry tomato production ,the irrigation with brackish desalination water versus conventional water ,the footprint estimation of increasing nitrogen doses for hydroponic tomato and the environmental assessment of rooftop greenhouse tomato with water-harvesting systems . Nevertheless, none have yet applied LCA to quantify the environmental impact of recycling effluents using reverse osmosis powered by photovoltaic solar energy.

The aims of this study are as follows: Firstly, to quantify the potential environmental benefits of the implementation of an on-farm solar-powered drainage treatment plant to recycle effluents from hydroponic tomato versus the traditional soil cultivation; Secondly, to explore, from an environmental perspective, the pros and cons of the use of desalinated seawater as an alternative to locally available brackish groundwater; and Finally, to carry out a sensitivity analysis to assess the potential environmental benefits of increasing the use of renewable energy for desalinated water production and curbing the common over-fertilisation malpractice reported in the study area. Two cultivation systems were used: i) conventional soil: sanded soil called ‘enarenado’, commonly used by farmers. This soil is a mix of clay, manure and sand arranged on top of the original soil base ; and ii) hydroponic system: coconut fibre substrate in bags. The most common fertigation management for both cultivation systems by farmers in Almeria is a free-draining open system . However, in our experimental design, the effluent of the HS was collected and driven to a tank. Once the tank was full, the effluent was then treated in an on-farm reverse osmosis system plant fully powered by photovoltaic solar panels .

Therefore, the systems showed greater bacterial diversity. Microorganisms gradually adapt to the environment and accumulate, resulting in an increase in bacterial community richness with the extension of culture time. At the same time, the dominant flora gradually occupy the dominant position, resulting in a decrease in the diversity of bacterial communities. The higher the concentration of LOFL was, the lower the bacterial community richness was, indicating that an increase in LOFL will inhibit the reproduction and growth of microorganisms. LOFL stimulates variation in microorganisms and the emergence of drug-resistant strains, resulting in a higher diversity of bacterial communities. Highly enriched microorganisms contribute to a high degree of pollutant removal. The bacterial community composition of the three reactors is shown in Fig. 2. Obvious differences among reactors with different LOFL concentrations, temperatures and operation times can be observed. At the phylum level, Proteobacteria was identified as the dominant phylum. Proteobacteria play a key role in biological nitrogen and phosphorus removal and the removal of other pollutants . Firmicutes and Actinobacteria are typical electrochemically active bacteria  phyla . However, the content of Actinobacteria increased from 0.5% to 2.7%  to 2.8− 53.9%  at normal temperature in this study. Normal temperature is beneficial to the growth of Actinobacteria. Firmicutes has a stronger ability to adapt to low-temperature environments. At low temperature, the percentage of Firmicutes in the seven reactors was 1.2–10.0%, while at normal temperature, the phylum appeared only at 10 and 100 µg/L concentrations.

The relative abundance of Firmicutes and Actinobacteria in MFC-CWs was higher than that in CWs.Wetland-electrochemical systems have a stronger pollutant removal ability than CW systems. Therefore, it is speculated that Firmicutes and Actinobacteria may be the key phyla. Different types of genera are greatly affected by antibiotic concentrations. The specific proportions of different genera are shown in Table S1. Rhodocyclaceae has been reported to be capable of using oxygen or nitrate as an electron acceptor in the denitrification process,ebb flow tray and short-chain fatty acids are usually used as electron donors . Rhodocyclaceae was enriched at lower silver nanoparticle  concentrations , which was similar to this research. Rhodocyclaceae was enriched at 0.1 µg/L  and 0.2 µg/L . Dechloromonas, Pseudomonas and Flavobacterium contain species that have denitrification capacity . They have been found frequently in constructed wetlands . Calheiros et al.  used constructed wetlands with Iris pseudacorus plants to purify winery wastewater, and the content of Pseudomonas in the plant rhizosphere reached 27.3%. Santos et al.  found that the abundance of the genus Novosphingobium increased in all exposed substrates, and several strains of this genus have already been described as capable of resisting and even degrading several compounds, such as tetracycline and bisphenol A . In this research, Novosphingobium accounted for only a small proportion  and was not the dominant genus. Phosphorus uptake by plants can be promoted by Rhizobacter. Secretions such as extracellular phosphatase and organic acids can convert insoluble phosphate into dissolved phosphorus, which can be absorbed by plants . From this point of view, such conversion can not only alleviate the blockage of phosphorus adsorption on the substrate surface but also generate economic value in resource recovery by CW plants and realize fully effective plant harvest and phosphorus removal. Dechloromonas has been identified as an abundant genus in many constructed wetland studies.When the silver nanoparticle  concentration increased from 0 to 50 μg/L, the relative abundance of the genus Dechloromonas increased.

