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Determining the optimal phosphorus rates and deficit irrigation levels is key to enhancing soybean productivity in the Jawi District, Northwest Ethiopia. Soybean is a vital cash crop in Jawi District, Northwest Ethiopia, and improving its productivity is crucial for food security and community socioeconomic status. The optimal phosphorus and deficit irrigation rates in this region remain unresolved. The aim of this study was to optimize soybean productivity in this region by determining the optimal phosphorus rates and deficit irrigation levels. The experiment was conducted during irrigation seasons 2021/22 and 2022/23 using a split-plot design with an RCBD arrangement. The results showed that combining P rates of 10, 20, 30, and 40 kg ha-1 with 100% ETc. significantly increased soybean grain production. Similarly, soybean grain yield increased at P rates of 0, 10, 20, 30, and 40 kg ha-1 P with 75% ETc. The highest water productivity recorded was 0.29 kg m-3 at 50% ETc. This study suggests that combining P rates of 10, 20, 30, and 40 kg ha-1 P with 100% ETc. and P rates of 0, 10, 20, 30, and 40 kg ha-1 P with 75% ETc. could significantly enhance soybean productivity. Implementing these strategies could lead to more sustainable and efficient agricultural practices in Jawi District, thereby improving crop yields and overall profitability. [ABSTRACT FROM AUTHOR]

Climate change-caused water deficiency is a major threat to crop production. Different strategies such as biochar and mycorrhiza are suggested as a solution to improve water storage in the soil and increase plant tolerance to moisture deficiency. This study tested the hypothesis that under deficit irrigation conditions, the combined application of biochar and mycorrhiza can increase maize photosynthesis activity, growth, and water use efficiency (WUE). A greenhouse experiment was established to understand the effect of biochar and mycorrhizal inoculation with deficit irrigation on maize (Zea mays L.) growth, photosynthesis activity, and WUE. A factorial randomized pot experiment was designed using three biochars (B) doses from three different feedstock (DF) and three mycorrhizae (M) species (without mycorrhizae, Rhizophagus clarus and indigenous mycorrhiza), with three different irrigation (I) levels, namely, I100, I75, and I50 respectively 100%, 75%, and 50% of field capacity. For each biochar application, of 0%, 1%, and 2% rates of soil weight were applied. Maize plant dry matter (DM), photosynthesis activities, and leaf water use efficiency (WUEL) were measured. The results showed that deficit irrigation levels, such as I75 and I50 can be used for maize plant growth. Mycorrhizal inoculation increased maize plant growth between 8.2% and 8.9%, whereas biochar increased growth. In addition, mycorrhizal inoculation increased the photosynthesis activity by 9.3%. All the biochars increased maize growth and photosynthesis activity compared to the control, however, poultry manure biochar had the highest growth, photosynthesis activity, and WUE. In addition, statistically, there were no significant differences between B0*M0*I100 and B*M*I50 applications in terms of photosynthesis activity, WUE, and DM. Combined application of biochar and mycorrhiza statistically reduced irrigation water use by 50% without affecting plant DM production. [ABSTRACT FROM AUTHOR]

The objective this study was to evaluate the effects of foliar application of ascorbic acid – AsA on the production and postharvest quality of sour passion fruit under deficit irrigation strategies. The experimental design was randomised blocks, in a split-plot scheme, with plots consisting of six strategies of irrigation with water deficit, based on crop evapotranspiration – ETc (irrigation with 100% ETc during the entire cycle – S1; irrigation with 50% ETc in the different stages: vegetative – S2; flowering – S3; fruiting – S4; and successively in the vegetative/flowering stages – S5; and vegetative/fruiting stages – S6) and three concentrations of AsA (0, 88.06 and 176.12 mg/L), with three replicates and three plants per plot. Water deficit reduces the production of sour passion fruit, regardless of the phenological stage of the plants without AsA application. Irrigation with water deficit in the flowering stage (50% of crop evapotranspiration) reduces the physical and chemical quality of sour passion fruits. Ascorbic acid in applied levels was effective in alleviating the effects of water deficit on production, with emphasis on the concentration of 176.12 mg/L on the quality of sour passion fruits, in the period from 160 to 220 days after transplanting. [ABSTRACT FROM AUTHOR]

AbstractWater deficit is the most common abiotic stress and at least 75% of corn fields in Iran are exposed to drought stress during different stages of growth. humic acid (HA) and nanosilver (NS) can help mitigate abiotic stresses in plants; especially drought stress. A field experiment was conducted to study the effect of humic acid and nanosilver on the physiological traits and yield of corn during two crop years. Experimental treatments were including deficit irrigation (100%, 80%, 60% of crop water requirement (CWR)) and nanosilver (0 (NS0), 60 (NS60), 80 (NS80) and 100 (NS100) microliters/liter/ha) and humic acid (control (HA0), 500 (HA500) and 1000 (HA1000) g/ha). The highest amount of chlorophyll a, b and total in 100% CWR+NS60+HA1000 was obtained. The highest amount of proline in 60% CWR + NS60 +HA1000 as well as treatment NS0 +HA1000 were observed. In all irrigation levels, the application of NS100 has reduced chlorophyll a and total. The yield components were affected by HA and nanosilver foliar spraying. The highest grain yield was observed in 100% CWR with the application of NS60 +HA500 at the rate of 10,582 kg/ha. In conditions of 100% CWR, nanosilver concentrations had a positive effect on plant growth and yield, and with increasing stress, high concentrations of nanosilver had a negative effect on growth and yield, but with the combined application of nanosilver and HA, the effect of drought stress decreased, which indicates the positive effect of HA in improving plant growth and yield. [ABSTRACT FROM AUTHOR]

This work was conducted over three-year monitoring seasons of three almond cultivars (Guara, Marta, and Lauranne) subjected to deficit irrigation in combination with cover crops in a Mediterranean semiarid area (SW, Spain). Four water–soil treatments were evaluated based on the conjunction of two irrigation strategies: fully irrigated (FI), covering 100% of the ETC, and regulated deficit irrigation (RDI), with two soil-management systems: bare soil (BS) and cover crop based on a mixture of vetch (Vicia sativa L.) and oat (Avena sativa L.) (CC). Throughout the study period in trees, the yield, the stem water potential (Ψstem), leaf nutrient content (N, P, K, Ca, Mg, Na, Fe, Zn, Mn, and Cu) in soils, organic carbon, microbial biomass, fluoresceine diacetate, and enzymatic activities (dehydrogenase, protease, β-glucosidase, and alkaline phosphatase) were determined. In addition, the dry matter and carbon fixation by plant covers were evaluated. For Guara and Lauranne, yield reductions (22 and 26%, respectively) were found for water-stressed (RDI-CC) plots with respect to non-stressed combination (FI-CC) plots, contrasting with cv. Marta, without a significant impact on productivity in all combinations. That is, the RDI (~3.000 m3 ha−1) strategy enabled acceptable productivity, offering promising possibilities for cultivation performance under water-scarcity scenarios. Important differences in Ψstem could be observed and ascribed to irrigation strategies, especially for Guara and Lauranne, but without significant effects due to the soil-management systems applied. No differences were observed in the tree nutritional status due to the presence or absence of CC; however, its presence increased the fixation of atmospheric carbon, which was not the case under BS conditions. Additionally, CC significantly fostered the microbial processes and enzymatic activities, particularly in upper soil layers (0–10 cm) and with plenty of water supply in FI-CC plots and to a lesser extent in RDI-CC plots, which could encourage prominent aspects for soil quality and health restoration. Thus, the cover crop is congruent with RDI to facilitate soil functionality and water savings in a changing climate, contributing to resilient farming systems in the Mediterranean environment. [ABSTRACT FROM AUTHOR]

Context: Preharvest granulation of Imperial mandarins is a significant problem for the Australian market. Causes of, and solutions for, this physiological disorder are poorly understood despite decades of research worldwide. Aims: This research aimed to find management practices for growers to reduce granulation. Methods: A 5-year on-farm trial in central Queensland, Australia, compared standard versus deficit irrigation and five rates of winter nitrogen application. Key results: Reducing water (irrigation plus rainfall) in the 16–18 weeks following flowering reduced granulation in 3 of 5 years. Granulation increases with ratio of total water received to evapotranspiration, particularly in low crop load years. Higher nitrogen applications reduced granulation in 4 of 5 years, although treatment means were only significantly different at α = 0.05 in 1 year. Granulation increased with stronger early spring flush growth in a low crop load year and with later spring flush growth in one of two high crop load years. The deficit irrigation treatment had less spring flush growth and higher fruit set than the control in all years. Higher nitrogen treatments had more flush growth in high crop load years and less in low crop load years. Our data suggests competition between flush growth and fruit development for mineral resources and/or carbohydrates is a factor in the variability of granulation from fruit to fruit, but crop load is more important. Conclusions: The three key strategies to minimise granulation are to maintain high crop loads, reduce irrigation after flowering, and apply sufficient nitrogen in winter. Implications: This research will improve fruit quality for the consumer and financial returns to growers. Granulation, a physiological disorder in which citrus fruit are white, dry and tasteless, is a significant problem for Imperial mandarins in Australia. We discovered that excessive irrigation and insufficient nitrogen fertilisation are important causes of granulation and three key strategies to minimise granulation are to maintain high crop loads, reduce irrigation after flowering, and apply sufficient nitrogen in winter. This research will improve fruit quality for the consumer and financial returns to growers. [ABSTRACT FROM AUTHOR]

