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The research was conducted at the National Institute of Agricultural Sciences located in Mayabeque province, Cuba, with the aim of determining the response of bean crops to controlled deficit irrigation applied at different stages of their biological cycle. The study was carried out during two planting seasons (January and October 2021) under semi-controlled conditions. Seeds of the Triunfo 70 cultivar were sown in concrete containers, and three irrigation suspension periods of 15 days were studied: during the vegetative growth stage (VG), flowering stage (FS), and grain filling stage (GFS), along with a control group irrigated at 100% of the ETc. After the irrigation suspensions, soil moisture, growth indicators, and yield components were evaluated. In VG during the second experiment, it reduced stem length, leaf number, and leaf area. Above-ground dry mass decreased in both experiments, as well as the mass of 100 grains and grams per plant. In FS, it reduced stem length, relative chlorophyll content (RCC), mass of 100 grains, and yield in grams per plant, while in GFS, only the RCC was affected. Based on the results, it can be concluded that the grain filling stage was the least sensitive to water deficiency, causing the least impact on yield. [ABSTRACT FROM AUTHOR]

Due to water scarcity challenges, efficient management of irrigation water is becoming crucial. Water use efficiency (WUE) involves increasing crop productivity without increasing water consumption. This study was carried out to study the effect of hydrogel, deficit irrigation and soil type on WUE, soil hydro-physical properties and lettuce productivity. For this purpose, four irrigation treatments (100%, 85%, 70% and 60% of full irrigation requirements), four hydrogel concentrations (0, 0.1, 0.2 and 0.3% w/w) and three soil textural classes (clay, loamy sand, and sandy-clay soil) were conducted in pot experiment at open field during two consecutive seasons. The results revealed that crop growth parameters and soil hydro-physical properties were significantly affected by hydrogel application rates. Hydrogel addition significantly enhanced head fresh and dry weights, chlorophyll content, number of leaves and WUE. Application of hydrogel at 0.3% and 85% of irrigation requirements achieved the highest WUE without significant yield reductions. Changes in the studied hydro-physical properties of soil were more dependent on soil texture and hydrogel application rate than on the amount of irrigation water. The significant decrease in soil saturated hydraulic conductivity and bulk density confirms that super absorbent hydrogels could be recommended to improve soil water retention and enhance water use efficiency under deficit irrigation conditions. [ABSTRACT FROM AUTHOR]

Background: The increasing demand for food and feed necessitates the adoption of suitable crop production practices to enhance production while ensuring sustainability and conservation of scarce natural resources under the harsh environmental conditions in arid and semiarid regions. The mixed cropping of cereals and legumes is a critical component in sustainable agricultural system with improved forage yield. In addition, forage production with improved water use efficiency is vital in arid regions with limited irrigation water resources. The study investigated the combined effect of cereal-legume (barley-alfalfa) mixed cropping and deficit irrigation on the forage growth, dry matter yield and water productivity. Methods: The experiment was conducted at the KISR Station for Research and Innovation, Kuwait. Barley was mixed cropped with alfalfa in three different seed rate combinations (1:3, 1:1, 3:1) in addition to the sole cropping of component crops under three different irrigation regimes, corresponding to full irrigation (100% ET0) and two deficit irrigation (75% and 50% ETo of full irrigation) for two growing seasons (2017-2018 and 2018-2019). Result: The barley-alfalfa mixed cropping under deficit irrigation enhanced water productivity and dry matter yield under arid environmental conditions. The plant height, number of tillers per meter square, number of nodes, dry matter yield and water productivity were significantly affected by irrigation application rates. The mixed cropping of barley and alfalfa in 1:1 followed by 1:3 seed rate ratio and sole cropping of alfalfa under 75% irrigation revealed better performance in terms of dry matter yield and water productivity. [ABSTRACT FROM AUTHOR]

Drought is the most important factor limiting winter wheat yield in the North China Plain (NCP). Choosing high-yielding cultivars is an important measure to minimize the negative effects of drought stress. Field studies were conducted with 10 cultivars in the 2020–2022 seasons under three irrigation treatments (I0, without irrigation; I1, irrigated at jointing stage; I2, irrigated at jointing and anthesis stages) in the NCP to examine the water use strategies and root and shoot traits of high-yielding cultivars under different water supply conditions. The results showed that yield variation among cultivars was 21.2–24.6%, 23.7–25.9% and 11.6–15.3% for the I0, I1 and I2 treatments, respectively. Under water deficit conditions (I0 and I1), high-yielding cultivars reduced water use during vegetative stages and increased soil water use during reproductive stages, especially water use from deeper soil layers. Those cultivars with higher root length density (RLD) in deep soil layers exhibited higher water uptake. Each additional millimeter of water used after anthesis from the 100–200 cm soil layers increased grain yield by 23.6–29.6 kg/ha and 16.4–28.5 kg/ha under I0 and I1, respectively. This water use strategy enhanced dry matter accumulation after anthesis, decreased canopy temperature (CT) and increased relative leaf water contents (RLWC), which ultimately improved grain yield. For winter wheat grown under I2, cultivars that decreased water use after anthesis had higher water productivity (WP). Root length (RL), root weight (RW) and root:shoot ratio were each negatively correlated with grain yield, while above-ground biomass was positively correlated with grain yield. Therefore, higher dry matter accumulation and smaller root systems are two important traits of high-yielding cultivars under sufficient water supply conditions (I2) in the NCP. [ABSTRACT FROM AUTHOR]

Due to the influence of the Asian southwest monsoon, seasonal drought is serious and water resources are scarce in the Yunnan province of Southwest China. More effective water-saving irrigation methods should be developed to solve the problem of water scarcity in the dry season. In this study, a subsurface drip irrigation method was used to improve the water productivity of tomato cultivation. Deficit irrigation was conducted. We controlled the lower limit of soil moisture at three different levels (55~65%, 65~75%, and 75~85% of the field capacity). The results indicated that the subsurface drip irrigation treatment significantly increased tomato height in the later stage of tomato growth. Due to the buried pipes, the root/shoot ratio was 8~18% higher for subsurface drip irrigation than for surface drip irrigation methods. Though the yields using subsurface drip irrigation methods were slightly lower than those obtained using surface drip irrigation methods, the tomato quality and water productivity improved significantly. The subsurface drip irrigation methods improved the water productivity by 8.5~21.8% at different soil moisture levels and improved the chlorophyll content by 9.1~17.3%. The VC, soluble sugar, soluble solids, and the ratio of sugar to acid increased by 6.5~15.2%, 7.3~21.6%, 4.1~6.6%, and 3.2~20.8%. This study also indicated that by optimizing the irrigation methods and patterns, water productivity and fruit quality could be improved by more than 50%. This research will be helpful for guiding irrigation during the drought season in the southwest monsoon area in Asia. [ABSTRACT FROM AUTHOR]

Clay‐rich rocks are integral to subduction zone dynamics and of practical importance, for example, as barriers in nuclear waste and CO2 repositories. While the effects of swelling strain on the self‐sealing capabilities of these rocks are relatively well‐established, the implications of polar fluids interacting with charged clay particles on the frictional behavior, and the role of swelling stress in initiating slip in critically stressed faults, remain ambiguous. To address these uncertainties, we conducted triaxial friction experiments using saw‐cut samples, with the upper half composed of Opalinus claystone (OPA) and the lower half of Berea sandstone (BER). The frictional strength of the non‐wetted OPA‐BER interface was estimated based on experiments at confining pressures of 4–25 MPa and constant axial loading rate (0.1 mm/min). Fluid injection friction experiments were performed using decane (non‐polar fluid) or deionized water (polar fluid) at 10 and 25 MPa confining pressures and constant piston displacement control. Macroscopic mechanical data were complemented by distributed strain sensing on the sample surface. Compared to decane, the frictional strength of the OPA‐BER interface tended to decrease when injecting water, which is attributed to phyllosilicate lubrication and the transition of the OPA from a solid rock to an incohesive mud near the saw‐cut surface. When injecting water, slip was initiated during initial hydration of the OPA‐BER interface, although the apparent stress state was below the yield stress. To explain this behavior, we propose that the swelling stress is a crucial factor that should be integrated into the effective stress model. Plain Language Summary: Clay‐rich rocks are important in subduction zones and for practical applications like nuclear waste containment and CO2 storage. A unique property of clay is the ability to swell by incorporation of water. If swelling deformation is constrained, swelling stress can develop. While the enhanced sealing ability of fractures due to swelling is well‐known, the effect of water‐clay interactions on friction and the contribution of swelling stress to fault reactivation remain unclear. We studied these effects with laboratory experiments where Opalinus claystone (OPA) was sheared against Berea sandstone. First, using experiments without fluids, we established that our set‐up is representative for claystones. In further experiments, we injected a non‐polar fluid that does not interact with clay. We compared these with experiments where we injected water, which is polar and therefore interacts with the charged clay. The frictional strength tended to decrease when injecting water, likely due to water acting as a lubricant and transforming OPA into a slurry. Surprisingly, movement along the interface started although the applied stress was below the threshold. We explain this by the contribution of swelling stress to the overall stress state. These findings improve our understanding of clay‐rich rock behavior in nature and practical applications. Key Points: The frictional strength of clay‐rich rocks tends to decrease in the presence of a polar fluid compared to a non‐polar fluid or no fluidFrictional slip in clay‐rich rocks may be initiated although the apparent effective stress state is below the yield stressH2O‐clay interactions may contribute to reactivation of faults by altering the mechanical properties and the build‐up of swelling stresses [ABSTRACT FROM AUTHOR]