However, when the concentration of AgNPs reached 200 μg/L, the relative abundance of the genus Dechloromonas decreased. Therefore, the ability to reduce nitrate or nitrite to nitrogen gas under autotrophic conditions decreased. Dechloromonas have the ability to biodegrade nitrogen without organic matter and exhibit phosphate-accumulating and chlorate-reducing capabilities  in reactors. Candidatus_Accumulibacter has been confirmed as the dominant polyphosphate-accumulating organism  in WWTPs and laboratory-scale reactors . Candidatus Accumulibacter can store volatile fatty acids  as polyhydroxyalkanoates  under anaerobic conditions and use PHAs as polyphosphate stores for the growth and regeneration of glycogen in the subsequent aerobic phase . Members of the familyChromatiaceae do not have internal cell photosynthetic membranes, but maintain globules of elemental sulfur inside the cells . Chromatiaceae can be found in benthic environments beneath the surface of photosynthetic bacterial mats or in planktonic environments below the anoxic–oxic interface of stratified lacustrine to hypersaline waters . There was a layer of green plankton on the surface of the plants and device walls in the system. The discovery of Chromatiaceae may be related to the presence of phytoplankton in the system. Burkholderiaceae is an ammonia-oxidizing bacteria  that has the ability to reduce ammonium and nitrite by nitrification and ammonia oxidation, and it can be found in a variety of aquatic and terrestrial environments . Burkholderiaceae plays an important role in the growth of wetland plants and is beneficial for carbon turnover and nitrogen fixation . The abundance of Burkholderiaceae was 38.8% in the research of Liyan Di, which was higher than that in this research . Acidovorax has been reported to be enriched at high concentrations of Cd stress , and it promoted Ni removal from soil . In this study, it was found that with increasing temperature, Acidovarax was inhibited. The genus Pseudomonas is a typical heterotrophic nitrifying bacterium that exhibits an efficient heterotrophic nitrification-aerobic denitrification capacity.

Inorganic nitrogen  or organic-N can both be growth substrates for Pseudomonas. The path of Pseudomonas denitrification is that it ammonifies organic-N to NH4+-N and then converts NH4+-N to NO2− -N or even directly converts organic-N to NO3—N . Nitrate reduction  is driven by narG, nirK+ nirS and nosZ. Nitrification was the rate-limiting step for denitrification due to substrate limitations . Ammoxidation is an important step in nitrification for NH4+-N removal . The heat map  indicates that there were obvious differences in the bacterial communities among the different conditions. The meaning of each letter is explained in Fig. 5. The relationship between the functions of microorganisms in the system and LOFL concentration, temperature, and contact time is shown in Fig. 5 . In terms of system function, culture time and the concentration of LOFL were the main influencing factors, while temperature was the secondary factor. Changes in conditions will lead to changes in the cellular functions of the bacterial community structure. For example, with increasing LOFL concentration, the translation ability, ribosomal structure, biogenesis, intracellular trafficking, secretion, vesicular transport, energy production and conversion, amino acid transport and metabolic ability of microorganisms were enhanced. However, transcription, replication, recombination and repair, cell cycle control, cell division, chromosome partitioning, coenzyme transport and metabolism and other abilities were inhibited. With the large-scale production and widespread applications of plastic products, increasing amounts of plastic are entering the natural environment . Plastic debris becomes brittle and fragmented under the exposure of ultraviolet  light and oxygen, as well as physical action from wind and waves . These plastics gradually degrade into micrometer- and nanometer-scale particles. Many studies confirm the worldwide occurrence of microplastics in marine environments , sediments , freshwater , groundwater , and soil . In freshwater, the main microplastics found are polypropylene , polyethylene , polystyrene , and polyethylene terephthalate.

Microplastics affect plants in the environment . Qi et al.  found that both low-density PE and biodegradable plastic mulch films of macro- and micro-size were harmful to wheat  growth. One of the toxicity mechanisms of microplastics to plants is the blockage of the root surface pores caused by adhesion to plant roots, which affects adsorption of nutrients . For nanoplastics, the uptake and accumulation of nanoplastics may affect the transport of nutrients. For instance, 100-nm PS nanoplastics block cell connections or cell wall pores, causing oxidative damage and genotoxicity in fava beans  . The adsorption and aggregation between microplastics and microalgae are also considered as the reasonable explanations for toxic effects of microplastic on marine microalgae . Meanwhile, PE and biodegradable plastic mulches improve raspberry plant growth and yield . These findings suggest that the toxicity of microplastics may be related to their type, particle size and concentration. Many experiments have demonstrated the adsorption of metals on microplastics. For example, Cu2+ and Zn2+ can adsorb on the surface of PET microplastics . The adsorption isotherm of Cd2+ onto PE microplastics follow Langmuir model , while Freundlich model is more suited for that of Cd2+ onto PET microplastics . It has been found that the adsorption of cadmium onto microplastics is closely related to the functional groups on the surface of microplastics, the solution pH and the ionic strength . Polycyclic aromatic hydrocarbons , generally produced by the partial burning of organic substances, resistant to degradation, ubiquitously present in the environment, pose a concern due to the toxicity and are potentially carcinogenic to humans . Soils contaminated by PAHs are mainly responsible for the continuous formation of environmentally persistent and relatively stable free radicals . It has been reported that these chemicals could enter the plant roots from the polluted soils and be transferred to the aerial parts subsequently . Two-photon excitation microscopy was employed for tracking the acquisition of phenanthrene  from the polluted growth medium into the roots of maize  and wheat  for two months . The study revealed the binding of Phe to the epidermis in the elongation zone, flood and drain tray then traversed the epidermal cells radially to reach the cortex of the root hair and branching zones of the root, and subsequently mobilized slowly and laterally to the shoot.In China, people’s exposure to PAHs and the related cancer risk due to the consumption of rice is much higher compared to that in other countries.