Remote sensing is now a valued solution for more accurately budgeting water supply by identifying spectral and spatial information. A study was put in place in a Vitis vinifera L. cv. Cabernet-Sauvignon vineyard in the San Joaquin Valley, CA, USA, where a variable rate automated irrigation system was installed to irrigate vines with twelve different water regimes in four randomized replicates, totaling 48 experimental zones. The purpose of this experimental design was to create variability in grapevine water status, in order to produce a robust dataset for modeling purposes. Throughout the growing season, spectral data within these zones was gathered using a Near InfraRed (NIR) - Short Wavelength Infrared (SWIR) hyperspectral camera (900 to 1700 nm) mounted on an Unmanned Aircraft Vehicle (UAV). Given the high water-absorption in this spectral domain, this sensor was deployed to assess grapevine stem water potential, Ψstem, a standard reference for water status assessment in plants, from pure grapevine pixels in hyperspectral images. The Ψstem was acquired simultaneously in the field from bunch closure to harvest and modeled via machine-learning methods using the remotely sensed NIR-SWIR data as predictors in regression and classification modes (classes consisted of physiologically different water stress levels). Hyperspectral images were converted to bottom of atmosphere reflectance using standard panels on the ground and through the Quick Atmospheric Correction Method (QUAC) and the results were compared. The best models used data obtained with standard panels on the ground and allowed predicting Ψstem values with an R2 of 0.54 and an RMSE of 0.11 MPa as estimated in cross-validation, and the best classification reached an accuracy of 74%. This project aims to develop new methods for precisely monitoring and managing irrigation in vineyards while providing useful information about plant physiology response to deficit irrigation. [ABSTRACT FROM AUTHOR]

Maize is widely growth in arid and semi-arid region where, drought is common and a limiting factor for crop production. Potassium plays a key role in enhancing plant growth under drought condition. The objective of this study is to determine the effect of K fertilization with and without NP on maize growth grown in sandy loam soil under adequate and deficit irrigation conditions. The following treatments were investigated in pot experiment: (1) control with no fertilizer application (C); (2) 128 kg N + 328 kg P2O5 ha-1 (NPK0); (3) 128 kg N + 328 kg P2O5 ha-1 + 152.5 kg K2O ha1 (NPK1); (4) 128 kg N + 328 kg P2O5 ha-1 + 305 kg K2O ha-1 (NPK2); and 128 kg N + 328 kg P2O5 ha-1 + 457.5 kg K2O ha-1 (NPK3). Treatments were investigated under adequate and deficit soil moisture content. Each pot filled with 3.5 kg air-dry soil and seeded with maize and pots were watered according to the treatments. The results indicated that plant growth and nutrient uptake were significantly reduced under water stress condition. The application of NP increased plant growth and nutrient uptake and further were increased with K application. K application also enhanced plant tolerance to deficit soil moisture condition. In addition, K enhanced nutrient uptake and leaf chlorophyll content. Based on the results, it can be concluded that application of NP for maize was not adequate to achieve the highest plant growth, unless it is combined with K application. In addition, K application enhances plant tolerance to water stress. [ABSTRACT FROM AUTHOR]

The increase in crop yield can be primarily attributed to the combined effect of genetic advancements, as well as increased contributions from nitrogen (N) and water. The accumulation of dry matter plays a crucial role in determining grain yield in winter wheat. The current study aimed to better understand the source‐sink dynamics, analyse the dry matter transport (DMT) before and after anthesis and calculate its ratio to grain yield. In this experiment, eight main cultivars of winter wheat that have been widely cultivated in Shaanxi Province since the 1940s were selected as planting material. Field examinations were conducted using three levels of both irrigation and N. The yield‐related parameters, dry matter accumulation, dry matter distribution, DMT and DMT efficiency were measured. The results showed that irrigation prolonged the time of dry matter accumulation, and the application of N fertiliser increased the rate of dry matter accumulation. The analysis of the dynamic characteristic parameters of dry matter in winter wheat showed that irrigation and N had a significant impact on rate of dry matter accumulation. The proportion of stems, leaves and spikes of new varieties increased significantly (p < 0.05), which increased by 56.67%–69.7%, 13.26%–18.07% and 15.78%–28.26%, respectively, with the varietal improvement. The DMT efficiency increased with varietal improvement and also with increased irrigation and N application. The response of irrigation treatment to DMT and dry matter was more significant. In addition, the irrigation treatment had a higher effect on the DMT efficiency of vegetative organs after anthesis. The logistic equation analysis revealed that water stress accelerated the fulfilment of maximum daily temperature (Tmax), while both the maximum growth rate (Gmax) and dry matter weight (Wmax) decreased as water stress increased. There was a positive linear relationship between dry matter accumulation after anthesis and grain yield. The structural equation model showed that varieties, N application and irrigation had significant positive effects on DMT, post‐anthesis dry matter and grain yield, while irrigation had significant negative effects on DMT efficiency. The accumulation of dry matter in winter wheat after anthesis showed a significant increase with the succession of varieties. The combination of moderate deficit irrigation and fertilisation improved transportation and dry matter accumulation after anthesis in winter wheat, thereby enhancing its production capacity. [ABSTRACT FROM AUTHOR]

Soybeans are a crucial major food source in human and animal nutrition due to their high fat and protein content. This study investigated the effects of different irrigation methods on yield and yield components of second-crop soybeans under deficit irrigation conditions. The study aimed to determine the crop evapotranspiration, water productivity (WP), and irrigation water productivity (IWP) of the second crop soybean. The study followed a split plot random block experimental design with three replications. The main treatments of the study were subsurface drip irrigation (SDI), drip irrigation (DI), and furrow irrigation (FI) with four different water application levels (100%, 75%, 50%, and 25%) serving as subtreatments. Crop evapotranspiration (ETc) ranged between 236–482 mm for DI, 185–410 mm for SDI, and 275–562 mm for FI during 2018 and 2019. The yields for DI, SDI, and FI varied between 3,340–4,030 kg ha−1 , 3,250−3,780 kg ha−1 , and 2,800–3,680 kg ha−1 during 2018 and 2019, respectively. The effect of water deficit applications on yield was statistically significant at p<0.05 level. It was determined that the yield components of soybeans were negatively affected by deficit irrigation treatments, but the effect of different irrigation methods was not significant. There was no statistical difference between the treatment with 25% deficit irrigation and the full irrigation comparing the yield and yield components of the study. Moreover, WP and IWP values increased as the amount of irrigation water decreased in all irrigation methods. Thus, a 25% deficit is recommended as an alternative to full irrigation in the Mediterranean Basin when water resources are scarce. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the evaporation (E) and transpiration (T) components of evapotranspiration (ETc), and the growth parameters of curly lettuce (Lactuca sativa L. cv. Caipira) grown under different irrigation treatments. The study was conducted in a Mediterranean-type plastic greenhouse located in Antalya, Türkiye, in the fall and spring growing seasons of 2020 and 2021, respectively. To assess the impact of water stress on ETc and its components, three different irrigation water levels [ I100 for full irrigation treatment (100%), I66 for 66% (I100×0.66), and I33 for 33% (I100×0.33)] were selected. Planted and unplanted pots were used to measure ETc and E independently. The values obtained from these measurements were used as inputs to calculate the evaporation that occurred in the soil under the crop canopy and plant transpiration. In the present study, T was determined indirectly from the difference of measured evapotranspiration and evaporation and estimated with the modified Hernandez-Suarez model (Te). The modified model for the different irrigation treatments showed high Te estimation performance. Evaporation from the soil in the planted pots (Es) was calculated by considering the canopy cover and soil water content. The study revealed that water stress significantly affected lettuce plant height, root length, cover percentage, leaf area index (LAI), number of leaves, fresh and dry head weights, and root weights (p<0.01). The study also investigated the relationship between Es/ETc , and LAI using an exponential method and established a strong nonlinear relationship in all irrigation treatments (R2>0.90). The modified model developed for different irrigation treatments in Mediterranean-type greenhouses can be used to predict lettuce ETc values with greater precision and to better understand the partitioning of ETc into its constituent components. [ABSTRACT FROM AUTHOR]