Response of 20 genotypes of sorghum to both full irrigation (100% ET) and deficit irrigation (60% ET) which were evaluated to identify water stress effects on yield and its attributes. The field experiments were conducted in Assiut Research Station, Assiut Governorate, Egypt, during 2021 and 2022 growing seasons. Two experiments were practiced separately under normal irrigation and water stress conditions. The combined analysis of variance for 20 genotypes across two years under two locations (normal (100% ET) and stress (60% ET) revealed highly significant differences among genotypes for all studied traits. Moreover, the genotypes × irrigation interaction variance was also highly significant or significant for all the studied traits except for panicle length. The highest means value for 1000-kernel weight across two years under two treatments (27.33 g) was given by EXO-27 genotype and for grain yield (24.20 ard. /fed.) by EXO-27. Ten and twelve of genotypes in 2021 and 2022 respectively, gave drought susceptibility indexes less than one, indicating less susceptibility. Under stress a positive and highly significant correlation was found between number of green leaves plant-1 and each of panicle width and panicle length (0.612, 0.427, respectively). On the other hand, there are negative and significant correlations (-0.375) between 50% flowering and grain yield under normal irrigation. [ABSTRACT FROM AUTHOR]

Egypt suffers from limited water resources, which threatens food security and reduces the chances of horizontal expansion by reclaiming new desert lands. Therefore, it was necessary to achieve this target for the productivity and quality of crops under harsh conditions. Field experiments proceeded at the Nubaria research station under sandy soil conditions to evaluate the effects of different silicon sources (silica gel, algae rich in silicon, and potassium silicate) on sugar beet yield and quality under different irrigation regimes (100%, 75%, and 50%) of water requirement (WR) during the growing seasons of 2020 and 2021. Results showed that potassium silicate was most effective for increasing chlorophyll content and growth parameters compared with other sources under water stress conditions. Also, improved nutrient contents in the root and shoot of sugar beet gave the highest values on N (0.58%, 2.54%), P (0.132%, 0.318%), K (0.42%, 1.05%), Fe (67.18, 83.28 ppm), and Zn (11.29, 12.73 ppm) content, respectively, when applied with K2SiO3 compared with deficit irrigation conditions. Stimulating rich-Si remains the most effective for enhancing the growth, quality, and yield of sugar beet grown under deficit irrigation regimes, which makes plants more resistant to weather conditions and water stress. [ABSTRACT FROM AUTHOR]

Seedling emergence and stand establishment of carrot seeds are often slow and erratic which results in low productivity. Poor seed quality together with lack of pre­sowing seed treatments and improper irrigation management can be mentioned as the major factors that influence the yield and productivity of carrot. The present study was carried out with the objective to evaluate the effects of different seed priming techniques on early seedling establishment, growth and yield of carrot (Daucus carota L. cultivated variety Nantes) exposed to different irrigation intervals, under field conditions at Gerado, South Wollo, Ethiopia. Four seed priming treatments (no priming, hydro priming, halo priming and hormonal priming) and three irrigation intervals (4, 7 and 10 days) were combined as factorial RCBD in split plot arrangement with three replications. The irrigation intervals were assigned to main plots and the seed priming techniques to sub plots. Result indicated that the interaction effects of priming techniques and irrigation intervals significantly affected the phenological and yield parameters. Distilled water treatment in seven and ten days irrigation interval recorded the highest marketable carrot root yields of 33.73 t h­-1 and 30.63 t h-­1, respectively. Hence, hydro priming and seven days irrigation interval can be recommended for the production of carrot in the study area and similar agro­ecologies. Given the promising results obtained, further repetitions of the study are recommended to validate the use of these techniques in further locations and in different seasons. [ABSTRACT FROM AUTHOR]

Virtual water trade (VWT) provides a new perspective for alleviating water crisis and has thus attracted widespread attention. However, the heterogeneity of virtual water trade inside and outside the river basin and its influencing factors remains further study. In this study, for better investigating the pattern and heterogeneity of virtual water trade inside and outside provincial regions along the Yellow River Basin in 2015 using the input-output model (MRIO), we proposed two new concepts, i.e., virtual water surplus and virtual water deficit, and then used the Logarithmic Mean Divisia Index (LMDI) model to identify the inherent mechanism of the imbalance of virtual water trade between provincial regions along the Yellow River Basin and the other four regions in China. The results show that: 1) in provincial regions along the Yellow River Basin, the less developed the economy was, the larger the contribution of the agricultural sector in virtual water trade, while the smaller the contribution of the industrial sector. 2) Due to the large output of agricultural products, the upstream and midstream provincial regions of the Yellow River Basin had a virtual water surplus, with a net outflow of virtual water of 2.7 × 108 m3 and 0.9 × 108 m3, respectively. 3) provincial regions along the Yellow River Basin were in a virtual water deficit with the rest of China, and the decisive factor was the active degree of trade with the outside. This study would be beneficial to illuminate the trade-related water use issues in provincial regions along the Yellow River Basin, which has far-reaching practical significance for alleviating water scarcity. [ABSTRACT FROM AUTHOR]

One of the alternative methods for managing irrigation water is deficit irrigation, particularly alternate furrow irrigation (AFI). This deficit in irrigation is affected by uncontrolled rainfall. In line with this, rainfall uncertainty causes a variation between the measured actual crop evapotranspiration and the theoretical crop evapotranspiration. Let us imagine that rain falls during the deficit irrigation research, and the soil moisture under the deficit experiment is then raised to the soil field capacity. It is incorrect to report the result as a deficit. Thus, there is a research gap on the effect of rainfall uncertainty on the quantity of theoretical and actual crop evapotranspiration under deficit irrigation. This study was carried out at the Arba Minch University demonstration site on onion crops. Using CROPWAT 8.0 software, the reference evapotranspiration (ETo) was calculated using the Penman-Monteith formula. The crop coefficient and ETo were used to calculate the theoretical crop evapotranspiration. In contrast, actual crop evapotranspiration was calculated using soil moisture measurements before and after each irrigation event after applying theoretical crop evapotranspiration. As a result, there is a significant difference between the calculated theoretical crop evapotranspiration and actual crop evapotranspiration from a deficit study. Thus, the calculated seasonal theoretical crop evapotranspiration was 201.72 mm. On the other hand, the actual crop evapotranspiration was 275.82 mm. This revealed that the actual crop evapotranspiration was greater than the calculated theoretical crop evapotranspiration by 36.7%. Uncontrolled rainfall was identified as the output's cause. This has an evident effect on the deficit in experimental research. Hence, conducting the deficit experiment in a greenhouse is more reasonable. In addition, it is possible to assess actual crop evapotranspiration based on daily soil moisture measurements and report the deficit level based on the measured amount. [ABSTRACT FROM AUTHOR]

Citrus orchards in semi-arid regions are increasingly exposed to drought conditions due to climate change. This study compared the physiological and growth responses of 'W. Murcott' tangor (WM) grafted onto Citrus macrophylla (M), Swingle citrumelo (SC), C-35 citrange (C35), or bitter citrandarin (C22) rootstock subjected to two irrigation treatments: daily irrigation to replace 100% of the water lost daily by evapotranspiration (ET; control treatment) or daily irrigation to replace 75% of the water lost daily by ET (water deficit treatment). For trees in each treatment, leaf gas exchange, relative chlorophyll content, chlorophyll fluorescence, midday stem water potential, trunk cross-sectional area, and shoot length were measured 46 days after treatments were initiated. The results showed that WM on SC or C22 rootstock exhibited isohydric behavior, where decreased stomatal conductance limited transpiration in the water deficit treatment. WM on M rootstock exhibited an anisohydric response in the water deficit treatment, where there was no stomatal control of water loss by transpiration. Among the rootstocks tested for WM, the most tolerant to soil water deficit was SC, whereas trees on M rootstock were the most negatively affected by soil water deficit. [ABSTRACT FROM AUTHOR]