Cultivation of rice augmented thedissipation and transport of PAHs . In rice, PAHs were more readily absorbed by the root than adsorbed on the surface, and their level was relatively higher in the lateral root than in the nodal root . The analysis for a sampling of various rice tissues revealed a higher accumulation in the roots compared with the aerial tissues of rice cultivated in the PAHs-contaminated field . Among the macronutrients, phosphorus  is a vital component of various organic molecules , plays a key role in signal transduction and metabolic pathways, and is thus vital for the growth and development of plants . Membrane-localized phosphate  transporters  belonging to the PHOSPHATE TRANSPORTER1  family facilitate the acquisition of Pi, which is the available form of P in the rhizosphere . Intricate crosstalk was demonstrated between the essential macronutrients  and the uptake and translocation of Phe in wheat . The crosstalk between P and PAHs was also evident in rice as indicated by an adverse effect of PAHs on the phospholipid metabolism, which triggered damage to the cell membrane and consequent growth inhibition . The activities of the PAH-biodegrading bacteria are also influenced by the carbon /P/N ratio in the contaminated soils . These studies highlighted the prevalence of crosstalk between P and PAHs in taxonomically diverse bacteria and crop species. Therefore, it was intriguing to assume a likely role of the molecular mechanism involved in the acquisition and mobilization of Pi from the roots to shoots, and its crosstalk effect on the tissue-specific accumulation of Phe in rice grown in the Phe-contaminated rhizosphere. In model plants , phosphate overaccumulator2  is a ubiquitin-conjugating  E2 enzyme that has been implicated in regulating the Pi transporters during the mobilization of Pi from the roots to shoots . The concentration of Pi in the leaves of OsPHO2 knockout mutants  was significantly higher compared with the wild-type , which provided evidence of OsPHO2-mediated mobilization of Pi from the roots to shoots . Therefore, the likely role of OsPHO2 in the translocation and accumulation of Phe under different Pi regimes was assumed. For empirical evidence, the effects of mutation in OsPHO2 on the temporal translocation and accumulation of Phe were investigated during growth under different conditions . By comparing the Phe and P distribution in the WT and the mutants, the results provided evidence that Phe translocated and redistributed through the OsPHO2-regulated P translocation pathway in rice.

These prior studies demonstrate the importance of rainfall to chemical dilution of wastewater in the land treatment reservoirs and receiving waters relative to upstream watershed sources of unplanned water reuse such as septic systems, livestock waste management, and agriculture. The extended exposure of chemicals to sunlight, biological degradation, and mixing for 10–14 days in reservoirs merits notation when comparing chemical number and abundance of wastewater from this land treatment system to conventional wastewater treatment. Studies have linked unplanned water reuse in watersheds to anthropogenic COC presence in food crops, particularly corn, wheat, and soybean . Compagni et al.  coupled two distinct models, a water quality and plant uptake model, to estimate concentrations of 13 pharmaceuticals in edible plant tissues from repeated simulated crop irrigation of surface water downstream of permitted municipal wastewater discharge to evaluate COC risk to food crops from unplanned water reuse. Model estimations of COCs in plants agreed with literature data of COC transfer to leaves more so than roots or fruits; overall, human health risks from dietary intake were negligible based on toxicological thresholds of concern or hazard quotients except for sulfamethoxazole and 17a-etyinylestradiol . Montemurro et al.  reported that earthworms did contain COCs from soils amended with spiked COCs in tapwater, but only bisphenol A was detected in earthworms collected and analyzed from actual municipal wastewater irrigated soils.

The literature and our observations emphasize the pervasive presence of anthropogenic COCs in watersheds and the need to evaluate comparative risk of COC uptake in wastewater-irrigated plants to other watershed irrigation sources for drinking water sources . Since 2015, about 20 published studies per year address COC uptake by plants for pharmaceuticals, ebb and flow bench personal care products, and PFAS . A majority of these studies utilize hydroponics  or greenhouse soil studies  with spiked COC solutions to understand COC translocation to roots, shoots, and fruits. Field studies of COC uptake to plants from wastewater are poorly represented  but warranted to understand realistic COC uptake and dietary risk from repeated irrigation applications to food crops . Physio-chemical properties of COCs greatly influence COC transport in plants from irrigation water and irrigated soils to food crops. COCs with moderate log Kow of 1–5 transport to plant leaves and stalks via transpiration streams and will leach from irrigated soil to groundwater . Our recent review of hydroponic COC studies comprising 7 leafy vegetables and 39 COCs shows that polar, smaller COCs translocate more to shoots and leaves and that COCs with higher log Kow values cannot be ignored in food crop leaves and fruits. Collectively, the targeted literature and our non-targeted analyses show a similar range of log Kow values for COC detection in leafy tissues and fruits for food plants irrigated with wastewater. For past targeted studies, translocation factors were less than 0.04 for ToxCast chemicals with log Kow values less than 5 and between 0.1 and 0.4 forToxCast chemicals with log Kow values between 2 and 4 . In our nontargeted study, the majority of TICs and ToxCast chemicals extracted from soybean leaves, beans, and roots had log Kow values between 2 and 4.

A recent Monte Carlo simulation of perfluoroalkyl acids to edible plants and a proposed tiered framework of PPCP risk via edible plant ingestion prioritized PFAs and PPCPs with moderate log Kow values and estimated translocation factors greater than 0.1. The latter review recommends more nontargeted studies to assess the accumulation and transformation of PPCPs in edible plant tissues and better represent chemical mixtures present in wastewater. In our non-targeted study, hundreds of TICs and more than a hundred distinct ToxCast chemicals were detected in plant tissues. Both TICs and ToxCast chemicals represented a diversity of log Kow values and chemical use categories from tap water, wastewater, groundwater, and surface waters.Passive samplers have provided integrated COC assessments in aquatic system and often detect more chemicals at lower concentrations with less analytical clean-up prior to instrument analysis than conventional liquid-liquid or solid phase extraction of water samples . Passive samplers not only improve COC detection and representation over time in a given water source, but samplers can estimate COC concentrations in target organisms such as mussels, fish, worms, and plants . Previous studies found strong correlations of chemical uptake between samplers and soil organisms but variable correlations of chemical uptake between samplers and plants . In this study, the majority of ToxCast chemicals detected in CIPS had log Kow values between 2 and 4. Combining passive sampling with suspect screening HRMS  allows for more representative COC exposure analysis to humans and organisms . HRMS analysis of silicone wristbands is promising for human exposomics to workplace exposure . Coupled passive sampling with SS-HRMS and targeted HRMS evaluated pesticides in agricultural watersheds during drought , COCs in sediment pore water , COCs in surface-, ground-, and waste waters , and COCs in marine waters . SS-HRMS analyses of POCIS samplers yielded 65 tentatively-identified chemicals compared to 35 TICs from grab samples .