The use of carbonaceous materials such as biochar has been considered an innovative solution in agriculture, especially to mitigate dry events caused by climate change. Biochar can improve water holding capacity, physical and chemical properties of soil, and increase the productivity of agricultural systems. However, underlying physiological mechanisms remain poorly understood. Mineral supplementation with potassium nitrate (KNO3) via foliar application is another promising strategy in agricultural management under irrigation deficit. Thus, we investigated the combined effects of biochar and foliar application of KNO3 on growth, yield, and physiology of tomato plants under different irrigation regimes. Results did not indicate a synergistic effect of biochar and foliar application of KNO3. Biochar application alleviated tomato plant stress under deficit irrigation, with plants showing better functioning of photosynthetic apparatus, higher yield, and better fruit quality, as well as increased water use efficiency. Coffee husk biochar (K-rich feedstock) fully met the tomato plant's demand for K and partially met the demand for some other elements (P, Mg, Fe, Zn, Mn, and Cu). Although positive effects of KNO3 application was verified for some physiological and fruit quality components, overall, foliar application of KNO3 did not improve tomato yield. It is concluded that biochar soil amendment can be a promising practice to increase yield and quality of tomato fruits under deficit irrigation. Therefore, biochar-based fertilizer can be an alternative K source that also provides stable carbon to soil and helps to mitigate stress caused by prolonged drought. [ABSTRACT FROM AUTHOR]

The extreme weather and the deteriorating water environment have exacerbated the crisis of freshwater resource insufficiency. Many studies have shown that salty water could replace freshwater to partly meet the water demand of plants. To study the effects of early-stage drought hardening and late-stage salt stress on tomatoes (Solanum lycopersicum L.), we conducted a 2-year pot experiment. Based on the multi-objective demands of high yield, high quality, and water saving, yield indicators, quality indicators, and a water-saving indicator were selected as evaluation indicators. Three irrigation levels (W1: 85% field capacity (FC), W2: 70% FC, W3: 55% FC) and three salinity levels (S2: 2 g/L, S4: 4 g/L, S6: 6 g/L) were set as nine treatments. In addition, a control treatment (CK: W1, 0 g/L) was added. Each treatment was evaluated and scored by principal component analysis. The results for 2022 and 2023 found the highest scores for CK, W2S2, W3S2 and CK, W2S4, W2S2, respectively. Based on response surface methodology, we constructed composite models of multi-objective demands, whose results indicated that 66–72% FC and 2 g/L salinity were considered the appropriate water–salt combinations for practical production. This paper will be beneficial for maintaining high yield and high quality in tomato production using salty water irrigation. [ABSTRACT FROM AUTHOR]

Copyright of Misr Journal of Agricultural Engineering is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Misr Journal of Agricultural Engineering is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Crops' water requirement is generally higher than the annual average precipitation in arid environments characterized by scarce freshwater resources. While using saline water for irrigation can help sustain agriculture in water-stressed regions, several challenges arises concerning productivity and soil salinization. However, adoption of efficient irrigation techniques such as drip irrigation, irrigation scheduling, and deficit irrigation can help optimize water productivity and mitigate salinity problems in irrigated agriculture. In southern Tunisia, potato is considered among the main cultivated horticultural crops due to its high economic value while it is considered as a crop sensitive to salinity. This crop (cv. Spunta) was the subject of long-term studies (2002-2020) conducted during the fall period in the arid region of Médenine. The crop response to full and deficit irrigation with saline water was assessed for several seasons under contrasting climatic conditions. Scheduling using the soil water balance (SWB) method consisted of the total and/or partial replacement of accumulated crop evapotranspiration (ETc), as derived from climatic data and crop coefficients. The impact of decreasing amounts of irrigation waters on crop yield and soil salinity with waters having a salinity ranging between 3 and 7 dS m-1 was evaluated. Results showed improvements in yield (30% to 37%) obtained with the SWB strategy under actual farming conditions, supporting the use of this strategy for irrigation. Appropriate scheduling also seems to be a key element in saving water (15%-22%) and in reducing risks of soil salinization. In the dry environment of southern Tunisia, optimum supply seems to correspond to a replacement of 100% to approximately 70%-80% of ETc. Applying such irrigation levels resulted in a lower salinity buildup in the root zone and higher crop water productivity. Natural salt leaching seems to be more effective under a more humid soil profile. Yield decreases and soil salinity increases almost linearly (r² = 0.60) with decreasing irrigation water amounts. Future work should focus on the integration of management practices when using saline water. Investigating the relationship and interaction between irrigation amounts, cultivar, fertilizer supply, and salt leaching will help in resolving productivity and environmental issues. [ABSTRACT FROM AUTHOR]

Jute, known as the 'Golden Fibre,' has been an intrinsic part of the Indian economy for centuries. India is the leading producer and exporter of jute, contributing to almost 70% of global production. However, the productivity of jute crops in India is often hampered by dry spells and erratic rainfall patterns. This article aims to explore the crucial role of dry spells on jute productivity and discuss ways to mitigate their negative impact through optimization of deficit irrigation water usages. An open-field experiment was carried out on jute cultivation under varying soil depletion of available moisture (DASM) and estimated crop water requirement (ETc) levels. The results of the study revealed that application of irrigation at '50% DASM with 75% ETc' or '75% DASM with 100% ETc' is beneficial to the crop during the pre-monsoon season for olitorius jute in alluvial soils of sub-tropical climate. The available soil-water regime at 100 to 50% soil water depletion produced the best fibre yield and water productivity. A yield increase of 23–44% was achieved with irrigation scheduling in comparison to the rainfed condition. Soil moisture, biomass, and canopy cover were all accurately simulated by the AquaCrop model. The study recommends deficit irrigation water usage as a method to reduce yield gaps and mitigate dry spells. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVES: The study explored the relationship between irrigation practices, water availability, and soil fertility in relation to crop yield. The investigation analyzed three distinct irrigation scenarios, namely full irrigation, deficit irrigation, and rain fed agriculture. The primary objective of the study was to evaluate the correlation between irrigation practices and soil fertility. To achieve this, the study incorporated different soil fertility levels, with high levels representing unlimited fertility for both full and deficit irrigation, and low levels corresponding to rain fed conditions. This design is primarily used to isolate the effects of irrigation practices on crop yields under a variety of fertility scenarios. The study also looks into how to achieve sustainable water management in the agricultural sector. METHODS: Aqua-crop, a computerized model, was utilized mimic real-life crop harvests. The aqua crop model was used to simulate crop yield in response to water availability. The calibration of the model involved utilizing data on various crop growth parameters, including soil fertility, crop canopy cover, evapotranspiration, soil water movement, crop yield and harvest index percentage. This innovative study utilizes aqua-crop to analyze the impact of irrigation methods on crop yields under controlled settings, effectively isolating irrigation influences from soil discrepancies. This approach is well-suited for studying sustainable water management strategies in agriculture, a pressing concern in light of worldwide water water scarcity. FINDINGS: Aqua-crop simulations revealed that consistent irrigation with a full irrigation system and high efficiency (70 percent) resulted in high yields. The simulated yields (8.48 to 10.04 tons per hectare) were significantly higher than farmers' actual yields (3.86 to 4.74 tons per hectare). Discrepancies between farmer irrigation methods and the model's assumption of uniform water application are the probable cause of the variation, underscoring the significance of considering real-world intricacies in the interpretation of model outcomes. The observed yield differences despite similar irrigation systems indicate the potential impact of unaccounted for factors such as soil type variations and real-world farmer practices (e.g., fertilization). Nevertheless, a substantial R-squared value of 0.85 suggests a robust association between simulated and observed yields, suggesting that aqua-crop can be valuable in comprehending overall irrigation-yield connections. Emphasis is placed on considering real-world complexities to achieve optimal crop yield. Aqua-crop simulations analyzed the correlation between irrigation and water use efficiency. Although full irrigation resulted in the highest simulated yields, deficit irrigation enhanced evapotranspiration water productivity. This seemingly contradictory finding can be explained by diminishing returns: deficit irrigation may result in slightly lower yields but higher water efficiency, highlighting the importance of considering both yield and water use efficiency when making long-term irrigation decisions. has highlighted the disparity between projected and actual crop yields, underscoring the significance of incorporating practical factors into the simulation of irrigation techniques. This finding holds particular relevance in areas where water resources are limited. CONCLUSION: The Food Agriculture Organization's aqua-crop is a useful tool for farmers who have limited access to water. Aqua-crop is a computer-based model that replicates the growth of crops in different irrigation scenarios. It provides farmers with the opportunity to explore the correlation between water usage and crop yield. By doing so, they can determine the most effective irrigation strategies that optimize harvest while minimizing water consumption. This aspect holds particular significance in regions facing water scarcity. [ABSTRACT FROM AUTHOR]

CITRUS is one of the most important fruit crops grown in the worldwide, especially in Mediterranean countries. Deficit irrigation (DI) is a proposed strategy many years ago to overcome the scarcity of water, especially in arid and semiarid regions. The vegetative growth, enzymatic activities, proline and phenolic content, fruit yield and quality in response to deficit irrigation levels (T1 (irrigation every 15 days as a control), T2 (irrigation every 20 days), T3 (irrigation every 25 days), and T4 (irrigation every 30 days), were evaluated. The results showed that the P, K, proline, phenols, vitamin C, SSC contents, and catalase and peroxidase activities were increased by T2 and T3. While the N content, fruit yield, weight, peel thickness, juice volume, and transpiration rate were increased by T1 and T2 compared to T3 and T4. The fruit yield, weight, and physical properties were not negatively affected by light and medium deficit irrigation (T2 and T3), which positively affected enzymatic activities, proline and phenol contents, and chemical fruit properties (SSC and Vitamin C). [ABSTRACT FROM AUTHOR]