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The changing climate makes it more difficult to manage water resources and food production sustainably. Various adaptation measures have been proposed to moderate the negative impacts of climate change; however, implementation of these measures may be hampered by other factors even if the benefits are acknowledged—a situation termed "soft adaptation limits" by the IPCC. We hypothesized that societal rules can be a potential barrier to adaptive action if they are too fixed, because such rules have coevolved with the interactions between the past climate and human activities. To test this hypothesis, we present a framework based on the assumption that associated societal rules of Japan's matured irrigation systems are potential barriers to adaptation. The framework consisted of two process‐based models, one to evaluate the water deficit risk and one to evaluate the benefits of optimizing rice yield and quality. We applied each model to an experiment in which we shifted the current transplantation date by 1 week for up to 5 weeks before and after the current date under the historical (1981–2000) and RCP 2.6 and 8.5 (2011–2030 and 2031–2050) scenarios. We revealed two contrasting development pathways in the study watershed. Soft adaptation limits imposed by water availability will occur by 2030 if farmers optimize for quality, whereas mutual benefits to farmers and river administrators will be achieved if farmers seek yield. We argue that more participatory research with stakeholder engagement, as well as policy discussions about these possible developments, is needed to ensure successful adaptation. Key Points: We present a framework for examining whether societal rules of Japan's matured irrigation systems are potential barriers to adaptationWe show that potential barriers to adaptation imposed by water availability will occur if farmers optimize for rice qualityWe argue that more participatory research with stakeholder engagement is needed to ensure successful adaptation [ABSTRACT FROM AUTHOR]

Context: Exogenous use of potential organic compounds through different modes is a promising strategy for the induction of water stress tolerance in crop plants for better yield. Aims: The present study aimed to explore the potential role of alpha-lipoic acid (ALA) in inducing water stress tolerance in mungbean lines when applied exogenously through various modes. Methods: The experiment was conducted in a field with a split-plot arrangement, having three replicates for each treatment. Two irrigation regimes, including normal and reduced irrigation, were applied. The plants allocated to reduced irrigation were watered only at the reproductive stage. Three levels of ALA (0, 0.1, 0.15 mM) were applied through different modes (seed priming, foliar or priming+foliar). Key results: ALA treatment through different modes manifested higher growth under reduced irrigation (water stress) and normal irrigation. Compared to the other two modes, the application of ALA as seed priming was found more effective in ameliorating the adverse impacts of water stress on growth and yield associated with their better content of leaf photosynthetic pigments, maintenance of plant water relations, levels of non-enzymatic antioxidants, improved activities of enzymatic antioxidants, and decreased lipid peroxidation and H2O2 levels. The maximum increase in shoot fresh weight (29% and 28%), shoot dry weight (27% and 24%), 100- grain weight (24% and 23%) and total grain yield (20% and 21%) in water-stressed mungbean plants of line 16003 and 16004, respectively, was recorded due to ALA seed priming than other modes of applications. Conclusions: Conclusively, 0.1 and 0.15 mM levels of ALA as seed priming were found to reduce the adverse impact of water stress on mungbean yield that was associated with improved physio-biochemical mechanisms. Implications: The findings of the study will be helpful for the agriculturalists working in arid and semi-arid regions to obtain a better yield of mungbean that will be helpful to fulfill the food demand in those areas to some extent. [ABSTRACT FROM AUTHOR]

Reservoir is a vital tool for human utilization of water resources, and the deterioration of its water quality can seriously threaten the water cycle and sustainable urban development. However, there are relatively few studies in academia that analyse and evaluate the water quality of multiple reservoirs at the same time. To address this knowledge deficit, we collected 108 water samples from three different reservoirs in Chuzhou City for 36 months (from 2019 to 2021), explored the drivers of changes in water quality parameters over time and the extent of eutrophication. Our results indicated that the water quality of the reservoirs was deteriorating during the study period, among which Huanglishu Reservoir and Shahe Reservoir reached mild eutrophic status, and both had higher eutrophication levels than Chengxi Reservoir. Secchi depth, total nitrogen and total phosphorus were the principal factors inducing eutrophication. The biassed utilization of reservoir functions was the major contributor to the discrepancy in the degree of eutrophication. Furthermore, Pearson correlation analysis revealed that there are significant correlations between many water quality parameters. Cluster analysis grouped the 12 months of each year into three clusters (stable water level period, rainy season high flow period and winter low flow period). Based on this, analysis of variance showed that most water quality parameters varied considerably between the clusters. Collectively, this study identified the actual water quality conditions of three reservoirs in Chuzhou City and provided guidance for local water quality management and environmental protection. [ABSTRACT FROM AUTHOR]

IN EGYPT, water scarcity is the main problem the agricultural sector faces. Salicylic acid (SA) as a plant growth regulator may help mitigate the adverse effects of deficit irrigation water on pepper plants. Sweet pepper (cv. S702 F1) plants subjected to deficit irrigation (DI40%= 60% of crop evapotranspiration, ETc) regularly during growth stages produced decreases in plant height, total chlorophyll, fruit number per plant, fruit length, fruit diameter, fruit volume, fruit yield, fruit carotenoids, and total dry matter comparing with the full irrigation (FI= 100% of ETc). However, water use efficiency (WUE), proline, free amino acids, ascorbic acid, total sugars, total soluble solids (TSS), total phenols content (TPC), total flavonoids content (TFC), and nitrate content were enhanced under deficit irrigation conditions. The results showed that under FI or DI40% with foliar application of SA at 1.0 mM was more effective than 0.5 and 1.5 mM in improving vegetative growth and yield parameters. However, FI produced the highest significant values of plant height, total chlorophyll, fruit yield, carotenoids, and total dry matter. Conversely, the pepper plant's ability to withstand DI40% was enhanced by the 1.0 mM SA treatment, which resulted in the highest accumulation of ascorbic acid, total sugars, TSS, TPC, and TFC. Moreover, the application of SA significantly increased WUE and decreased fruit nitrate content. It could be concluded that the foliar application of SA can alleviate the detrimental effects of deficit irrigation on pepper plants. [ABSTRACT FROM AUTHOR]

The conservation of water and its rational management in crop irrigation is important for sustainable agriculture in arid and semi-arid regions, particularly with the appearance of the effects of climate change in these regions. The paper reports a study of the impact of using water from fish farming in the irrigation of pepper crops grown in greenhouses under salinity conditions. The results obtained show that the use of fish water in irrigation improves the vegetative growth of plants and their fruit yields. It also has a beneficial effect on the soil by increasing its level of organic matter, total Nitrogen and other nutrients. The value that this work adds is the conservation of the soil by improving its quality and the reduction of water pollution by reusing this wastewater in irrigation. The reduced use of synthetic fertilisers facilitates the application of organic farming. These advantages benefit the environment and consumers of the crops. [ABSTRACT FROM AUTHOR]

In regions where water is a limited resource, lettuce production can be challenging. To address this, water management strategies like deficit irrigation are used to improve water-use efficiency in agriculture. Associating this strategy with silicon (Si) application could help maintain adequate levels of agricultural production even with limited water availability. Two lettuce crop cycles were conducted in a completely randomized design, with a factorial scheme (2 × 3), with three irrigation levels (60%, 80% and 100%) of crop evapotranspiration (ETc), and with and without Si application. To explore their combined effects, morphological, productive, physiological and nutritional parameters were evaluated in the crops. The results showed that deficit irrigation and Si application had a positive interaction: lettuce yield of the treatment with 80% ETc + Si was statistically similar to 100% ETc without Si in the first cycle, and the treatment with 60% ETc + Si was similar to 100% ETc without Si in the second cycle. Photosynthetic rate, stomatal conductance, intercellular CO2 concentration, transpiration rate and total chlorophyll content increased under water-stress conditions with Si application; in the first cycle, the treatment with 80% ETc + Si increased by 30.1%, 31.3%, 7.8%, 28.46% and 50.3% compared to the same treatment without Si, respectively. Si application in conditions of water deficit was also beneficial to obtain a cooler canopy temperature and leaves with higher relative water content. In conclusion, we found that Si applications attenuate water deficit effects and provide a strategy to ameliorate the yield and water productivity in lettuce crops, contributing to more sustainable practices in agriculture. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate different L. corniculatus L. ecotypes under water-deficit conditions to identify changes in relative water content and photosynthetic pigments as indicators of physiological responses during different years' seasons. The experiment was conducted in a randomized block design with three replicates. Ten treatments were performed as a factorial of 2 × 5, where the first variation factor was the soil water content—no water deficit (NDW) with 100% field capacity (FC), and water deficit (DW) corresponding to 85.4% of the FC—and the second variation factor comprised four ecotypes and one variety of L. corniculatus. A significant effect was identified on the concentration of photosynthetic pigments, mainly total chlorophyll, with chlorophyll a in the 255301 ecotype with records of 187.8, 167.5, and 194.6 mg g−1 FW in WD, corresponding to an increase of 86.0%, 172.6%, and 16.6%, respectively, in relation the lower values obtained in the ecotype 202700 under NWD. In carotenoids, higher concentrations were observed in the 255301 and 202700 ecotypes and the Estanzuela Ganador variety under WD in most seasonal periods, except summer; a similar response was found in the 202700 ecotype and the Estanzuela Ganador variety during the winter season, also in WD. The results showed that the first two principal components accounted for 71.8% of the total variation, with PC1 representing chlorophyll a, chlorophyll b, and total chlorophyll, and PC2 representing carotenoids, temperature, relative chlorophyll index, and relative water content. The observations were grouped based on soil moisture content, with the optimal moisture group exhibiting higher chlorophyll and carotenoid concentrations. The findings suggest that soil moisture content significantly affects the performance of L. corniculatus ecotypes, and the plant shows seasonal variations in response to water-deficit conditions. This research contributes to understanding the physiological responses of L. corniculatus and its potential as a water-efficient forage crop for promoting sustainable agriculture and enhancing food security. [ABSTRACT FROM AUTHOR]

