Deficit Irrigation Research Articles (Page 1)

Effects of regulated deficit irrigation, boron and zinc applications on peanuts growth and seed yield in arid conditions

Abstract This study, conducted under semi-arid conditions during the 2022 and 2023 growing seasons, aimed to assess the effects of plant growth-promoting rhizobacteria (PGPR) in combination with different irrigation levels and water qualities on safflower (Carthamus tinctorius L.) quality parameters. The irrigation levels were based on 0% (I0 - rainfed), 25% (I25), 50% (I50), 75% (I75), and 100% (I100) of Class A pan evaporation. Two irrigation water qualities were used: recycled wastewater (RW) and freshwater (FW). The PGPR treatments were applied at four frequencies: R0 (control), R1 (once), R2 (twice), and R3 (three times) starting after sowing at 10-day intervals. Seed protein content ranged from 12.0% to 18.1%, with the highest values under I100-R3 and the lowest under I0-R0. Protein content increased with irrigation and bacterial application frequency. Oil content varied between 25.2% and 38.6%, peaking under full irrigation with triple PGPR application (I100-R3), and was generally higher in RW-irrigated plots. SPAD (Soil Plant Analysis Development) values which are an indication for chlorophyl content in the plant ranged from 45.1 to 76.3, with RW-I100 treatments showing the highest readings. Stomatal conductance values varied between 40.5 and 122.0 mmol/m 2 /s¹, increasing with irrigation level. Overall, combining recycled wastewater and PGPR under sufficient irrigation significantly improved safflower’s physiological and biochemical characteristics. The results suggest that this integrated approach enhances oil and protein content while supporting sustainable water use and crop quality improvement in arid and semi-arid regions.

The survival and growth of Faidherbia albida A. Chev seedlings using biochar and deficit irrigation in drylands of Tigray, Ethiopia

Spatiotemporal modeling for enhancing winter wheat yield and water productivity in dryland farming with supplemental irrigation under variable rainfall conditions

Productive and physiological response of Pereskia grandifolia Haw. irrigation deficit with grey and brackish water in the Brazilian Semiarid Region

Assessing the impact of soil water deficit and supplemental irrigation scenarios on Ohio’s maize and soybean yields using machine learning models

Deficit irrigation alleviates the increase in soil salinity content in saline-alkali regions of China and improves irrigation water productivity: A meta-analysis

Farmers agronomic management responses to extreme drought and rice yields in Bihar, India

Drought stress is a major constraint in eggplant cultivation, limiting growth, physiological performance and yield. Solanum relatives may provide alleles for improving drought tolerance. The objective of this study was to evaluate the responses of cultivated, wild and interspecific eggplant genotypes under water stress to identify drought-tolerant genotypes. Four-week-old plants of three Greek eggplant cultivars—S. macrocarpon (cultivated), S. dasyphyllum (wild), and three S. melongena × S. dasyphyllum hybrids—were grown under full and deficit irrigation and assessed for 10 agronomic and 7 physiological traits. Genotype, irrigation level and their interaction significantly affected most traits. Eggplant showed greater sensitivity under water stress with reductions in 9 agronomical traits, such as leaf number (12.9–15.8%), plant height (15.4–25.1%), LAI (47.7–55.4%), root (32.1–46.6%) and plant biomass (31.4–38.6%). S. dasyphyllum and S. macrocarpon maintained relative growth and physiological stability through different mechanisms, indicating enhanced drought tolerance. S. dasyphyllum exhibited reduction only in leaf number (11.5%), plant height (17.8) and LAI (23.9%), while S. macrocarpon exhibited reduction only in leaf length (18.1%) and LAI (55.0%). Interspecific hybrids displayed intermediate responses and heterosis under control (−22.2 to 66.6%) and stress (−29.8 to 81.5%) conditions. These findings support the use of wild or cultivated germplasm in breeding drought-resilient eggplant cultivars and rootstocks and enhancing crop sustainability.