Background: While water availability is important for quality at harvest, it also continues to influence the quality of pomegranates during storage. Reducing the amount of irrigation, in addition to water saving has different effects on bioactive compounds of pomegranate during storage time. This study was conducted to determine the influence of irrigation level on fruit quality changes during storage period of two commercial Iranian pomegranate cultivars ('Shishecap' and 'Malas-Yazdi'). Sustained deficit irrigation (SDI) was applied to plants that received 75% (moderate stress) or 50% (severe stress) of their normal water requirement. A control group received 100% of their water requirement. Results: At harvest time and during storage period, fruit weight loss and some biochemical traits such as fruit total soluble solids (TSS), titratable acidity (TA), pH, total phenolic compounds (TPC), total anthocyanins content (TAC), antioxidant activity and vitamin C were measured in pomegranate fruits. Also, the quantity of the produced product was also measured at the time of harvesting. Results indicated that control fruits exhibited more weight loss than those produced under water deficit during the storage period in both years. According to results, fruit TSS, TAC, and antioxidant activity significantly increased during storage period but fruit TA and vitamin C significantly decreased throughout storage period. Also, reduction in irrigation level resulted in a decline in the yield. Conclusions: This study revealed a crucial link between irrigation level and the quality of pomegranate fruits, despite a reduction in the yield. This included affecting weight loss and the content of bioactive compounds, both at harvest and during storage. [ABSTRACT FROM AUTHOR]

Nanoparticle-based methods can compensate for yield and quality loss of crops affected by drought. The current study, performed in a factorial experiment based on a completely randomized design, addressed to evaluate the effect of titanium dioxide nanoparticles (TiO2 NPs) at 0, 10, 20, and 30 mg L−1 under three irrigation regimes (full irrigation, partial root drying (PRD), and sustained deficit irrigation (SDI)) on Fragaria × ananassa cv. Camarosa. Results revealed that the PRD stress had more adverse effects on F. ananassa cv. Camarosa than SDI stress. Assessment of the behavior of TiO2 NPs in this study elucidated that mean productivity, yield stability index, and fruit number in plants grown under full irrigation increased when treated with 10 mg L−1 TiO2 NPs. Under the deficit irrigation, including PRD and SDI, all levels of TiO2 NPs mitigated mean productivity and yield stability index by ameliorating the fruit number and water use efficiency (WUE) and decreasing transpiration. Flowering and fruit set times were reduced by TiO2 NPs and deficit irrigation while their periods were enhanced by ones. It seems that when the strawberry was exposed to TiO2 NPs exhibited approximately drought tolerance. These nanoparticles ameliorated photosynthesis and mineral uptake and allocated dry matter to the root. These alterations can contribute to crop production in deficit irrigation strategies. [ABSTRACT FROM AUTHOR]

This study aims to develop an Artificial Neural Network (ANN) modeling to be trained to forecast the effects of different irrigation water levels and fertilizer doses on the hay yield and some quality traits of herbal parts of Sorghum × Sudan grass hybrid (Sorghum sudanense vs. Sorghum bicolor). The ANN model was developed on the limited field experiments implemented in Bilecik, Turkey, for 2 years in 2021 and 2022. Experiments were conducted in split-plot design with three replications. In the study, three irrigation levels (I100, I60, and I30) were placed in the main parcels, and four fertilizer levels (N0, N50, N100 and N150 kg ha−1) were placed in the sub-parcels. Irrigations were made in three critical periods according to the amount of cumulative evaporation occurring in the Class A Pan. The results showed that irrigation and fertilization are important in terms of yield and quality characteristics. The yield increased depending on the irrigation and fertilization dose, and the highest value was obtained from the I100 × N150 interaction (28.10 t ha−1). The highest protein yield was determined from the I60 × N150 (2.37 t ha−1) interaction, and the Relative Feed Value (RFV) value was determined from the I30 × N150 (92.17) interaction. Irrigation Water Use Efficiency (IWUE) and Water Use Efficiency (WUE) values increased with decreasing irrigation amount, and the highest IWUE was determined from I30 and the highest WUE was determined from I60 irrigation subjects. According to the field experiments and ANN model, the I80 irrigation with 100 kg ha−1 nitrogen doses would suit the feed yield and quality of Sorghum × Sudan grass hybrid. [ABSTRACT FROM AUTHOR]

Water scarcity, combined with low soil fertility, constitutes one of the main limiting factors in crop productivity in semi-arid regions. However, nutritional supplementation techniques with nitrogen (N) and molybdenum (Mo) can lead to positive enhancements in the production of these crops. The objective was to evaluate the effect of increasing doses of N in the presence and/or absence of Mo on the activity of antioxidant enzymes and the productive increase of forage sorghum subjected to water deficit in the semi-arid region. The experiment was conducted in the field using a randomized block design, with four replications, in a 5 × 2 × 3 factorial scheme, comprising five doses of N (urea): 0, 50, 100, 150, and 300 kg ha−1, two doses of Mo (sodium molybdate): 0 and 160 g ha−1, and three production cycles. The highest yields of green mass (GM) (47.98 Mg ha−1), dry mass (DM) (19.66 Mg ha−1), water use efficiency (WUE) (5.57 kg/m³), and N use efficiency (NUE) (0.26 kg2/g) occurred at the highest N dosage (300 kg ha−1 N). The highest contents and extraction of total N, Mo, chloride (Cl), and potassium (K) were found in regrowth 2 and at the highest N dose (300 kg ha−1). The interaction of N and Mo resulted in higher catalase (CAT) enzyme activity. The meteorological conditions during the cycles strongly influenced the nutrient contents and extraction. The results of the study provide support for producers to use N and Mo fertilization strategies to improve crop productivity, even under water deficit conditions. [ABSTRACT FROM AUTHOR]

Given the scarcity of arable land and water resources in semi-arid regions, it becomes imperative to achieve maximum yield and early maturity for winter grains. In this regard, the present research was conducted to synchronize grain and shoot maturity in high-yielding barley (cv. Behrokh) by reducing nitrogen and deficit irrigation. The experimental factors included three levels of nitrogen (50, 75, and 100% plant nitrogen requirement; PNR) and three levels of irrigation (full irrigation, cutoff irrigation in the milk stage, and dough stage). Results showed that cutoff irrigation and nitrogen fertilizer caused early ripening. The interactions of irrigation and nitrogen were significant for the number of grains/spike, grain yield, straw yield, aboveground biomass, and protein yield. Grain yield in cutoff irrigation in the dough stage plus reducing 25% PNR was similar to full irrigation plus 100% PNR. In full and cutoff irrigation in the dough stage, reducing 25% PNR did not cause a significant change in straw yield. Cutoff irrigation in the dough and milk stages did not cause a significant difference in the grain protein content. In general, it is concluded that to maintain grain, straw yield, and protein quality, it is more appropriate to use 150 kg/ha of nitrogen in the conditions of cutoff irrigation in the dough stage, which could reduce the cost of fertilizer and water in addition to early ripening of the crop and minimize the environmental consequences of consuming these inputs. Early harvesting of barley also helps to prevent summer crops from encountering late-season chilling. [ABSTRACT FROM AUTHOR]

Crop production is largely limited by water availability in arid and semi-arid regions of Ethiopia. Changing climate conditions and declining water resources demand appropriate approaches to improve crop yield and water use efficiency through a reduced and more reliable water supply. A field experiment was conducted to evaluate the effect of limited irrigation water use on bread wheat production and water use efficiency under the semi-arid climate conditions of Awash basin of Ethiopia. Five irrigation levels, that is, full irrigation (100% ETc/control), 85% ETc, 70% ETc, 55% ETc, and 40% ETc, were evaluated using a randomized complete block design (RCBD) with four replicates. Statistical analysis has shown a significant effect of irrigation levels on wheat grain yield, water use efficiency, economic profit, wheat grain quality, and aboveground biomass. The highest grain yield (5,085 kg ha−1) was obtained from 100% ETc irrigation application (i.e. 417.2 mm of water), and the lowest grain yield was obtained from 40% ETc (i.e. 223.7 mm of water) application. A deficit level of 85% ETc resulted in a yield that was comparable to that of full irrigation. Compared to other treatments, the 70% ETc application produced the highest water use efficiency (1.42 kg m−3). Using the saved water obtained from 70% ETc deficit irrigation application, 23.4% more wheat could be produced on 1.38 ha of land, resulting in the highest profit (US$2,563.9) and higher MRR (137%). The yield response factor and crop-water production function indicated that maintaining irrigation at optimal levels can prevent potential yield reductions. Consequently, a 70% ETc deficit irrigation application was found to be optimal for increasing wheat grain yield, water use efficiency, and economic benefits from irrigated wheat production. These results suggest that deficit irrigation for wheat under semi-arid climatic conditions is a viable irrigation management option for enhancing water use efficiency. [ABSTRACT FROM AUTHOR]