When specific sorptive dynamics are measured for a specific COC, time-weighted concentrations in water can be determined from the sampler . Alygizakis et al. contends that wastewater irrigation of crops should use passive samplers coupled to HRMS to assess COC risk to food crops. This study demonstrates the integration of passive sampling with HRMS and hydroponic assays to improve our knowledge of COC uptake to edible plant tissues and to expand our knowledge of COC dynamics in agro-food systems . A variety of passive samplers exist, such as Chemcatcher™, polyethylene strips , polyoxymethylene, polydimethylsiloxane, polar organic chemical integrated sampler  and composite integrated passive sampler , and can improve assessment of COC translocation to plant tissues from conventional and novel irrigation sources.The rapid growth in population and subsequent increase in water and energy consumption to meet the demand for products and services have resulted in resource depletion and environmental deterioration. Consequently, the study of what is known as the energy, water and food  nexus has gained significant interest over the last few years as a potentially effective approach for the management of resources considering the inherent interlink ages that exist between them. As such, the integrated analysis will enable the identification of key synergies and trade-offs that may exist in the design and operation of EWF resource systems . In addition, the EWF nexus approach is holistic, such that it aids decision-makers in pre-empting unintended, and possibly damaging, consequences resulting from the interventions made in any part of the nexus system. Thus, there is a need for implementing efficient and resilient resource management systems based on an optimization framework that considers environmental, economic and societal aspects of sustainable development in achieving the EWF resource security .

EWF Nexus and decision-making tools, such as optimization,agent-based modeling and game theory are important for effective integrated resource management . This is especially significant for the State of Qatar, with it its highly arid climate and inconsistent distribution of resources; whilst it is rich in energy resources, it suffers from water scarcity, environmental and food security challenges. Moreover, Qatar is now looking at extensively developing its agricultural capacity despite the risk of climate and resource stress impacts . This study proposes a geospatial nexus approach to support decision-making for resource management in risky environments and demonstrates its application in a case study for Qatar. Within this methodology, a novel concept is developed, referred to as the “EWF nexus node”. Each node represents a food system, which is a function affected by exogenous risks, such as climate, water and land factors. Based on the food production sector, the data related to spatial risk factors are collected from different data sources that are either in the form of maps from hard copy books or electronic formats, such as reports and peer-reviewed journal publications. The data is then digitized and integrated into a unified geo-processing platform, enabling both visualization and further processing of the risk factors. Other data types used include, districts and roads, industries, water resources and weather station locations. The assignment of weights that represent the importance of various risk factors is conducted using a multi-criteria decision-making method, known as the Analytical Hierarchy Process , in order to generate the composite geospatial risk indicators. The variabilities in risk maps are also captured for various seasons. Finally, the node assessments are conducted using these maps to assess the risk levels, productivity and the consumption of water and energy for various food production scenarios. Thus, the overall quality of the node is assessed based on the developed composite indicators, assessments, and the ability of the nodes to optimize for risk mitigation and adaptation. It is envisaged that the proposed EWF Nexus node approach will identify specified locations that perform better than others under risks. This paves the way for further optimization and decision-making to reduce the impact of endogenous and exogenous risk factors, thereby enhancing the resilience of EWF systems on a national level.

There exists a growing concern about the limited availability and access to energy, water and food resources, and the inequalities in their distribution as outcomes of poor management and inappropriate governance structures . Thus, an evidence was provided that the nexus approach helps improve energy, water and food security, through integrated management and governance across various scales and sectors. In addition, the nexus approach can also support the transition to a green economy, through the reduction in negative environmental,4x8ft rolling benches social and economic externalities, hence, overall leading to efficient utilization of resources and better policy coherence . The EWF nexus assessment is used to assess and evaluate the nexus interlinkages and highlights synergies between sector interferences at any scale. Existing indicators are usually used to measure and quantify these linkages. However, in case indicators for the desired level or scale are not available, then new and specific indicators will be developed . According to the Organisation for Economic Cooperation and Development , any variable that is observable and measurable can be later transformed into an indicator, which is a value with specific purposes that represent the variables themselves . Studies showed that indicators are the alternative to a direct impact measurement , where they have the ability to perform various functions. Within sustainable development, indicators are important to provide perspectives on environmental, economic and social performance . In fact, there are many dedicated models that assess the status of sustainable development, for instance, the Index of Sustainable Economic Welfare which were used to analyse the impact of used resource  or to study the sustainability of specific sectors or sub-sectors such as organic food consumption . In terms of assessing the sustainability of agricultural systems and environmental impacts of agricultural activities, several indicator-based methods have been developed, such as water pollution by nitrates and pesticides; in order to address the risk of pesticide . Furthermore, indicators can be used within geographic information systems  in order to determine spatial extension and geographic distribution of areas and to relate anthropogenic activities to environmental impacts .