This document is an editorial that discusses the risks of climate change on agricultural productivity in Sub-Saharan Africa and the importance of water-smart crop farming as an adaptation strategy. It highlights various technologies and approaches, such as irrigation and crop diversification, and provides summaries of two related articles. The research aims to contribute to knowledge on water-smart farming systems in Sub-Saharan Africa and promote sustainable crop production. The document also includes a comprehensive list of references for library patrons conducting research on various topics in agriculture and water management. [Extracted from the article]

This document discusses the importance of water in agricultural production and the relationship between agriculture and water use. It highlights the increase in land used for irrigation and the need for sustainable agricultural practices to address environmental challenges. The document also provides an overview of a special issue on agricultural practices to improve irrigation sustainability, including studies on soil quality, management techniques, and agroecosystem sustainability. The selected articles cover a range of topics and offer valuable insights into irrigation sustainability in different regions and contexts. The document concludes by emphasizing the interdisciplinary nature of irrigation sustainability and the need for further research in this area. [Extracted from the article]

In the face of the climate change crisis, the increase in air temperature negatively impacts rice crop productivity due to stress from water scarcity. The objective of this study was to determine the rice crop water stress index (CWSI) and stomatal conductance (Gs) under different irrigation regimes, specifically continuous flood irrigation treatments (CF) and irrigations with alternating wetting and drying (AWD) at water levels of 5 cm, 10 cm, and 20 cm below the soil surface ( AWD 5 ,   AWD 10 , and AWD 20 ) in an experimental area of INIA-Vista Florida and in six commercial areas of the Lambayeque region using thermal images captured with thermal sensors. The results indicated that AWD irrigation generated more water stress, with CWSI values between 0.4 and 1.0. Despite this, the yields were similar in CF and AWD 20.   In the commercial areas, CWSI values between 0.38 and 0.51 were obtained, with Santa Julia having the highest values. Furthermore, a strong Pearson correlation (R) of 0.91 was established between the CWSI and Gs, representing a reference scale based on Gs values for evaluating water stress levels. [ABSTRACT FROM AUTHOR]

The development of management plans which lead to water efficient landscapes is a growing need in the turfgrass community. While deficit irrigation as a scheduling method can improve water conservation, more information is desired on how to best leverage other management practices, such as mowing height when deficit irrigation is imposed. The objectives of this study were to characterize actual evapotranspiration (ETa), turfgrass visual quality, clipping production, and root development of 'TifTuf' bermudagrass (Cynodon dactylon × C. transvaalensis Burt Davy) when irrigated at full (1.0 × ETa) and deficit levels (0.65 and 0.30 × ETa), and cut at four separate mowing heights (2.5, 5.0, 7.5, and 10.0 cm) over two 8-week experimental runs. An elevated ETa was observed at the 7.5 cm and 10.0 cm mowing heights compared to the 2.5 cm mowing height in both runs, and the 5.0 cm mowing height in one run. The visual quality decreased throughout both study periods and mostly for the deficit irrigation treatments, with visual quality falling below minimum acceptable levels at the lowest irrigation level (0.30 × ETa) 5 weeks into run A, and 8 weeks into run B. Despite an elevated ETa and a higher root dry weight at higher mowing heights (7.5 and 10.0 cm), clipping production and visual quality was generally higher at lower mowing heights (2.5 and 5.0 cm) for both full and deficit irrigation levels. These results demonstrate that mowing height can significantly influence bermudagrass water use, as well as responses to deficit irrigation. When maintaining 'TifTuf' bermudagrass at heights above 2.5 cm, the results from this study indicate a lower water use and improved response to deficit irrigation at mowing heights ≤ 5 cm. [ABSTRACT FROM AUTHOR]

Irrigation and nitrogen management are crucial for sustainable potato (Solanum tuberosum L.) production. A field experiment was conducted during the 2022 and 2023 growing seasons at Farmington, New Mexico, to evaluate the performance of two chip potato varieties (Lamoka and Waneta) under three irrigation regimes (full irrigation (FI), 20% deficit irrigation (DI) and 40% DI) and seven nitrogen fertilizer rates (0, 60, 115, 170, 220, 280, and 340 kg N/ha). The treatment combinations of irrigation regimes, nitrogen rates, and varieties were arranged in a split–split plot design with three replications as main plot, sub-plot, and sub-sub plot, respectively. The two-year results showed that irrigation regimes had the most significant effect on plant growth, physiology, and tuber yield of the potato varieties. For both Lamoka and Waneta, the plant height and canopy cover were lower under 40% DI than under 20% DI and FI treatments. The SPAD meter values were higher under 40% DI, followed by 20% DI and FI treatments, whereas the stomatal conductance was higher under FI, followed by 20% DI and 40% DI during both growing seasons. Regardless of nitrogen rates and variety, a 20% water-saving irrigation strategy reduced the total tuber yield by 4.5% and 22.1% in the 2022 and 2023 growing seasons, respectively, while the 40% water-saving irrigation strategy reduced total tuber yield by 36.8% and 58.2% in the 2022 and 2023 growing seasons, respectively, as compared to full irrigation. Shifting from full irrigation to 20% DI could save 711.2 to 1036.3 m3/ha of irrigation water. For Lamoka, the highest total tuber yield was obtained with 60 kg N/ha under 20% DI and 220 kg N/ha under FI in 2022 and 2023, respectively. For Waneta, the highest total tuber yield was obtained with 115 kg N/ha under 20% DI and 170 kg N/ha under FI in 2022 and 2023, respectively. Maximum water use efficiency (WUE) was obtained at 60 kg N/ha with 20% DI for both Lamoka and Waneta in 2022, while maximum WUE was obtained at 220 kg N/ha under FI for Lamoka and at 170 kg N/ha for Waneta in the 2023 season. The maximum nitrogen use efficiency (NUE) was achieved with 60 kg N/ha under 20% DI for both varieties during both growing seasons. Thus, for sustainable irrigation and nitrogen management, the application of a 20% deficit irrigation strategy with a lower nitrogen rate (60 to 170 kg N/ha) could be the best option to improve WUE and NUE with minimal tuber yield reduction. Our study suggested that 40% deficit irrigation would not be beneficial as compared to both full irrigation and 20% water-saving irrigation. [ABSTRACT FROM AUTHOR]

The tomato is a vital component of agriculture and is the second-most important vegetable globally. Maintaining a high tomato production requires both water quality and quantity. Water-scarce regions like Saudi Arabia still lack an understanding of the impact of deficit irrigation and the use of a blend of saline and freshwater, especially their nuanced impact across growth stages. The purpose of this study was to evaluate the effects of six different irrigation amounts: full irrigation with 100% ETc (FI), regulated deficit irrigation with 60% ETc (DI), and deficit irrigation with 60% ETc, except for the initial (DI-int), development (DI-dev), mid-season (DI-mid), and late-season (DI-lat) stages. This was performed with three different water qualities: fresh (FW), saline (SW), and fresh-saline blend (1:1) (MW) water. FW and MW enhanced the growth, physiology, morphology, yield, and quality, while SW had the lowest values. DI reduced these parameters and lowered yields by 13.7%, significantly improving water use efficiency (WUE) by 44% and fruit quality. DI-mid or DI-lat slightly improved yields while remarkably decreasing WUE and fruit quality. DI outperforms deficit irrigation in all growth stages except one, and countries with limited freshwater resources can benefit from a mix of fresh and saline water with a 60% ETc deficit irrigation, resulting in greater water savings. [ABSTRACT FROM AUTHOR]

This study examined the performance of random forest (RF), support vector machine (SVM) and adaptive boosting (AB) machine learning models used to estimate daily potato crop evapotranspiration adjusted (ETc-adj) under full irrigation (I100), 50% of full irrigation supply (I50) and rainfed cultivation (I0). Five scenarios of weather, crop and soil data availability were considered: (S1) reference evapotranspiration and precipitation, (S2) S1 and crop coefficient, (S3) S2, the fraction of total available water and root depth, (S4) S2 and total soil available water, and (S5) S3 and total soil available water. The performance of machine learning models was compared with the standard FAO56 calculation procedure. The most accurate ETc-adj estimates were observed with AB4 for I100, RF3 for I50 and AB5 for I0 with coefficients of determination (R2) of 0.992, 0.816 and 0.922, slopes of 1.004, 0.999 and 0.972, modelling efficiencies (EF) of 0.992, 0.815 and 0.917, mean absolute errors (MAE) of 0.125, 0.405 and 0.241 mm day−1, root mean square errors (RMSE) of 0.171, 0.579 and 0.359 mm day−1 and mean squared errors (MSE) of 0.029, 0.335 and 0.129 mm day−1, respectively. The AB model is suggested for ETc-adj prediction under I100 and I0 conditions, while the RF model is recommended under the I50 condition. [ABSTRACT FROM AUTHOR]