With the increasing world population, global warming, and climate change, water scarcity significantly limits water use in crop production. Therefore, timely and accurate determination of water stress is very important for the correct and effective management of existing water resources and minimizing harmful effects on crop production. Two years of experiments were conducted in the water-limited region in Türkiye to investigate the possible use of the Crop Water Stress Index (CWSI) as a remote sensing technology in sugar beet irrigation scheduling. Four different Irrigation levels (I50: 50% deficit, I75: 25% deficit, I100: full irrigation, and I125: 25% excess irrigation) were applied to sugar beet by drip irrigation system. The amount of applied irrigation water and crop evapotranspiration varied between 238-540 and 350-580 mm in 2021, and between 324- 807 and 502-829 mm in 2022. In both years, the highest beed yields were obtained from I100 treatments (83 and 130 t ha-1) and the lowest from I50 treatments (66.7 and 67.4 t ha-1). Water Productivity (WP) and Irrigation Water Productivity (IWP) in both years decreased significantly by excessive irrigation. CWSI values ranged between 0.16-0.98 in 2021 and between 0.02-0.71 in 2022. CWSI was significantly related to yield and Leaf Area Index (LAI). According to the results, CWSI could be used successfully in sugar beet irrigation scheduling and yield estimation. [ABSTRACT FROM AUTHOR]

Secondary growth in garlic depreciates its visual aspect and thereby renders the crop unviable for trade. Therefore, farmers commonly reduce fertilization and impose drought and oxidative stress caused by high-dose pesticides to reduce secondary growth in garlic plants. However, these procedures can be considered adverse, unhealthy, and environmentally inappropriate. To remedy this scenario, we investigated whether spraying growth inhibitors would prevent secondary growth in garlic plants. First, we evaluated the effects of abscisic acid, trinexapac-ethyl, chlormequat chloride, and paclobutrazol treatments on garlic plants grown in polyethylene tanks (250 m3). We then analyzed the effects of deficit irrigation combined with the application of trinexapac-ethyl (sprayed two or three times) and the application of trinexapac-ethyl, chlormequat chloride, or paclobutrazol alone (each sprayed two or three times) on garlic plants grown in the field, comparing them with the effects of deficit irrigation (control treatment) alone. The in-field experiment was replicated with the following treatments: control (deficit irrigation) and trinexapac-ethyl (sprayed two or three times) treatments. We analyzed the physiological, biometric, and production parameters affecting secondary growth in garlic plants. We observed that trinexapac-ethyl could efficiently regulate secondary growth without causing physiological disturbances in garlic plants. Our results provide valuable information that will contribute to the development of a sustainable technique to replace the current practices used by farmers to prevent secondary growth in garlic plants. [ABSTRACT FROM AUTHOR]

The combined application of biochar and fertilizer has become increasingly popular for improving soil quality and crop productivity. However, the reported research results regarding the effects of biochar on soil properties and crop productivity have contradictory findings, indicating the requirement for further scientific research. Therefore, this study aimed to investigate the effects of a combined application of water hyacinth biochar (WHB) and NPS fertilizer on soil physicochemical properties and wheat yield under deficit irrigation conditions in acidic silty loam soil in Ethiopia. Four different biochar rates (0, 5, 10, and 20 t ha−1), three fertilizer rates (0, 100, and 200 kg NPS ha−1), and two irrigation regimes (50 and 100% of crop requirement) were evaluated to assess soil properties and wheat yields. The results showed that biochar amendment significantly reduced soil bulk density by 15.1–16.7%, and improved soil porosity by 6.8–8.6% and moisture content by 10.3–20.2%. Additionally, the combined application of biochar and fertilizer improved soil pH (0.26–0.87 units), NH4+–N (73.7–144%), NO3−–N (131–637%), and available phosphorus (85.8–427%), compared to the application of fertilizer alone. As a result, wheat dry biomass and grain yield increased by 260 and 173%, respectively. Furthermore, the combined application of WHB and fertilizer resulted in a comparable wheat dry biomass and grain yield even with a 50% reduction of irrigation water. Therefore, WHB has a significant potential to improve soil physicochemical properties and wheat yield when it is applied in combination with fertilizer, and it can reduce the water requirement for wheat production. [ABSTRACT FROM AUTHOR]

Water-saving irrigation is of extraordinary importance for tomato production in semi-arid areas of northwest China. For this purpose, we conducted a two-season trial in a solar greenhouse of two tomato genotypes named '181' and 'Mao Fen 802' and cultivated with substrate, under four irrigation regimes, i.e., well-watered (WW), low (LWD, 80% WW), moderate (MWD, 60% WW) and high (HWD, 40% WW) water deficit. The substrate water content of WW treatment was 75%θf to 90%θf (where θf is the field capacity). The study results showed that the single fruit weight and yield of tomato were significantly declined with an increasing water deficit degree. Compared to WW treatment, the fruit weight and yield were decreased about 34.45% and 20.35% for '181' and 'Mao Fen 802' under HWD treatment, respectively. Conversely, water deficit treatment led to an obvious promotion of WUE and showed an upward trend as the water deficit level increased. In addition, compared to WW treatment, the water deficit significantly decreased the total flavonoids of the '181' tomato by 24.4–93.1%, whereas there was no significant impact on that of 'Mao Fen 802'. Nonetheless, different individual polyphenols were increased by suitable deficit irrigation for two tomato cultivars. Gallic acid, 3,4-dihydroxybenzoic acid, and naringin of '181'tomato were increased by 128.4–195.2%, 8.6–43.7%, and 31–73-fold, respectively, under water deficit compared to WW treatment. Further, under water deficit treatment, p-coumaric acid, benzoic acid, and 3,4-dihydroxybenzoic acid of 'Mao Fen 802' were increased by 36.2–49.2%, 59.1–189.7%, and 36.3–106.4% compared to WW treatment. As the main carotenoid component, the lycopene content of tomato fruit exhibited a significant rise of 7.84–20.02% and 20.55–32.13% for '181' and 'Mao Fen 802' under three degrees of water deficit compared to WW treatment. Linear regression showed a significantly positive relationship between irrigation amounts and yield, and total polyphenols, whereas there was a significantly negative relationship between irrigation amounts and WUE, and total carotenoids. Based on correlation and PCA, WW and LWD, and MWD and HWD, were gathered together for '181', while LWD, MWD, and HWD, were gathered, and only WW scattered for 'Mao Fen 802', along the PC1 direction. It was proposed that 'Mao Fen 802' was more sensitive to water deficit than the '181' tomato. In conclusion, water deficit is conductive to water-saving cultivation of the greenhouse tomato and the tomato genotypes, and water deficit level is a key factor necessary for consideration. [ABSTRACT FROM AUTHOR]

Almond cultivation has a long-standing tradition on the island of Majorca, traditionally practiced under rainfed conditions. Currently, new plantations are established with irrigation; however, due to present conditions and the impacts of climate change, water availability is limited. The Government of the Balearic Islands permits a maximum water supply of 3000 m3 ha−1 per year for almond cultivation. In this study, a 6-year field trial was conducted to investigate the adaptation of fourteen almond cultivars obtained from different research centers under deficit irrigation practices in the soil and climatic conditions of Majorca Island. The cultivars had a significant effect on trunk cross-sectional area TCSA, cumulative almond in-shell yield, cumulative kernel yield, yield efficiency, and shelling percentage. The 'Marta' and 'Tarraco' cultivars exhibited the highest TCSA values. Regarding cumulative almond in-shell yield, 'Glorieta' and 'Constantí' produced the highest yields, whereas the lowest yields were observed in 'Mardía' and 'Tarraco'. In terms of shelling percentage, 'Ferragnès' exhibited the highest value. Kernel quality parameters were cultivar-specific. Additionally, oleic acid content was strongly negatively correlated with linoleic acid content. All cultivars exhibited an unsaturated fatty acid content exceeding 90%, with 'Masbovera' showing the highest value. [ABSTRACT FROM AUTHOR]

The optimization of plant density plays a crucial role in cotton production, and deficit irrigation, as a water-saving measure, has been widely adopted in arid regions. However, regulatory mechanisms governing nitrogen absorption, transportation, and nitrogen use efficiency (NUE) in cotton under deficit irrigation and high plant density remain unclear. To clarify the mechanisms of N uptake and NUE of cotton, the main plots were subjected to three irrigation amounts based on field capacity (Fc): (315 [W1, 0.5 Fc], 405 [W2, 0.75 Fc, farmers' irrigation practice], and 495 mm [W3, 1.0 Fc]). Subplots were planted and applied at three densities: (13.5 [M1], 18.0 [M2, farmers' planting practice], and 22.5 [M3] plants m−2). The results revealed that under low-irrigation conditions, the cotton yield was 5.1% lower than that under the farmer's irrigation practice. In all plant densities and years, the nitrogen uptake of cotton increased significantly with the increase in irrigation. However, excessive irrigation resulted in nitrogen accumulation and migration, mainly concentrated in the vegetative organs of cotton, which reduced the NUE by 9.2% compared with that under farmers' irrigation practice. Concerning the interaction between irrigation and plant density, under low irrigation, the nitrogen uptake of high-density planting was higher, and the yield of seed cotton was only 2.9% lower than that of the control (the interaction effect of farmers' irrigation × plant density), but the NUE was increased by 10.9%. Notably, with the increase in irrigation amount, the soil nitrate nitrogen at the 0–40 cm soil layer decreased, and high irrigation amounts would lead to the transfer of soil nitrate nitrogen to deep soil. With the increase in plant density, the rate of nitrogen uptake and the amount of nitrogen uptake increased, which significantly reduced the soil nitrate nitrogen content. In conclusion, deficit irrigation and high plant density can improve cotton yield and NUE. We anticipate that these findings will facilitate optimized agricultural management in areas with limited water. [ABSTRACT FROM AUTHOR]