The performance of energy, water and food sectors within national boundaries has been traditionally analysed separately, where indicators focus on a specific resource type such as energy , or water . For instance, the United Nations and World Bank provide number of indicators, although providing a partial view of the sector’s resources and do not fully consider the interrelationship between the sectors. However, in order to understand the state of sustainable development for a region or country, it is vital to quantitatively combine information pertaining to energy, water and food sectors . In order to achieve a rapid nexus appraisal and measure the performance of a system in terms of efficient resource use, then indicators for each type of intervention can be quantified using specific tools, such as input-output, modeling and information resources tools . In this regard, several indices provide information on the status of EWF nexus within the analysis of resources security, such as the WEC Energy Trilemma Index , the Water Exploitation Index Plus  and the FAO Food Price Index .

Therefore, based on those experiments, and taking into account the highest recommended doses of the selected products according to their labels, ground losses for each selected formulation were estimated as indicated in Table 2 and applied using a manual sprayer to each soil column. After application, a rainfall event of 120 mm was immediately simulated during a period of 2 h to imitate an average rainfall event from the Tarragona region for the treatment months. 2 L of rain water were supplied to each soil column. The leachate water from each column was collected in consecutive 200 mL samples, and the water leaching time was recorded. A second experimental process was repeated one week later, only in the sandy soil columns, increasing the time between fungicide application and rain event simulation to 24 h, to study the interaction of the pesticides with the rhizosphere. In this case, leachate water samples were collected every 500 mL, as a lower concentration of the fungicides was expected. As in the previous study, the time between water sample collection was recorded. The mass balance of the leached PPPs was calculated for each soil column condition, taking into account the amount of fungicide losses and the concentration contained in each active ingredient. The experimental results were statistically analysed using RStudio .

The Shapiro–Wilk test was used to check the normal distribution of the variables and their homoscedasticity. ANOVA test was performed to compare differences between the different hypotheses. HSD Tuckey test was conducted to find the group means that are different from each other. The same procedure was applied to analyse the statistical differences between the soil leaching flowrates and the hydroponic study results. Although 6 fungicides were applied on the soil surface,indoor garden only 3  were detected in the leached water from the sandy soil columns, and only one  was leached through the loam soil columns. Oxathiapiprolin, laminarin, and acibenzolar-S-methyl were not detected in the leaching water from any of the studied soil columns and conditions. The absence of these compounds in the leachates could be due to the low calculated ground losses taking into account the recommended application dose,but also to the high soil sorption coefficient in the case of oxathiapiprolin  and the high biodegradation rates described for laminarin and acibenzolar-S-methyl in aquatic and soil environments . Fig. 2 indicates that copper shows a linear increasing trend for the three column types  in both soils, whereas dimethomorph and zoxamide behave differently in bare soil columns than in vegetation covered soil columns. Both accumulated leached synthetic fungicide products continued to maintain the linear trend in cover cropped soil while bare soil columns showed a sigmoid curve for dimethomorph and an exponential curve for zoxamide. This may indicate that at the beginning, the bare soil columns were capable of retaining greater amounts of these fungicides, but later on, the retention capacity of cover cropped columns were greater.

The mass balance assessment shows that fungicides  leached through the cover cropped sandy soil columns by a range of 7–64% . Specifically, dimethomorph was leached from 37 to 64%, whereas these leaching values were 16–21% for zoxamide and 7–15% for copper. These results are in agreement with pesticide leaching values found by Singh et al.  in packed soil columns  for metolachlor and terbuthylazine . The greatest leaching of dimethomorph in comparison to zoxamide is in accordance with the reported sorption coefficient for these compounds.Although our results show a high dependence on soil texture, no significant differences were observed between covered soil columns and bare soil columns in sandy soil. These results are in disagreement with Dousset et al.  who found that lower amounts of pesticides leached through cover cropped soil columns  than bare soil columns . These differences can be explained due to the soil composition. While our sandy soil has a sandy-loam texture, the soil used by Dousset et al. had a sandy texture, and as it has been seen in Table 3, the texture of the soil affects the water leaching rates, thus the leaching of the fungicide products. Futhermore, differences in cover species types or water loading rates employed in each study can explain fungicide mass leaching differences. However, mass balance studies performed on loam soil columns show that fungicide leaching was much lower than that from sandy soil columns, probably due to the longer soil interaction time  as well as the higher organic matter and clay content of the loam soil, except for Cu which showed greater mass leaching in the loam soil columns. It is important to notice that loam soil had a very high concentration of copper , whereas it was low in sandy soil , so copper leaching was strongly affected by copper soil composition. The greater retention of fungicides by loam soil is in agreement with different studies that have found that organic matter and clay play a relevant role in enhancing the soil retention of pesticides and copper . Furthermore, our results show that the use of covers on loam soils significantly reduced the amount of copper leached through the columns  probably due to the longer water soil contact time in these columns .