Background: Despite drought and nitrogen (N) deficit being two of the most important crops' growth limiting factors, only few studies have explored tomato phenotypic variability in response to both abiotic stresses. Aims: In this study, we aimed to perform a phenotypic evaluation and an analysis of the growth traits of 40 tomato genotypes (mostly focusing on old cultivars, but also including modern hybrids and wild tomato relatives' accessions as anchors) grown in pots that were subjected to combined N and water deficit. Methods: Each genotype was divided into two groups: control (100% N, 100% field capacity) and combined deficit (20% N, 50% field capacity). A total of 14 morpho-physiological traits were evaluated and further analyzed using multivariate statistical methods. Results: The Principal Component Analyses revealed considerable phenotypical diversity among tomato genotypes, with four principal components explaining 82% of the variability. Data integration on a cluster analysis separated the studied genotypes into three distinct clusters based on their ability to handle the combined deficit. Tolerance was associated with traits such as lower specific leaf area, lower leaf area ratio and higher water use efficiency, comparing to the sensitive genotypes. Conclusions: This study shows that tomato tolerance to combined N and water deficit largely varies between genotypes and that old cultivars represent a valuable gene pool towards more sustainable food production systems. [ABSTRACT FROM AUTHOR]

To increase the agricultural profit, an experiment was conducted at the Scientific Agricultural Research Center (SARC) at Salamiyah, Syria. The experiment aimed to estimate the optimum irrigation level that maximizes productivity as well as the black cumin's quality local quality standards under experimental conditions. The irrigation treatments were 25, 50, 75 and 100% of the Potential Evapotranspiration (ETP) based on Class-A pan evaporation. The treatments were denoted as B, C, D and E, respectively. The no-irrigation treatment (A) was considered as control. Irrigation water was applied by a drip system. The A-E treatments were designed and implemented using complete randomized block design (CRBD) with four replications. The actual Evapotranspiration (ETa) was calculated after calibration of soil using SPAW software. Furthermore, crop yield, Irrigation Water Use Efficiency (IWUE), yield response factor (ky) and some parameters (period of growth stage, date of flowering...etc.) were studied during 2018-2019 successive growth seasons. Results showed that irrigation could be scheduled using some equations and Class-A pan evaporation. Moreover, the vegetative growth parameters flourished virtually and significantly by comparing higher and lower irrigation levels. However, Irrigation Water Use Efficiency (IWUE) values increased by reducing the applied irrigation water. Treatment B recorded the highest IWUE value (2.4 kg ha-1 mm-1), but key values remained less than 1.0, indicating that the plant tolerates drought. Furthermore, treatment C scored the top-seed (130.6%) concerning the profit/total costs ratio. Finally, based on the results, we recommend that irrigation should not be more than 75% and not less than 25% of the ETP. [ABSTRACT FROM AUTHOR]

Increasing N use efficiency (NUE) is desirable in turfgrass management. Traditional definition of NUE in turfgrass is essentially the inverse of nitrogen concentration in the clippings and is often evaluated once in a growing season. In this experiment, we followed the Brenderse and Aerts' definition of NUE as the product of mean residence time (MRT) and nitrogen productivity (NP). The objective of this experiment was to identify NP changes over time in Kentucky bluegrass cultivars at different N levels under deficit irrigation. Nine Kentucky bluegrass (Poa pratensis L.) and two hybrid bluegrass cultivars from 10 phenotypic classes were tested under N rates of 10 and 40 g m−2. Deficit irrigation at 60% of the evapotranspiration was imposed. The results showed interaction effects on NP from N level, irrigation, and cultivar. Low‐N treatment resulted in higher NP values as compared to high‐N for 'Merit' and 'Martha'. No NP difference existed between N or irrigation levels for 'Blue ghost', 'Geronimo', 'Heidi', 'Bandera', 'Impact', 'Fielder', 'Jackrabbit', and 'Park'. 'Rhythm' showed lower NP values in high‐N combined with full irrigation compared to other treatments. In general, increasing N levels resulted in lower NP, but higher nitrate reductase activity (NaR) and higher net photosynthesis. No N by irrigation interaction effect was detected for effective quantum yield or NaR. In conclusion, leaf‐level NP was shown to be an effective parameter for in‐season monitoring of the above‐ground NUE of Kentucky bluegrass, which provided more dynamic information than clipping yields or a one‐time NUE calculation based on traditional definition. [ABSTRACT FROM AUTHOR]

This research was carried out in Sarvestan city of Fars province in the southwest of Iran. Due to successive droughts, the groundwater resources of this city have decreased in terms of quantity and quality. Therefore, deficit irrigation in this area is inevitable and occurs mainly by increasing the irrigation cycle in pistachio orchards. Hence, a study was conducted in a pistachio orchard of Ahmad Aghaei cultivar in Sarvestan city during 2018-2020 with the aim of comparing irrigation water productivity, crop yield and machine farm efficiency in different water distribution substrates in the surface irrigation method with constant irrigation cycle. The experimental design was performed in the form of randomized complete blocks with 4 treatments of irrigation management in three replications. The treatments were: conventional flooding method with a strip width of 6 meters (Control treatment), the creek created on both sides of the tree row (Ditcher), reducing the strip width through the border created in the middle of the row of trees (Border) and the bed of Sine-Morghi created on both sides of the rows of trees (Kadval). The amount of irrigation water according to the inflow to each treatment and the time of cut off based on the management applied by the gardener in Control, Border, Kadval and Ditcher treatments was 8400, 4648, 4200 and 3080 cubic meters per hectare, respectively. The results showed that in both years of experiment in all treatments, irrigation water productivity increased compared to the control treatment. So that in the first year that the trees had good yield, the rate of increase in Ditcher, Kadval and Border treatments compared to the control treatment was 120%, 91% and 62%, respectively. Also, according to the results of calculating the nutritional indices of pistachio leaf nutrients, it was observed that Ditcher treatment had the highest nutritional balance in the first year (1.6) and second (26.5) compared to the control. In terms of farm efficiency, there was no significant difference between the three types of Ditcher, Border, and Kadval machines, so there is no difference between their selection in the preparation of a water distribution bed for pistachio trees. Finally, Ditcher treatment was proposed as the best irrigation treatment for pistachio trees in the tested orchard. [ABSTRACT FROM AUTHOR]

Optimum water need of sweet pepper and the critical irrigation level to be applied in order to achieve a reasonable economic yield was determined. Greenhouse (controlled) was conducted with sweet pepper subjected to three (3) varying water applications; 100% full irrigation treatment (FIT), 70% FIT and 50% FIT. Crop water use (evapotranspiration) was determined using the water balance method. For the agronomic parameters measurement, weekly measurements of plant height, stem diameter, number of leaves and canopy temperature were measured. The sweet pepper were determined in batches during harvest. Result showed that the growth parameters significantly (p < 0.05) increased with increase in water application. The highest value of 707.78 g was recorded at irrigation treatment that received 70% of FIT while the least value was recorded in treatment that received the least amount with a value of 665.2 at 50% FIT. Overall, similar yield (p > 0.05) was observed in the yield quantification. This showed that about 50% of irrigation can be saved to irrigate additional plant. Highest values of irrigation for the irrigation and crop water efficiencies were obtained at the deficit irrigation. [ABSTRACT FROM AUTHOR]

To reduce the harmful environmental effects of fertilizer application in irrigated agriculture, evaluating alternative fertigation management practices is essential in different irrigation systems. This study aims to evaluate the water movement and nutrient transport in the corn root zone under subsurface drip irrigation (SDI) using the HYDRUS-2D model in different irrigation and fertigation management practices. For this purpose, a 2-year field experiment was conducted in the growing seasons of 2018 and 2019. Three different irrigation levels, three fertilizer application frequencies, and two fertilizer injection times during each irrigation event were selected as different treatments. Irrigation levels included full irrigation (FI) and two deficit irrigations (DI) at 75% and 50% of the plant's net requirement (DI75 and DI50). Three different fertigation frequencies including weekly, once every 2 weeks, and local recommendations in three splits were considered, and the fertilizer was injected at the end and middle of each fertigation event. HYDRUS (2D) was calibrated based on the conducted field experiments and the calibrated model was then utilized to simulate nitrate leaching and N uptake by corn in different treatments. The results indicated that the highest nitrate root uptake occurred in fertilizer application with three splits in all irrigation levels. N uptake in weekly and once every 2 weeks treatment in full irrigation was about 46% of the total applied fertilizer. However, reducing fertigation frequency to three splits increased N uptake to 59% in the studied fine-textured soil. As a result, it reduced the amount of residual nitrate in the soil at the end of the growing season which has high leaching potential. The findings of this study are significant in reducing the environmental effects of chemical fertilizer abuse and increasing the efficiency of fertilizer uptake by corn in SDI. [ABSTRACT FROM AUTHOR]