High-density olive groves, despite their interesting production potential, have several limitations, including their high fruit load and irrigation requirements. This study aimed to evaluate the effects of fruit load and deficit irrigation on oil yield, fruit quality, and olive chemical composition in a high-density olive grove (cv Sikitita). Our main hypothesis was that primary metabolism, as influenced by crop load and stress, could modify the accumulation of different phenolic classes. Different fruit loads were generated through flower thinning (66%, 50%, 33%, 0%), and two deficit irrigation treatments (−60%, −75%) were compared to the well-watered control (920 m3/ha). Thinning treatments had a limited effect on oil yield; on the other hand, deficit irrigation caused considerably less oil accumulation in the fruit on all sampling dates. Thinning 66% and deficit irrigation 75% were considered with the control for untargeted metabolomic analysis, including three sampling dates. A total of 233 distinct phenolic compounds were annotated. Multivariate HCA results indicated that harvest time had an impact on the phenolic profile of olive fruits, obtaining two separated clusters that grouped t1 and t2 together and apart from t3, which clustered independently. Regarding agronomic techniques, they played a differential role in the phenolic profile (supervised OPLS-DA). Fruit load mostly affected flavonoid glycosides. In contrast, the phenolic response to deficit irrigation was more heterogeneous, with phenolic acids (35%), flavonoids (25%), LMW, and other phenols (25%). [ABSTRACT FROM AUTHOR]

Salicylic acid (SA) and melatonin (MEL) are affordable and effective phytohormones that help mitigate environmental stress. However, the combined benefits of SA and MEL in managing salt and drought stress in lettuce have not been evaluated. Therefore, this study was designed to evaluate the effectiveness of foliar spraying with 1.0 mM SA and 100 µM MEL, either alone or in combination, to enhance lettuce yield, growth, photosynthetic pigments, mineral status, quality, and antioxidant response under four different irrigation regimes. The irrigation practices used were: full irrigation (FI, irrigated with 0.18 dS m −1 at 100 % field capacity [FC]), deficit irrigation (DI, irrigated with 0.18 dS m −1 at 75 % FC), saline irrigation (SW, irrigated with 2.5 dS m −1 at 100 % FC), and deficit saline irrigation (DSW, irrigated with 2.5 dS m −1 at 75 % FC). Additionally, a control treatment (CK) was carried out with foliar application of distilled water and irrigation at 0.18 dS m −1. Compared to the CK, the application of SA, MEL, and SA+MEL increased evapotranspiration by 4.3 %, 8.6 %, and 15.1 %, and yield by 10.2 %, 16.4 %, and 23.8 %, respectively, under FI conditions. Furthermore, the joint application of SA and MEL at FI showed 25.3 % and 20.2 % higher K +/Na+ and Ca2+/Na+ ratios, respectively, compared to the CK. Additionally, the co-application of SA+MEL improved chlorophyll a, b, and carotenoid levels by 19.2 %, 17.2 %, and 20.4 %, respectively, under FI conditions, compared to the CK. Exogenous application of SA, MEL, and SA+MEL also improved total soluble solids by 17.3 %, 18.5 %, and 11.1 % and reduced nitrate content by 9.7 %, 10.4 %, and 13.5 % in lettuce under FI conditions, compared to the CK. The application of SA+MEL together resulted in a more pronounced increase in vitamin C content compared to supplying SA and MEL individually. Moreover, under DSW conditions, exogenous application of SA, MEL, and SA+MEL decreased the membrane stability index by 13.7 %, 9.4 %, and 6.3 %, increased malondialdehyde by 65.4 %, 40.8 %, and 36.6 %, and increased proline content by 68.4 %, 65.4 %, and 96.4 %, respectively, compared to the CK. Moreover, exogenous SA+MEL significantly increased the activities of superoxide dismutase, catalase, peroxidase enzymes under both SW and DSW conditions compared to the SA or MEL. Conversely, the activity of ascorbate peroxidase enzyme showed a gradual decrease in DI, SW, and DSW conditions, relative to the FI conditions. In conclusion, the integrated application of SA+MEL is an optimal strategy to enhance yield, morpho-physiological traits, nutrient homeostasis, antioxidant capacity, and quality in lettuce and mitigate the adverse effects of drought, salinity, and drought-salinity stress. [Display omitted] • Deficit saline irrigation has the most adverse effect on lettuce yield. • SA and MEL enhanced lettuce tolerance to drought and salinity stress. • Joint use of SA (1.0 mM) and MEL (100 µM) more effectively alleviates stress in lettuce. • SA+MEL improved the nutrient homeostasis and antioxidant capacity of lettuce. • SA+MEL combination increased vitamin C and decreased the nitrate content of lettuce. [ABSTRACT FROM AUTHOR]

Jojoba (Simmondsia chinensis) is cultivated for its seeds, which contain a high-value liquid wax. There is little known regarding irrigation requirements of intensively cultivated jojoba. The project's objectives were to evaluate the effects of irrigation regime on water status, growth, yield, and water productivity (WP, wax yield per unit of water applied) of intensely cultivated jojoba. An experiment was conducted over six years in a 14-year-old commercial plantation in Israel's Northern Negev Desert. Treatments included: Control irrigation according to best commercial practice of returning reference evapotranspiration multiplied by a crop coefficient (Kc) of 0.5; Low irrigation providing 75% (Kc = 0.375) of the control; High irrigation providing 125% (Kc = 0.625) of the control; Regulated deficit irrigation (RDI) according to the control treatment, terminated for one to two months, after the wax accumulation stage. Stem water potential (SWP) consistently indicated jojoba water status. Increasing water application from − 25% to the control and further to + 25% led to augmented vegetative growth and number of seeds, but yield was increased at rates lower than the differences in water application by the treatments, such that WP was negatively associated. Effects on yield were limited to higher yielding 'On' years. The RDI treatment resulted in yield not different from the control and 15% higher WP, but significantly inhibited seed removal during mechanical harvesting. The results suggest commercial potential for increasing profits through water savings. Further research is needed to determine RDI regimes without detrimental effects on harvesting efficiency. [ABSTRACT FROM AUTHOR]

To better understand the implications of climate change, the combined responses of olive trees to irrigation amount and warming need to be examined. Thus, the objective was to evaluate the effects of moderate deficit irrigation and warming during late winter and spring on vegetative growth and biomass, full bloom timing and intensity, and yield components in young olive trees. Two three month-long experiments were conducted using open top chambers with four treatment combinations: 100% irrigation with a control temperature; 100% irrigation with 4 °C warming; 50% irrigation with a control temperature; and 50% irrigation with 4 °C warming. The trees were potted two-year-old, cv. Arbequina trees in the 2018 experiment and three-year-old, cv. Coratina trees in the 2019 experiment. Flowering was low in the young cv. Arbequina trees in 2018, but it was much greater in the older cv. Coratina trees in 2019. Overall, lower flowering intensity and fruit set or more parthenocarpic fruit contributed to less viable fruit number with warming. These reproductive variables were less affected by deficit irrigation. In contrast, shoot growth and vegetative biomass were decreased by deficit irrigation in cv. Arbequina (2018) when fruit number was low in all trees with less response due to warming. In cv. Coratina (2019), the lower fruit number in warmed compared to control trees contributed to greater individual fruit weight at the end of the experimental period, and few significant effects of either deficit irrigation or warming on shoot growth were observed. Fruit yield was greater in the well-irrigated, temperature control than in the other treatment combinations in cv. Arbequina, while warming reduced fruit yield in cv. Coratina. From a production perspective, it does not appear that many early reproductive responses to warming can be easily counteracted by adjusting irrigation. Further studies with more mature trees and cultivars over several growing seasons are recommended. [ABSTRACT FROM AUTHOR]

Super-high density olive orchards may increase profitability for table olive producers. However, water needs and fruit damage could limit their viability. Deficit irrigation scheduling would reduce the amount of water required, but rehydration before harvest is extremely important. The aim of this work was to compare a typical deficit farm management model with a regulated deficit irrigation one based on the plant water status. The experiment was carried out during three seasons in a three years-old (4 × 1.5 m) commercial table olive orchard. In both irrigation scheduling plots, seasonal amount of applied water was similar. Irrigation treatments were: common farm management (CFM), an almost constant rate of irrigation, and Regulated deficit (RDI) based on midday shaded water potential. Vegetative measurements suggested that RDI increased the external surface of the hedge, and this was related with greater yield in this treatment. Significant differences were found in of fruit size at harvest in some seasons, with larger fruits in RDI compared to CFM. However, fruit damage occurred during mechanical harvest in both irrigation managements, despite the higher skin firmness in RDI, and shows the need to carry out postharvest treatments to improve the quality of the final product. Accurate control of the tree water status would allow optimizing the amount of water available for table olive orchards. [ABSTRACT FROM AUTHOR]