Since no differences on fungicide leaching between cropped and uncropped columns were found when a rain event was simulated immediately after fungicide application in sandy soil columns ,we tried to observe if the same behaviour occurred with a 24 h elapsed between application and rainfall, as this is conventionally done as a cultural practice in a real vineyard. The sandy soil columns were chosen because they resulted in the highest fungicide leaching rates . Fig. 3 shows that the leaching of fungicides in bare soil columns is greater after 24 h of application than when the rain event was produced immediately after the application . This is mainly due to the accumulation of fungicides in the soil, as the second study was performed only one week after the first one. Even so, the fungicide mass leaching in the covered soil columns were lower than in the first study. In fact, our findings show that applying fungicides 24 before rain event resulted in a significant reduction in the amount of leached fungicides  between covered soil columns  versus bare soil columns . Despite this, no statistical differences were observed for dimethomorph, most likely due to the compound’s very high overall leached amount . Furthermore, results show that although there are no statistical differences between covered cropped strategies  for the leaching of zoxamide, monoculture covered columns resulted in a greater reduction of copper leaching than those observed in polyculture covered columns. This is in agreement with the fact that raygrass is a metal-accumulating plant , but also due to the fact that MC columns had greater root biomass than PC columns . Overall, our study demonstrates that the presence of cover crops significantly reduce the quantity of fungicides leached through the soil.

This can be explained by the positive effect of the plant rhizosphere in biodegradation as well as the plant uptake of synthetic and ecological organic fungicides . Therefore, since covers do not act as a physical resistance against product leaching, it seems that the attenuation of potential groundwater contamination occurs when the fungicide-rhizosphere interaction time is as long as possible prior to a rainfall event to allow phytoremediation to take place. Different hydroponic studies were performed to assess the direct impact of vegetation on the attenuation of fungicides without taking into consideration soil interaction. The concentration decay of fungicides in hydroponic containers followed a first-order kinetic with concentration decay rates ranging from 0.06 to 0.63 d− 1 and half-lives from 1 to 21 days . These kinetic rates are in the range of those found in other hydroponic studies that explored the impact of rooted crops on the attenuation of pesticides . Fungicides can be classified as highly degradable , moderately degradable  and poorly degradable . Acibenzolar-s-methyl was the fungicide with the highest kinetic decay rate  in any of the studied hydroponic conditions, indicating that this is a highly degradable compound as it was suggested in previous soil leaching studies where it was not detected . Similarly, oxathiapiprolin and laminarin showed kinetic rates of between 0.2 and 0.5 d− 1 for rooted hydroponic containers, indicating moderate biodegradability. In this regard, for laminarin, the presence of roots enhanced the concentration decay from 0.06 d− 1 in the control containers to 0.22 and 0.34 d− 1 for the rooted MC and PC containers, respectively. This positive effect of roots may be explained by the increase in biodegradation due to the root exudates or the plant uptake of this highly polar compound . Finally, dimethomorph and zoxamide were only poorly removed. These findings are consistent with results from leaching studies where these two fungicides and copper were the only ones that leached through soil columns. Overall, hydroponic farming studies show that dimethomorph, zoxamide, and laminarin are highly affected by the presence of rooted crops , indicating that covering has a highly positive impact on enhancing concentration decay, either by biodegradation, sorption, and/or plant uptake.

These results are in agreement with previous hydroponic studies carried out by Lv et al. , who found that the concentration decay of fungicides such as tebuconazole and imazalil is enhanced by the use of highly rooted plants like Phragmites australis. Furthermore, our studies show that using a mixture of cover spices  enhances the reduction of dimethomorph under hydroponic conditions. This last finding suggests that plant biodiversity may aid in enhancing soil bioremediation . The removal of fungicides in the hydroponic studies after 10 incubation days ranged from 36 to 98%, so that at least 36% of all tested fungicides degrade after that time. Similarly, the findings for kinetic rates in removal results show that vegetation has a significant positive effect on all tested fungicides, with the exception of oxathiapiprolin. The reduction in concentration of zoxamide, dimethomorph and acibenzolar-s-methyl due to the presence of vegetation increased by 27–51%, 108–148% and 42–50%, respectively. For laminarin, elimination is gathered with the root action, practically reaching total elimination after 10 days , but with a low degradation in the control containers . Overall, hydroponic results indicate that cover crops roots are capable of enhancing the removal of almost all studied fungicides, whereas increasing plant biodiversity can play a relevant role in improving the attenuation of dimethomorph.Furthermore, fungicide application practices are very relevant for enhancing the crop covering effectiveness. Therefore, our results suggest that fungicide spraying should be performed at least 24 h before rain forecasting. This is in line with the European strategy to reduce the use of pesticides and soil pollution. According to Chapagain et al. , covers minimize soil disturbance and erosion, improve soil structure and water-stable aggregates, and support pollinators and beneficial insects, among other things. However, Sharma et al.  noticed that over crops can be problematic in some points, including the method of killing, host for pathogens, regeneration, and not immediate benefits of using them.

There is also a concern about water competition concerns between the main crop and the cover crop. But according to Delpuech and Metay , even in the Mediterranean region, where most vineyards are located, the implementation of a cover crop strategy is feasible. The growth of the human population places an ever-increasing demand on freshwater resources and food supply. The nexus of water and food is now well recognized. One promising strategy to sustain food production in the face of competing water demands is to increase the reuse of treated human wastewater. Municipal wastewater reuse for food production has been successfully adopted in some regions of the world. For example, Israel uses ~84% treated wastewater in agriculture production . However, Southern California, a region that suffers from a similar degree of water shortage, currently uses less than ~3% of municipal wastewater in agriculture, while discharging ~1.5 million acre-feet effluent per year into the Pacific Ocean . Secondary municipal wastewater effluent for ocean discharge is often sufficient to support both the nutrient and water needs for food production.