Weather forecasts can enhance the utilization of scientific irrigation scheduling tools, crucial for maximizing agricultural water use efficiency. This study employed quantitative weather forecasts of 3-, 7- and 14-day lead times from a weather application programming interface (API) to generate irrigation schedules using the AquaCrop-OSPy model for maize, cotton and sorghum under different regulated deficit irrigation scenarios. The study aimed to determine the suitability of forecast lengths for irrigation scheduling under varying pumping capacities of center pivots (114 m3h−1, 182 m3 h−1 and 250 m3 h−1) in the Texas High Plains and Rio Grande Basin regions, United States. A comparative analysis was carried out to evaluate the irrigation schedules and corresponding crop yields simulated using forecasted and observed weather data. Results indicated that using shorter forecast time allowed the crop model to capture more precise variations in weather patterns, however, shorter lead times also caused over-irrigation in some scenarios. Use of longer lead times tended to be less suitable for scheduling irrigation during water-sensitive growth stages. Center pivots with large pumping capacities and application rates benefited more from longer forecast lengths due to their ability to adapt to weather fluctuations. Unplanned irrigation application occurred in some instances, primarily attributed to uncertainties in weather forecasts and limitations of the crop model. The approach developed and evaluated in this study supports water conservation efforts by promoting scientific irrigation scheduling in weather-data-poor and low adoption regions. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O) exacerbates the greenhouse effect and thus global warming. Agricultural management practices, especially the use of nitrogen (N) fertilizers and irrigation, increase soil N2O emissions. As a vital sector of global agriculture, specialty crop systems usually require intensive input and management. However, soil N2O emissions from global specialty crop systems have not been comprehensively evaluated. Here, we synthesized 1137 observations from 114 published studies, conducted a meta‐analysis to evaluate the effects of agricultural management and environmental factors on soil N2O emissions, and estimated global soil N2O emissions from specialty crop systems. The estimated global N2O emission from specialty crop soils was 1.5 Tg N2O‐N year−1, ranging from 0.5 to 4.5 Tg N2O‐N year−1. Globally, soil N2O emissions exponentially increased with N fertilizer rates. The effect size of N fertilizer on soil N2O emissions generally increased with mean annual temperature, mean annual precipitation, and soil organic carbon concentration but decreased with soil pH. Global climate change will further intensify the effect of N fertilizer on soil N2O emissions. Drip irrigation, fertigation, and reduced tillage can be used as essential strategies to reduce soil N2O emissions and increase crop yields. Deficit irrigation and non‐legume cover crop can reduce soil N2O emissions but may also lower crop yields. Biochar may have a relatively limited effect on reducing soil N2O emissions but be effective in increasing crop yields. Our study points toward effective management strategies that have substantial potential for reducing N2O emissions from global agricultural soils. [ABSTRACT FROM AUTHOR]

The total land used for land-based food farms is less than 1% in Singapore. As a result, more than 90% of Singapore's food needs are imported. To strengthen food security, Singapore has set a target to develop the capability and capacity of the agri-food industry to locally produce 30% of its nutritional needs by 2030. To achieve this goal, technology is the key to helping farms to "grow more with less". This review first discusses how aeroponic systems have been adapted for growing all kinds of leafy vegetables in the tropics through the manipulation of root-zone temperature and heat priming to save power energy. Growing vegetable crops indoors and in greenhouses not only allows the growers to achieve high productivity but also enables them to enhance nutritional values. The second part of this paper emphasizes how to achieve substantial yield through deficit irrigation with higher nutritional quality in a cost-effective manner. Growing crops vertically has become increasingly popular, as it increases land use. We establish a commercially viable LED-integrated aeroponic system to grow vegetables vertically. The last part of the paper discusses the impacts of LED spectral quality, quantity, and duration on vegetable production. [ABSTRACT FROM AUTHOR]

Sustainable fruit orchard development in arid areas is severely affected by the scarcity of fresh water. To mitigate the lack of fresh water, the use of low-quality water for irrigation is becoming a common practice in several margin areas. However, salinity is considered one of the most important environmental constraints limiting the successful crop production. Therefore, the effects of deficit irrigation strategies using saline water (3.1 dS m−1) on soil water content, soil salinity, and yield of commercial peach orchard were investigated. Three irrigation treatments were considered: a Control, full irrigated (FI); and partial root-zone drying (PRD50); and deficit irrigation (DI) strategies irrigated at 50% ETc. These levels of water supply allowed for contrasting watering conditions with clear distinction between irrigation treatments. The differential pattern in soil moisture was accompanied by that of soil salinity with an increase in all FI treatments (16–25%). The results indicated that soil salinity increased with increasing water supply and evaporative demand during the growing season from January (3.2 dS m−1) to August (6.6 dS m−1). Deficit irrigation strategies (DI, PRD50) induced more soil salinity along the row emitter compared to the Control due to insufficient leaching fractions. By the end of the growing season, the soil salinity under long-term saline drip irrigation remained stable (5.3–5.7 dS m−1). An efficient leaching action seemed to be guaranteed by rainfall and facilitated by sandy soil texture, as well as the high evaporative demand and the important salt quantity supplied, which maintain the deficit irrigation strategies as valuable tools for water saving and improving water productivity. The significant water saving of 50% of water requirements induced a fruit yield loss of 20%. For this reason, DI and PRD50 could be reasonable irrigation management tools for saving water and controlling soil salinity in arid areas and on deep sandy soil. [ABSTRACT FROM AUTHOR]

In order to investigate the effect of different levels of zeolite and defficit irrigation on some physiological traits, oil and protein yield of lineeed crop, in a split plot experiment were conducted in based on a randomized complete blocks design with three replications in Shahrekord University in 2016. Defficit irrigation as the main factor in four levels, including 50 (control), 80, 130 and 180 mm of evaporation from the class A evaporation pan, and the use of zeolite as a secondary factor in three levels, including non-use (control) and the use of 5 and 10 tons/hectares were considered. The results of the experiment showed that the application of zeolite at a probability level of 1% had a significant effect on the content of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids of leaves, oil yield, nitrogen percentage, protein percentage and seed protein yield, allthogh, the oil percentage was not affected by this treatment. Also, different levels of irrigation were significant on all the mentioned traits at the level of 1%. The interaction of the simple effect of the treatments on protein percentage, nitrogen percentage, chlorophyll a and total chlorophyll was significant at the 1% probability level and on oil yield and chlorophyll b at the 5% probability level, and showed non-significance on the oil percentage, protein yield and carotenoid . The highest amount of the above traits was obtained from the control treatment (normal irrigation) and the application of 10 tons zeolite /hectare, and the lowest amount of the traits was obtained from the treatment of 180 mm of evaporation from the evaporation pan and no application of zeolite. The results showed that the application of zeolite has significantly improved the performance of the lineeed crop in non-stress conditions to moderate drought stress conditions. Introduction Oilseeds are big sources of energy and protein. Linseed (Linum usitatissimum) is an oilseed crop with a history of several thousand years of cultivation, which seeds contain 30 to 50% edible oil. Linseed is a one-year herbaceous plant belonging to the Linaceae family, which is believed to have originated in the western Mediterranean (Omidbeighi, 2014). The protein content of linseed seeds is between 29-44%. It has been reported (Iran-Nejad, 2014). Water defficit is one of the significant and important stresses affecting the growth, development and functions crops. Water stress in plants may lead to physiological disorders such as reduction of photosynthetic pigments, reduction of assimilates. and reduce growth (Petropoulos et al., 2008). water stress reduces the absorption of nutrients through the roots due to the reduction of soil water and the reduction of the distribution of nutrients in the soil tissue; it also reduces the transfer of nutrients from the roots to When plants are under stress, their chlorophyll content decreases and as a result, photosynthetic activity also decreases in plants under stress. Materials and Methods The field experiment has been conducted as a split plot based on a randomized complete block design with three replications at the research farm of Shahrekord University on linseed crop in 2016. The main factor water stress included four levels of 50 (control), 80, 130, the lowest irrigation level and 180 mm of evaporation from the evaporation pan, and the secondary factor of zeolite consumption in three levels, including control (without zeolite), 5 and 10 tons of zeolite per hectare. The traits of chlorophyll concentration (a, b and total), yield and yield components, thousand seed weight, oil percentage, seed oil yield, seed nitrogen percentage, protein percentage and seed protein yield were measured. Results and Discussion The experiment results showed that the application of zeolite on chlorophyll a, chlorophyll b, total chlorophyll and carotenoid, oil yield, nitrogen percentage, protein percentage and seed protein yield was significant at the probability level of 1% and it was not significant on oil percentage. Also, different irrigation levels were significant on all the mentioned traits at the level of 1%. The interaction effect of treatments on protein percentage, nitrogen percentage, chlorophyll a and total chlorophyll was significant at one percent probability level, and on oil yield and chlorophyll b at five percent probability level. It was not significant on oil percentage, protein yield, and carotenoid. The results showed that deficit irrigation reduced all investigated traits. So that the maximum amount of the above traits were obtained from the control treatment (normal irrigation) and the application of 10 tons of zeolite per hectare, and the lowest amount of traits was obtained from of 180 mm evaporation from the evaporation pan and the absence of zeolite application. The results showed that the use of zeolite, has significantly increased the yield of linseed crop under non-stress conditions to moderate drought stress conditions, but under severe stress conditions, the limiting effects of drought stress have significantly reduced the studied traits. Conclusion The results showed that the use of zeolite, due to its property of absorbing water, maintaining and increasing the availability of moisture, reduces the intensity of drought stress and moderates the destructive effects of drought stress on the content of chlorophyll, carotenoid, and protein in plants. In this research, it was found that the use of 10 tons of zeolite per hectare had a favorable effect on reducing the damage caused by drought stress in linseed crops, and considering the abundance of zeolite in different parts of the country and its reasonable economic price, as well as, the problem of drought stress in Iran, the use of Zeolite can improve plant access to soil water and increase yield and quality of oil and protein of linseed under water deficit conditions. [ABSTRACT FROM AUTHOR]