Climate change represents one of the current major challenges and the improper use of water resources is an impeding threat. Agricultural research can play a crucial role by developing innovative strategies and techniques to reduce water use without affecting crop productivity and quality, particularly in grapevine growing in Mediterranean areas, as both productivity and wine quality are quintessential for the economic and ecologic sustainability of this crop. The present study aimed to define a deficit irrigation strategy for the "Primitivo" grapevine cultivar, taking into account the overall pathway of the vineyard performance in terms of leaf functionality, starch reserves, vine productivity, and wine quality. The trial was carried out in Southern-Italy on a three year-old, drip irrigated vineyard, imposing four deficit irrigation regimes for two consecutive seasons, consisting of 29 (T29), 55 (T55), 85 (T85) and 100% (T100) of crop evapotranspiration (ETC). Mild water restriction (T85) did not affect vegetative nor reproductive vine performance. Deficit irrigation at 55% ETC lowered leaf functionality, starch accumulation, vine vigour and yield, due to a reduction of cluster weight; however, wine acidity and phenolic compounds were increased. T29 further decreased yield, as also the number of clusters was reduced. The most water-stressed treatment revealed a low concentration of malic acid in the must and a consequent increase of the ethanol sensation in the wine. After 9 months ageing, T85 had the highest wine colour intensity suggesting this treatment as the most promising in terms of quality and quantity of wine as well as for water saving. [ABSTRACT FROM AUTHOR]

The olive tree (Olea europaea L.) is culturally and economically vital in Morocco. However, its sustainability is threatened by aridity and water scarcity. Studying its response to different irrigation strategies is crucial for sustainable cultivation and improved water use efficiency in the face of future drought events. This work aimed to study the responses of sap flow rate, physiological, and agronomic parameters of the Moroccan olive cultivar 'Menara' to Regulated Deficit Irrigation (RDI) and Sustained Deficit Irrigation (SDI) strategies. Seven irrigation regimes were studied based on the sensitivity of phenological phases to water stress, distinguished as (SP) 'Sensitive Period' and (NP) 'Normal Period'. SP involves flowering (SP1) and oil synthesis to harvest (SP2), while NP relates to pit hardening. 'Menara' olive trees were subjected to four RDI treatments: T1 (SP 100- NP 70% ETc), T2 (SP 100- NP 60% ETc), T3 (SP 80- NP 70% ETc), and T4 (SP 80- NP 60% ETc), and two SDI treatments: T5 (70% ETc) and T6 (60% ETc), compared with control (T0) trees under full irrigation (100% ETc). In comparison to the control T0, the deficit irrigation treatments exhibited lower sap flow rates. Specifically, T1 and T2 experienced reductions of 10% and 19% in sap flow rates, respectively, attributed to a decrease in water application of 11% and 14% compared to T0. Despite this decline, T1 and T2 demonstrated fruit yields comparable to T0. Conversely, T4, which received 28% less irrigation, displayed a yield reduction of approximately 23% compared to T0 in 2022. Moreover, adverse effects were observed in Menara olive trees treated with T4 after two consecutive seasons of deficit irrigation in 2023, indicating that prolonged stress effects could be detrimental in subsequent years. T3, under RDI, showed resilience with a 13% reduction in production despite a 37% decrease in sap flow rate and a 24% water restriction. Conversely, T5 and T6, employing SDI, experienced significant yield declines of 50%, with reductions in water application of 30% and 40% and sap flow rate of 51% and 80%, respectively, in 2022. The alternate bearing pattern significantly impacts Menara olive production, as evidenced by reduced sap flow and yield in the "off" year of 2023, regardless of irrigation strategies. A strong correlation (R2 = 0.84) between sap flow and yield indicates that well-irrigated olive trees tend to transpire more, leading to higher yields. Stomatal conductance (gs) notably decreases with increased water deficit, with reductions of 8%, 12%, and 23% observed in T4, T5, and T6, respectively. Furthermore, a significant reduction in FV/FM, indicative of water stress, was observed with a 40% decrease in water supply in the T6 treatment group during both irrigation seasons in 2022 and 2023, with Fv/Fm reaching approximately 0.7. In general, Menara olive trees subjected to deficit irrigation, particularly under the T3 RDI treatment, showed the ability to adapt and cope with low water supply over time. However, the cumulative water shortage effect of the SDI treatment T6 resulted in a decline in both the agronomic and physiological performance of this cultivar. [ABSTRACT FROM AUTHOR]

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Green peppers (Capsicum annuum L.) are a fruit vegetable with great culinary versatility and present important nutritional properties for human health. Water deficit negatively affects the nutritional quality of green peppers' fruits. This study aimed to investigate the influence of zinc oxide nanoparticles (ZnONPs), associated with plant growth-promoting bacteria (PGPB), on the post-harvest nutritional quality of green peppers subjected to water deficit. In an open-field experiment, two irrigation levels (50 and 100% of crop evapotranspiration (Etc)), four treatments composed of a combination of ZnONPs, zinc sulfate (ZnSO4), and PGPB (T1 = ZnSO4 via leaves, T2 = ZnONPs via leaves, T3 = ZnONPs via leaves + PGPB via soil, T4 = ZnSO4 via soil + PGPB via soil), and a control treatment (Control) were tested. Water deficit or water deficit mitigation treatments did not interfere with the physical–chemical parameters (except vitamin C content) and physical color parameters (except the lightness) of green peppers. On average, the water deficit reduced the levels of Ca (−13.2%), Mg (−8.5%), P (−8.5%), K (−8.6%), Mn (−10.5%), Fe (−12.2%), B (−12.0%), and Zn (−11.5%) in the fruits. Under the water deficit condition, ZnONPs or ZnSO4 via foliar, associated or not with PGPB, increased the levels of Ca (+57% in the T2 and +69.0% in the T2), P, Mg, and Fe in the fruits. At 50% Etc, the foliar application of ZnONPs in association with PGPB increases vitamin C and mineral nutrients' contents and nutritional quality index (+12.0%) of green peppers. Applying Zn via foliar as ZnONPs or ZnSO4 mitigated the negative effects of water deficit on the quality of pepper fruits that were enhanced by the Bacillus subtilis and B. amyloliquefaciens inoculation. The ZnONPs source was more efficient than the ZnSO4 source. The water deficit alleviating effect of both zinc sources was enhanced by the PGPB. [ABSTRACT FROM AUTHOR]

Water is crucial for enduring horticultural productivity, but high water-use requirements and declining water supplies with the changing climate challenge economic viability, environmental sustainability, and social justice. While the scholarly literature pertaining to water management in horticulture abounds, knowledge of practices and technologies that optimize water use is scarce. Here, we review the scientific literature relating to water requirements for horticulture crops, impacts on water resources, and opportunities for improving water- and transpiration-use efficiency. We find that water requirements of horticultural crops vary widely, depending on crop type, development stage, and agroecological region, but investigations hitherto have primarily been superficial. Expansion of the horticulture sector has depleted and polluted water resources via overextraction and agrochemical contamination, but the extent and significance of such issues are not well quantified. We contend that innovative management practices and irrigation technologies can improve tactical water management and mitigate environmental impacts. Nature-based solutions in horticulture—mulching, organic amendments, hydrogels, and the like—alleviate irrigation needs, but information relating to their effectiveness across production systems and agroecological regions is limited. Novel and recycled water sources (e.g., treated wastewater, desalination) would seem promising avenues for reducing dependence on natural water resources, but such sources have detrimental environmental and human health trade-offs if not well managed. Irrigation practices including partial root-zone drying and regulated deficit irrigation evoke remarkable improvements in water use efficiency, but require significant experience for efficient implementation. More advanced applications, including IoT and AI (e.g., sensors, big data, data analytics, digital twins), have demonstrable potential in supporting smart irrigation (focused on scheduling) and precision irrigation (improving spatial distribution). While adoption of technologies and practices that improve sustainability is increasing, their application within the horticultural industry as a whole remains in its infancy. Further research, development, and extension is called for to enable successful adaptation to climate change, sustainably intensify food security, and align with other Sustainable Development Goals. [ABSTRACT FROM AUTHOR]