Some weeks later, as no clinical improvement was noted, the lemur was anesthetized to perform a more detailed examination. A big firm mass was revealed in the epigastrium by the abdominal palpation and it was confirmed by radiographs: a large radiopaque mass about 3 – 4 cm in diameter. Two days later a laparotomy was performed: the mass completely occluded the intestinal wall and was removed through intestinal resection and anastomosis . Consequently to this surgery, the subject showed a slight recovery from the illness  then it became again anorexic and did not accept fragmented/homogenized food. Therefore the lemur was submitted to a second surgery , to which it did not survive. In this occasion internal organs  were collected. Macroscopic evaluation of organs revealed: thickening and hypertrophy of the intestinal wall; presence of whitish sclerotic areas on the liver surface. The other organs did not show gross lesions.The intestine sample collected at first surgery revealed heavy changes of the intestinal wall in the area of the ring inspissation. The luminal surface was widely ulcerated, the tonaca propria was completely absent. There was a massive degeneration of the submucosal tonaca and a strong and exuberant connective new growth as well as a partial destruction of the muscular tonaca. The intestinal wall was heavily compromised and showed an intense lymphoid infiltrate, displaying a multifocal round and dense pattern. Sometimes these lymphocyte aggregates were perivascular. The cellular infiltrate involved a hyperplastic reactive stroma, composed of immature connective tissue, strongly vascularized.

The lymphoid cells were morphologically homogeneous. The nuclei were small , euchromatinic,round plastic pots with polygonal shape, and often presented indented membrane. They contained multiple, medium sized nucleoli and chromatin aggregates. The cytoplasm tent to be diaphanous and slightly reticular. The mitotic index was high. At the edge of the ring-shaped lesion there was a peculiar inflammatory feature.Plasma cells and lymphocytes infiltration in the lamina propria; impressive villous atrophy and crypt hyperplasia with decreased villous height-to-crypt depth ratio; pronounced increase in the number of intraepithelial lymphocytes and Figure 3. The primary lesion was identified as media cells intestinal lymphoma associated with enteritis, and the peripheral inflammatory pattern was similar to that described in the case of grade 4 Marsh-Oberhuber human coeliac disease . In this occasion the main internal organs were collected and processed for histology. The macroscopic evaluation of organs revealed: thickening and hypertrophy of the intestinal wall; presence of whitish sclerotic areas on the liver surface. The other organs did not show gross lesions. The histological evaluation of the intestine Haematoxylin-Eosin sections collected at two different levels at necroscopy, pointed out inflammatory alterations similar to those observed at the edge of the neoplastic lesion found in the first intestinal sampling. Intestinal specimens collected at two different levels of the intestine were similar. The villi were strongly atrophic and flattened  and the mucosa assumed peculiar colonic-like features.

The epithelial cells showed a karyorectic multi-focal necrosis and intraepithelial lymphocytes were abundant. The tonaca propria displayed an intense lymphocyte/plasma cells infiltrate, as well as areas of necrosis. At the base of the muscularis mucosae a slight lymphocyte infiltration was detectable. The tunica muscularis and tunica serosa presented foci of lymphocyte infiltration. The histopathological data concerning the intestine could suggest the presence of a malabsorption related-enteritis similar to the human coelic disease . The intensity and the pattern of lymphocyte recruitment suggested the possible neoplastic progression of the lesion. The liver parenchyma presented an evident architecture destructuration of the lobules. Moreover, the lobules showed areas of multi-focal necrosis . Sometimes the necrotic areas were adjacent to the thickened Glisson membrane. An intense and diffuse infiltration of lymphoid cells was detectable, resembling those invading the tonaca propriaof the intestine. Associated to these features there were also evident areas of hemosiderin accumulation, considered as a common finding in zoo lemurs. Lung parenchyma presented a diffuse oedema associated to areas of destructive emphysema. The apical part of the lung revealed an area of acute pneumonia, with infiltration of neutrophilgranulocytes, involving the apical part of the lung. The spleen was morphologically intact but it was involved in the recruitment of a strong infiltrate composed by lymphoid cells similar to those observed in gut and liver.In order to identify the lineage of the neoplastic lymphocyte population and the inflammatory infiltrating lymphocytes, the histological sections were submitted to an immunoperoxidase based staining, using the following antibodies: polyc-lonal rabbit anti-human CD3 ; monoclonal mouse anti-human CD79α ; monoclonal mouse anti-human CD20 .

The CD3 antibody is specific for T cells and allows the immune detection of T lymphocytes derived neoplasms. The CD79α antibody is specific for B cells and allows the immune detection of neoplasms deriving from B lymphocytes at all stages of maturation. The CD20 antibody is specific for B cells precursors and mature B cells, excluding plasma cells. As positive controls, sections of human healthy lymph node, human skin characterized by lymphocyte infiltration and healthy lemur skin, were submitted to the same immuno histochemical procedure, using anti CD3, anti CD79α and anti CD20 as markers.In the intestine sections a relevant part of infiltrating lymphocytes  was immuno reactive for the T-lymphocyte marker CD3  and Figure 3, revealing inflammatory features. Also numerous IELs were positive and a slight positivity was found also in the marginal part of the Auerbach plexus . The B-lymphocyte marker CD20 did not identify positive cells among the infiltrating lymphocytes. Only few granular cells localized in the epithelium were positive. The anti CD79 antibody was ineffective on lemur healthy spleen  and due to this lack of cross-reactivity was not considered suitable to evaluate the immunophenotype of infiltrating cells. The intestine sections of the neoplastic lesion, when treated with the CD3 antibody, revealed the positivity of all the neoplastic lymphocytes, becoming more intense in the cells localized marginally to the main lesion. The CD20 antibody provided only a slight staining of some granular cells, as observed in the inflammatory lesions. The liver sections revealed a strong positivity of infiltrating cells to CD3, suggesting the presence of a T-lymphocyte population. IHC confirms the diagnosis of T-cells intestinal lymphoma and a peripheral coeliac-like enteritis.Few studies have been investigating lymphoma in primates and reports of this tumor in lemurs are extremely rare.