The basic partitioning of precipitation P into evapotranspiration ET and run‐off Q is known as the "central problem of hydrology." ET depends primarily on precipitation, P, and potential evapotranspiration, PET, which are connected by the biological process of photosynthesis. Photosynthesis is the fundamental step underlying the productivity of plant ecosystems. An important measure of plant productivity is the creation of plant biomass, which is quantified by net primary productivity, NPP. NPP is most parsimoniously related simply to the evapotranspiration, ET. The dependence of NPP (ET) appears to be in the form of a power law with an upper limit derived from the maximum plant‐available solar energy accessible on Earth. However, theoretical, rather than phenomenological, treatments relating ET and its complementary variable, run‐off (P − ET ≡ Q) to climate variables that measure the available energy (PET) and available water (P) (known as the water balance) are, at best, scarce, and their continued application to predicting NPP (P, PET) even more so. One theory developed recently to predict the water balance is based on determining how to divide P into Q and ET in such a way as to maximize NPP. Substitution of the resulting optimized ET (P, PET) into the function NPP (ET) then yields NPP (P, PET). We investigate the possibility that this new theoretical framework, which yields ET(P, PET) based on ecological optimality and percolation theory, can predict the dependence of NPP (P, PET). If the prediction of NPP (P, PET) is verified, this result may lead to significant progress in other areas, including the problem of the chief causes of geographical variability of species richness. Key Points: A novel approach linking evapotranspiration ET to climate variables is now applied to net primary productivity NPPET was obtained from the maximum NPP for given climatic conditions, consistent with maximum diversityResulting predictions of NPP as functions of precipitation P and potential evapotranspiration PET agree with observation [ABSTRACT FROM AUTHOR]

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To investigate the effects of drought stress and different LED lights on yield, water productivity and some morphologic characteristics of wheat plant in early stages of growth, a factorial experiment was performed in the form of a completely randomized design in 2022 in the research greenhouse Torbat-e Jam University. The effects of drought stress included three levels (100, 75 and 50 percent of water requirements) and the effect of different LED lights including six levels (white, 70% red + 30% blue, 100% red, 70% blue + 30% red, 100% blue and 50% red + 50% blue) on wheat plant in the early stages of growth were investigated. The results of this research showed that by applying drought stress to the amount of 75 and 50% of the water requirement of the plant, fresh weight of aerial parts, dry weight of aerial parts, root fresh weight, root dry weight, plant length, chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, potassium concentration, Phosphorus concentration and magnesium concentration decreased and water productivity increased by 18/52% and 27/94% respectively. Also, the results showed that among the different types of LED light application, the highest amount in fresh and dry weight of aerial parts, fresh and dry weight of roots, plant length and water productivity in 70% red + 30% blue light and the highest amount of pigments photosynthetic parameters were obtained in wheat plant in 50% red + 50% blue light. the results showed that the highest concentration of potassium occurred in 100% red light, phosphorus concentration in white light and magnesium concentration in 50% red + 50% blue light. Results demonstrated that the combination of 70% red light with 30% blue light increased water productivity and morphologic characteristics of wheat plant. [ABSTRACT FROM AUTHOR]

We have presented a new scheme, "optimized irrigation", in which irrigation depth is determined such that net income during each interval is maximized considering weather forecasts and the price of water using WASH_2D, numerical simulation mod- els of water flow and solute transport in soils and crop growth. To evaluate whether the optimized irrigation is also able to restrict salinity stress without any intentional leaching, we carried out an irrigation experiment in a sandy field. Potato was grown in a green- house in Tottori, Japan, using a drip irrigation system whose emitter distance was 20 cm and lateral spacing was 60 cm. Seeds were sown on 3 September below each emitter. Three treatments were established: 1) irrigation with fresh water (F), 2) irrigation with 2 g/L of NaCl solution (C), 3) irrigation with 2 g/L of NaCl solution and irrigation depth was determined with the proposed scheme (O). "F" and "C" were irrigated with automated irrigation systems using soil moisture sensors. Leachings were carried on "C" out on 12 (10 mm) and 21 (16 mm) November. "F" received the lowest amount of water owing to zero leaching requirement while "O" and "C" re- ceived almost the same mount. Net income was calculated under a producer price of 0.5 $/kgFW of tuber and the price of saline water at 0.5 $/m². Treatment O gained the as high net income as F, revealing the effectiveness of the proposed scheme. [ABSTRACT FROM AUTHOR]

Field experiments were conducted in the cropping years 2012 and 2013 with four irrigation treatments, I1, I2, I3, and I4, respectively, corresponding to full irrigation, 20, 35, and 50% less than the crop water requirement in a semi-arid region of Iran. Data were used for calibration (2012) and validation (2013) of biomass (B), grain yield (GY), soil water content (SWC), canopy cover (CC), and evapotranspiration (ET) of canola by the AquaCrop model. Model coefficients were calibrated for I1 treatment in 2012, and the calibrated parameters were used for other treatments in both years. Based on the results, the NRMSE value for SWC ranged from 10 to 20%. Simulated and measured SWC for the four water treatments showed that AquaCrop has good accuracy. Overall, the results of the model in simulating SWC for both years were satisfactory. AquaCrop provided overestimation in the calibration phase of ET and underestimation in the ET validation phase. The results also showed that AquaCrop is overestimated in the simulation and prediction of CC and is less satisfactory under water stress. The model evaluation showed that AquaCrop can simulate B and GY with high accuracy. In general, AquaCrop was identified as a good tool for studying irrigation management, crop B and GY, CC, SWC, and other factors affecting the canola growth in the studied fields and climate. [ABSTRACT FROM AUTHOR]

Water scarcity constrains the sustainable development of Chinese agriculture, and deficit irrigation as a new irrigation technology can effectively alleviate the problems of water scarcity and water use inefficiency in agriculture. In this study, the drip irrigation cotton field under film in Xinjiang was taken as the research object. Meta-analysis and machine learning were used to quantitatively analyze the effects of different farm management practices, climate, and soil conditions on cotton yield and water use efficiency under deficit irrigation, to investigate the importance of the effects of different factors on cotton yield and water use efficiency, and to formulate appropriate optimization strategies. The results showed that deficit irrigation significantly increased cotton water use efficiency (7.39%) but decreased cotton yield (−15.00%) compared with full irrigation. All three deficit irrigation levels (80~100% FI, 60~80% FI, and 40~60% FI; FI: full irrigation) showed a significant decrease in cotton yield and a significant increase in water use efficiency. Under deficit irrigation, cotton yield reduction was the smallest and cotton water use efficiency increased the most when planted with one film, two tubes, a six-row cropping pattern, an irrigation frequency ≥10 times, a nitrogen application of 300~400 kg·ha−1, and a crop density ≥240,000 per hectare, and planted with the Xinluzhong series of cotton varieties; deficit irrigation in areas with average annual temperature >10 °C, annual evapotranspiration >2000 mm, annual precipitation <60 mm, and with loam, sandy soil had the least inhibition of cotton yield and the greatest increase in cotton water use efficiency. The results of the random forest showed that the irrigation amount and nitrogen application had the greatest influence on cotton yield and water use efficiency. Rational irrigation based on optimal management practices under conditions of irrigation not less than 90% FI is expected to achieve a win–win situation for both cotton yield and water use efficiency. The above results can provide the best strategy for deficit irrigation and efficient water use in drip irrigation cotton under film in arid areas. [ABSTRACT FROM AUTHOR]