The impact of the intercropping system on the soil–plant–atmosphere continuum (SPAC), encompassing soil evaporation, soil moisture dynamics, and crop transpiration, remains an area of uncertainty. Field experiments were conducted for two years in conjunction with the SIMDualKc (Simulation Dual Crop Coefficient) model to simulate two planting configurations: sole-cropped wolfberry (Lycium barbarum L.) (D) and wolfberry intercropped with alfalfa (Medicago sativa L.) (J). These configurations were subjected to different irrigation levels: full irrigation (W1, 75–85% θfc), mild deficit irrigation (W2, 65–75% θfc), moderate deficit irrigation (W3, 55–65% θfc), and severe deficit irrigation (W4, 45–55% θfc). The findings revealed that the JW1 treatment reduced the annual average soil evaporation by 32% compared with that of DW1. Additionally, mild, moderate, and severe deficit irrigation reduced soil evaporation by 17, 24, and 36%, respectively, compared with full irrigation. The intercropping system exhibited a more efficient canopy structure, resulting in reduced soil evaporation and alleviation of water stress to a certain extent. In terms of temporal dynamics, monocropping resulted in soil moisture levels from 1% to 15% higher than intercropping, with the most significant differences manifesting in the mid to late stages, whereas differences in the early stages were not statistically significant. Spatially, the intercropping system exhibited 7–19% lower soil water contents (SWCs) than sole cropping, primarily within the root water uptake zone within the 0–60 cm soil layer. The intercropping system showed an enhanced water absorption capacity for plant transpiration, resulting in a 29% increase in transpiration compared with sole cropping, thereby achieving water-saving benefits. These findings contribute to our understanding of the agronomic and environmental implications of intercropping wolfberry and alfalfa in arid regions and provide insights into optimizing water and soil resource management for sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

Atmospheric elevated CO2 concentration (e[CO2]) decreases plant nitrogen (N) concentration while increasing water use efficiency (WUE), fertigation increases crop nutrition and WUE in crop; yet the interactive effects of e[CO2] coupled with two N-fertigation levels during deficit irrigation on plant gas exchange, root morphology and WUE remain largely elusive. The objective of this study was to explore the physiological and growth responses of ambient [CO2] (a[CO2], 400 ppm) and e[CO2] (800 ppm) tomato plant exposed to two N-fertigation regimes: (1) full irrigation during N-fertigation (FIN); (2) deficit irrigation during N-fertigation (DIN) under two N fertilizer levels (reduced N (N1, 0.5 g pot−1) and adequate N (N2, 1.0 g pot−1). The results indicated that e[CO2] associated with DIN regime induced the lower N2 plant water use (7.28 L plant−1), maintained leaf water potential (−5.07 MPa) and hydraulic conductivity (0.49 mol m−2 s−1 MPa−1), greater tomato growth in terms of leaf area (7152.75 cm2), specific leaf area (223.61 cm2 g−1), stem and total dry matter (19.54 g and 55.48 g). Specific root length and specific root surface area were increased under N1 fertilization, and root tissue density was promoted in both e[CO2] and DIN environments. Moreover, a smaller and denser leaf stomata (4.96 µm2 and 5.37 mm−2) of N1 plant was obtained at e[CO2] integrated with DIN strategy. Meanwhile, this combination would simultaneously reduce stomatal conductance (0.13 mol m−2 s−1) and transpiration rate (1.91 mmol m−2 s−1), enhance leaf ABA concentration (133.05 ng g−1 FW), contributing to an improvement in WUE from stomatal to whole-plant scale under each N level, especially for applying N1 fertilization (125.95 µmol mol−1, 8.41 µmol mmol−1 and 7.15 g L−1). These findings provide valuable information to optimize water and nitrogen fertilizer management and improve plant water use efficiency, responding to the potential resource-limited and CO2-enriched scenario. [ABSTRACT FROM AUTHOR]

The management of invasive plants is a challenge when using traditional control methods, which are ineffective for large areas, leading to the abandonment of invaded areas and the subsequent worsening of the situation. Finding potential uses for waste resulting from invaders' management could motivate their control in the long-term, concurrently providing new bio-based resources with different applications. Oxalis pes-caprae is an invasive plant, widely distributed worldwide, which spreads aggressively through bulbils, creating a dense ground cover. This study was designed to assess the potential of Oxalis aboveground waste for use as fertilizer and in ameliorating deficit irrigation effects in growing crops. Diplotaxis tenuifolia (wild rocket) seedlings were planted in pots with soil mixed with Oxalis waste at 0, 2.2 and 4.3 kg m−2 or with commercial fertilizer, left to grow for 27 days and then irrigated at 100% or 50% field capacity for 14 days. The incorporation of the Oxalis waste improved the biomass, photosynthesis, sugars, total phenols and total antioxidant capacity in the crop, achieving commercial fertilization values, as well as increasing the phosphorus in soils. However, Oxalis waste seems not to directly affect plants' relative water contents. Our results support the use of Oxalis waste as fertilizer, which can encourage the long-term control of this invasive species. [ABSTRACT FROM AUTHOR]

Crop coefficient (Kc), the ratio of crop evapotranspiration (ETc) to reference evapotranspiration (ETo), is used to schedule an efficient irrigation regime. This research was conducted to investigate variations in ETc and growth-stage-specific Kc in flood-irrigated winter wheat as a forage crop from 2021 to 2023 in the Lower Rio Grande Valley of southern New Mexico, USA, and evaluate the performances of two temperature-based ETo estimation methods of Hargreaves–Samani and Blaney–Criddle with the widely used Penman–Monteith method. The results indicated that the total ETc over the whole growth stage for flood-irrigated winter wheat was 556.4 mm on a two-year average, while the average deep percolation (DP) was 2.93 cm and 2.77 cm, accounting for 28.8% and 27.2% of applied irrigation water in the 2021–2022 and 2022–2023 growing seasons, respectively. The ETo over the growing season, computed using Penman–Monteith, Hargreaves–Samani, and Blaney–Criddle equations, were 867.0 mm, 1015.0 mm, and 856.2 mm in 2021–2022, and 785.6 mm, 947.0 mm, and 800.1 mm in 2022–2023, respectively. The result of global sensitivity analysis showed that the mean temperature is the main driving factor for estimated ETo based on Blaney–Criddle and Hargreaves–Samani methods, but the sensitivity percentage for Blaney–Criddle was 76.9%, which was much higher than that of 48.9% for Hargreaves–Samani, given that Blaney–Criddle method is less accurate in ETo estimation for this area, especially during the hottest season from May to August. In contrast, wind speed and maximum temperature were the main driving factors for the Penman–Monteith method, with sensitivity percentages of 70.9% and 21.9%, respectively. The two-year average crop coefficient (Kc) values at the initial, mid, and late growth stage were 0.54, 1.1, and 0.54 based on Penman–Monteith, 0.51, 1.0 and 0.46 based on Blaney–Criddle, and 0.52, 1.2 and 0.56 based on Hargreaves–Samani. The results showed that the Hargreaves–Samani equation serves as an alternative tool to predict ETo when fewer meteorological variables are available. The calculated local growth-stage-specific Kc can help improve irrigation water management in this region. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Water scarcity is an extreme global concern due to changing climate and rapid population growth. Worldwide, freshwater sources are depleting and there is a need to implement water-conserving approaches in water-limited or arid areas for sustainable crop production. Therefore, this study aimed to investigate the impact of deficit irrigation on cucumber plant physiology, growth, and fruit yield traits grown under greenhouse conditions. The experiment was conducted in a complete randomized design with four water regimes, 100%, 80%, 60%, and 40% crop water requirement (ETc). Results showed that the highest plant leaf chlorophyll contents (43.2 µmol m-2), plant biomass (12.43 g), plant height (172.39 cm), number of leaves (19.85), fruit yield (2.49 kg), and total soluble solids (3.73 °Brix) were in plants irrigated at 100% level. In comparison, the lowest plant height (115.73 cm), number of leaves (15.77) and fruit yield (1.81 kg) were recorded at 40% irrigation. Results revealed that reduced irrigation regimes up to 80% or 60% have no significant inhibitory effects on cucumber agro-morphological traits. However, 40% of irrigation levels showed significantly reduced plant morphological and fruit yield traits. Overall, the result demonstrated that regulated deficit irrigation can significantly conserve water without negatively impacting cucumber yield.

High-density olive groves, despite their interesting production potential, have several limitations, including their high fruit load and irrigation requirements. This study aimed to evaluate the effects of fruit load and deficit irrigation on oil yield, fruit quality, and olive chemical composition in a high-density olive grove (cv Sikitita). Our main hypothesis was that primary metabolism, as influenced by crop load and stress, could modify the accumulation of different phenolic classes. Different fruit loads were generated through flower thinning (66%, 50%, 33%, 0%), and two deficit irrigation treatments (−60%, −75%) were compared to the well-watered control (920 m3/ha). Thinning treatments had a limited effect on oil yield; on the other hand, deficit irrigation caused considerably less oil accumulation in the fruit on all sampling dates. Thinning 66% and deficit irrigation 75% were considered with the control for untargeted metabolomic analysis, including three sampling dates. A total of 233 distinct phenolic compounds were annotated. Multivariate HCA results indicated that harvest time had an impact on the phenolic profile of olive fruits, obtaining two separated clusters that grouped t1 and t2 together and apart from t3, which clustered independently. Regarding agronomic techniques, they played a differential role in the phenolic profile (supervised OPLS-DA). Fruit load mostly affected flavonoid glycosides. In contrast, the phenolic response to deficit irrigation was more heterogeneous, with phenolic acids (35%), flavonoids (25%), LMW, and other phenols (25%).