Findings from the current study are important as they provide useful information on lymphoma in the Lemur catta,highlighting an association between this tumor and coeliac disease. Basing on previous literature, humans with coeliac disease have been found to be at higher risk to develop small-bowel non-Hodgkin’s lymphoma. This study highlighted that similar association may exist also in lemurs, which are the most phylogenetically distant primates from our species. In particular, in human pathology enteropathy-type T-cell lymphoma is a recognized complication of gluten-sensitive enteropathy. Tumour cells probably derive from a subset of intraepithelial lymphocytes , as suggested by their ability to invade crypt epithelium. The routine application of immunohistochemical staining for lymphocyte markers such as CD3 has been proposed as a mean to better evaluate the number and distribution of IELs and the lymphocytes composing the lymphoma associated to the enteropathy. The immunophenotyping approach has been already proposed by Pye et al. in a lemur affected by intestinal lymphoma, resulting as a B cell  lymphoma enriched with a T cell  infiltrate. In our experience a relevant part of infiltrating lymphocytes in the intestine, most of the lymphocytes composing the intestinal neoplasm, and the liver lymphoid infiltrate, were immunoreactive for the T-lymphocyte marker CD3. These findings reinforce the diagnostic hypothesis proposed by the authors. In comparative terms, the role of dietary related disorders in captive lemurs should be considered as possible aetiology. Although the causative agent is still uncertain, a gluten-sensitive enteropathy should be considered. The possible sources of dietary gluten in captivity are biscuits, flours and other accidental foods. In 2005, although not allowed in the zoo, interactions between visitors and lemurs were frequent, due to the enclosure design. Although the lemur diet was made of fruits and vegetable and no gluten-food was provided, uncontrolled food items were given to the lemurs by the visitors. In 2010, all lemur groups were moved in a new area, in large naturalistic enclosure with no possibility for visitor-animal interactions.

Globally wheat  is cultivated to meet the consumable food demand of the humanity . Being a primary source of nutrition for millions of individuals, wheat contributes 30% of the total grain production of the world. However, annual yield gain in crop productivity is prolonged to meet the future demands for plant-based products for the projected global population in 2050 . Globally, different kinds of stresses are the main threats for production of crops . Plants are immobile, for their growth and for survival they need nutrients and water from the soil. Previously it has been reported that around 20% of the world cultivated area is being pretentious by salinity . Soil salinity adversely affects crop production up to 60%, and its drastic effect is more pronounced in the perspective of climate change scenario . Deposition of more salts in the upper layer of soil poses highly stressful environment for plant development, which ultimately causes reduction in yield or plant death . In Pakistan, salinity affected the 6.3  106 ha of irrigated land . This makes the circumstance disturbing and it represents a danger of deficiency of food. Recently, much consideration is given to wheat improvement by joining both new and traditional crop breeding approaches along with advances in management practices to cope with salinity problem . Improvement through conventional breeding requires the exploitation of the existing genetic variation in the wheat crop for salt tolerance. Past examinations  have uncovered large variation for salt resilience in wheat. Genetic diversity is also high in local and/or exotic material, hydroponic bucket which might be valuable for the improvement of salt-tolerance in future breeding plans. For this purpose, different methods were used which includes solution, sand, and pot cultures, saline raised beds, and field screening . Field evaluation may be sometime misleading or inaccurate as salinity intermingles with drought. In solution culture, supplements are promptly accessible to plant in differentiating with soil, where filtering or chelation of supplements to soil ruins their accessibility to plants. This strategy is reasonable due to the lower climatic variation , and it has been used by several researchers for genotype screening, especially under salinity .

Within the field evaluation, different elements  create problems inside the assurance of salt tolerant genotypes which are lenient in one climate may not be lenient in another climate . Additionally, soil features like pH, sodicity and harmful components i.e., boron change from zone to region indeed from land to land . Changing field and climates, genotype  climate associations should be analyzed cautiously for prevalent and trustworthy outcomes in salt affected regions. In wheat crop, root, shoot, and their biomass have moreover been detailed as principal characteristics which bestow salt resistance. Wheat researchers concluded that shoot biomass and plant biomass might be utilized for choice of salt-tolerant genotypes . Salt stress created a huge decrease in wheat plant biomass, and this decline was more clear at high levels of salt stress as compared to low levels . Since salt-tolerant genotypes had the option to hold their growth and had more biomass than the salt-susceptible ones. Increased biomass of resistant genotypes might be connected with their cap-potential to keep a preferable photosynthesis rate over the susceptible genotypes . In light of association and heritability, it transformed into presumed that lengths of root and shoot, their fresh and dry weights, have positive associations and high heritability, so these might be exceptionally gainful norms for settling on salt tolerant genotypes . Identification of hereditary variation is an essential of any breeding plan pointed toward creating salt-tolerant genotypes. This study was directed to portray the relationship of considered seedling parameters and to choose reasonable determination standards under both control and saline climates. The present study will provide novel breeding material to develop a salt tolerant genotype suitable for saline conditions.The current research was directed in the experimental area of University of Agriculture, Faisalabad , 31 260 N, 73 060 E, and 184.4 m above sea level .