Planting vegetation on slopes is an effective way of improving slope stability while enhancing the aesthetic appearance of the landscape. However, plants growing on slopes are susceptible to natural drought stress (DS) conditions which commonly lead to water deficit in plant tissues that affect plant health and growth. This study investigated the photosynthetic gas exchange, plant water status and proline accumulation of three tropical perennials namely Clerodendrum paniculatum, Ipomoea pes-caprae and Melastoma malabathricum after being subjected to DS and re-watering (RW). During DS, there was a significant decrease in light-saturated photosynthetic CO2 assimilation rate (Asat), stomatal conductance (gs sat), and transpiration rate (Tr) for all three plant species. Leaf relative water content, shoot water potential, and leaf, stem and root water content also declined during DS. Proline concentration increased for all three species during DS, reaching especially high levels for C. paniculatum, suggesting that it heavily relies on the accumulation of proline to cope with DS. Most of the parameters recovered almost completely to levels similar to well-watered plants after RW, apart from M. malabathricum. Strong linear correlations were found between Asat and gs sat and between gs sat and Tr. Ultimately, C. paniculatum and I. pes-caprae had better drought tolerance than M. malabathricum. [ABSTRACT FROM AUTHOR]

Background: Water-scarce locations necessitate the deployment of creative and sustainable techniques for managing water for agricultural production. Field experiment was conducted at the Experimental Research Farm of National Research Centre, Nubaria region, Egypt to alleviate the harmful effect of water stress on the yield of Mediterranean barley varieties (Giza 125, Tombari, Ksar Megrine and Tamellat) by compost (0.0, 2.0, 4.0, 6.0-ton fed−1) and arginine application (0.00 and 1000 ppm) under deficit irrigation. The amounts of irrigation water applied were "900 and 450" m3 fed−1 to sufficient irrigation and deficit irrigation, respectively. Results: The greatest and most significant values of the chlorophyll values and relative water content values obtained at the treatment supplied with 6.0-ton compost fed−1 and sprayed with Arginine. There was a significant dramatic decrease in proline content with increasing compost application rates and treated barley plants by Arginine for all the studied barley varieties under both studied irrigation treatments. Increasing compost application rate is associated with significant increase in number of spike m−2 without or with arginine. Barley Tombari variety received 6.0-ton compost fed−1 gained changes to give a greatest significant value of grain (ton fed−1) under sufficient irrigation and Tamellat under deficit irrigation situation. The significant maximum values of the grain yield (1.96- and 2.09-ton fed−1) were attained at Tombari and Tamellat varieties which received 6.0-ton fed−1 compost with or without arginine under sufficient irrigation. The increases in compost rate increment changes to incremented grain yield values with arginine application more than untreated one. The greatest and significant grain yield was found at the treatment received 6.0-ton compost fed−1 with arginine foliar application. Conclusion: Compost application has an important role in maintaining greatest water use efficiency for plant and arginine application reported to contribute in reduction in destructive effects of a biotic stress thus their importance in increasing the barley production under water stress. [ABSTRACT FROM AUTHOR]

This article presents a dataset that can be used to estimate alfalfa leaf area and predict leaf area index (LAI). The dataset includes meteorological data, soil moisture measurements, and various parameters associated with alfalfa growth. It fills a gap in publicly available alfalfa growth data in northwest China and provides essential data for optimizing water and nitrogen strategies in alfalfa field management. The document also provides information on the measurement and analysis of LAI in alfalfa plants under different water and nitrogen treatments. The research articles compiled in the document cover a range of topics related to alfalfa growth, yield, and quality, providing valuable insights for researchers and practitioners interested in improving alfalfa cultivation. [Extracted from the article]

The shortage of water resources is a key factor restricting the sustainable development of agriculture, and the optimal allocation of agricultural irrigation water resources is of great significance to guarantee food and water security. Based on the main types of optimal allocation models of agricultural irrigation water resources, the research progress on single crop irrigation optimal decision-making, multi-crop water and soil resources optimal allocation, and canal system water resources optimal operation were systematically reviewed. In the traditional single crop irrigation optimal decision-making, the maximum crop yield or economic benefit was usually selected as the optimization objective. With the improvement of people’s living standard, consumers pay more attention to crop quality. And the optimal decision-making of water-saving irrigation theory based on the response of water and quality for improving quality of crop has gradually become a research focus. The multi-crop water and soil resources optimal allocation mainly includes the adjustment of crop planting structure and allocation of irrigation water resources in the irrigation district, which has undergone a transformation from single objective to multiple objectives, structural optimization to spatial layout optimization, and only focusing on the improvement of crop yield to the water-energyfood-ecology collaborative optimization. According to the different optimization objectives, the canal system water resources optimal operation is usually divided into two categories. Firstly, the objective is to optimize the benefit indicators of irrigation district, such as crop yield, economic benefits, water fee income of the irrigation management department, and the utilization efficiency of water and soil resources. Secondly, the objective is to optimize the operation and management indexes of hydraulic engineering in irrigation districts, such as the least water loss during the canal operation, water delivery time, differences in the continuous water diversion time of each rotating irrigation group, water shortage, and smooth water flow transition. In addition, the main problems and future research plans in the optimal allocation model of agricultural irrigation water resources were pointed out. The study suggested that the optimal allocation model of irrigation water resources should be improved in the following four aspects: 1) Building more physiological crop water-quality models; 2) Achieving optimal allocation of irrigation water resources under the scenarios of climate change and human activities; 3) Building systematic optimal allocation model of irrigation water resources that fully consider canal systems, irrigation districts, crops, and growth stages; 4) Establishing irrigation optimization decision-making models with the objective of minimum soil evaporation; Overall, this review provides valuable information for domestic researchers. [ABSTRACT FROM AUTHOR]

Tomato (Solanum lycopersicum L.) is an important vegetable crop that grows easily under controlled conditions, such as in greenhouses and hydroponics. To overcome freshwater scarcity, researchers are searching for alternatives to groundwater sources such as desalinated water (saline water) for irrigation. High salinity in irrigation water alters physiological functions and crop development, thereby reducing the yield. Best management practices and the use of grafted tomato plants on salt-tolerant rootstocks can alleviate salinity stress. The present study was conducted to address the impact of salinity stress on leaf transpiration (Tr), stomatal conductance (gs), photosynthesis (Pn), leaf chlorophyll content, proline content, and yield of hydroponically cultivated tomato plants. Saline (NaCl) water was used for the preparation of nutrient solution with three salinity levels, electrical conductivity (EC, dS m−1) of 2.5 (control), 6.0, and 9.5. Three commercial tomato cultivars (Valouro-RZ, Ghandora-F1, and Feisty-Red) were used. Both self-rooted plants and plants grafted onto Maxifort rootstocks were transplanted onto a perlite substrate. The recorded data revealed that all studied cultivars were critically affected by higher salinity (≈ 9.5 dS m-1) compared to low (≈ 2.5 dS m-1) and medium (≈ 6.0 dS m-1) salinity levels. The Variations in Tr, Pn, gs, chlorophyll content of leaf, and yield between medium and high salinity trials were reported at 3%, 5%, 9%, 5%, and 7.1%, respectively, whereas no significant differences were observed between low and medium salinities. However, at medium salinity levels, grafted plants performed better in photosynthesis than non-grafted plants. This is due to the accumulation of leaf proline, which maintains osmotic regulation and photosynthetic activity by preventing cell damage at medium salinities. Hence, this study confirmed the use of saline water for growing tomatoes under hydroponic conditions up to an EC of 6.0 dS m-1 including the EC of nutrient fertilizers. [ABSTRACT FROM AUTHOR]

In arid and semi-arid regions, irrigation is crucial to mitigate water stress and yield loss. However, the overexploitation of water resources by the agricultural sector together with the climate change effects can lead to water scarcity. Effective regional water management depends on estimating irrigation demand using maps of irrigable areas or national and regional statistics of irrigated areas. These statistical data are not always of reliable quality because they generally do not reflect the updated spatial distribution of irrigated and rainfed fields. In this context, remote sensing provides reliable methods for gathering useful agricultural information from derived records. The combined use of optical and radar Earth Observation data enhances the probability of detecting irrigation events, which can improve the accuracy of irrigation mapping. Hence, we aimed to utilize Sentinel-1 (VV and VH) and Sentinel-2 (NDVI) data to classify irrigated fruit trees and rainfed ones in a study area located in the Castilla La-Mancha region in Spain. To obtain these time-series data from Sentinel-1 and Sentinel-2, which constitute the input data for the classification algorithms, a tool has been developed for automating the download from the Sentinel Hub. This tool downloads products organized by tiles for the region of interest and for the entire required time-series, ensuring the spatial repeatability of each pixel across all products and dates. The classification of irrigated plots was carried out by SVM Support Vector Machine. The employed methodology displayed promising results, with an overall accuracy of 88.4%, indicating the methodology's ability to detect irrigation over orchards that were declared as non-irrigated. These results were evaluated by applying the change detection method of the σ p 0 backscattering coefficient at plot scale. [ABSTRACT FROM AUTHOR]