Coastal agricultural system in Odisha faces significant challenges from soil salinity, water scarcity and climate variability. This study evaluated integrated climate-resilient agricultural practices for enhancing yield, water productivity and economic returns in rainfed saline-affected coastal rice ecosystems. A two-year study (2023 and 2024) was conducted in Achhutadaspur village of Erasama Block, Jagatsinghpur district, Odisha, under the NICRA-TDC project. The experiment compared traditional practices with various combinations of interventions including deep ploughing, green manuring with Sesbania aculeata, salt-tolerant rice variety and integrated water management with farm pond. Data on yield, water productivity, soil health parameters and economic indicators were collected and analyzed. The full integrated package with deep ploughing, green manuring, salt-tolerant rice variety and supplemental irrigation from farm pond (T₅) significantly increased rice yield from 30,500 kg/ha (T₁) to 43,500 kg/ha (42.6% increase) and net returns from Rs 24,650/ha to Rs 44,550/ha (80.7% increase). The benefit-cost ratio improved from 1.54 to 1.80. Irrigation water productivity reached 3.95 kg/m³, while total water productivity improved from 0.29 kg/m³ to 0.38 kg/m³. Economic water productivity increased by 63.6%, from Rs 2.36/m³ to Rs 3.86/m³. The farm pond infrastructure demonstrated a payback period of 3.5 years with an internal rate of return of 25.96%. Soil health parameters showed remarkable improvement, with the integrated package reducing soil EC by 25% and increasing organic carbon by 26.3% compared to traditional practice. The integration of soil health management, salt-tolerant variety and water harvesting structures significantly enhances rice-based ecosystem resilience in coastal saline environments. This approach effectively addresses dual challenges of soil salinity and water scarcity while improving farmers' livelihoods, offering a replicable model for similar coastal regions. This experiment has been conducted in the farmers’ field; it can also be studied in the research plots to have better control on the treatments.

Enhancing the utilization of water in desert areas, including Saudi Arabia, has become essential for achieving agricultural sustainability. Biochar effectively mitigates ecological stresses through retaining water, altering soil properties, and providing nutrients for plant growth. This study aimed to examine the impacts of biochar addition on morpho-physiological characteristics, yield, and water productivity (WP) in greenhouses under drought stress conditions. The experiment combined three levels of deficit irrigation (DI)—40, 60, and 80% ETc—as well as two rates of biochar (BC)—BC3% and BC5% w/w (1.28 and 2.13 kg m−2, respectively, for planted area); the control was 100% ETc and untreated soil (BC0%). The results indicated that water deficit hurt the plants’ morpho-physiological characteristics and crop yield. For instance, irrigation water shortage decreased yield by 30.88% at 40% ETc compared to the control (100% ETc). However, DI improved WP by 72.80% at 40% ETc compared to the control. The interaction between DI and BC positively affected morphological, physiological, yield, and WP. For instance, the highest rate of biochar (BC5%) increased yield by 11.92% at 80% ETc compared to untreated plants (BC0%). Similarly, tomato plants treated with 5% biochar under the lowest irrigation level of 40% ETc achieved the highest increase in WP (79.33%) compared to the control (100% ETc and BC0%). In general, DI combined with BC could improve morpho-physiological attributes and yield while increasing the WP of tomato plants in arid and semi-arid regions.

Understanding the impact of rising environmental temperatures on Vitis vinifera is crucial for the wine industry in the context of global warming. This study investigated the combined effects of elevated daytime temperatures (ET) and moderate irrigation restriction (IR) at post-veraison, over four seasons in two widely cultivated cultivars in Argentina: Malbec and Bonarda. An open-top chamber with a passive air heating system was used to increase average daytime temperatures by approximately 2 °C. In general, vegetative growth parameters were not affected by ET or IR throughout the study, indicating no cumulative effects. Bonarda yield was reduced by ET due to fewer berries per bunch, and lighter berries and clusters, but remained unaffected by IR. In contrast, Malbec maintained stable yields under both ET and IR, suggesting greater adaptability. In both cultivars, ET led to increased sugar accumulation and higher alcohol content in wines, but also reduced wine colour intensity, colour index, and co-pigmented anthocyanins, while there were cultivar-specific differences. Despite these common negative effects, Malbec showed favourable traits under ET, including improved anthocyanin stability (higher proportions of acylated forms) and increased hue. The IR treatment restored colour intensity and increased the total polyphenol index in both cultivars, and also recovered colour index in Malbec. Overall, our findings suggest that Malbec exhibits greater phenotypic plasticity and potential for high-quality wine production under moderate post-veraison water stress and elevated temperature, compared to Bonarda. This irrigation strategy may help mitigate some of the adverse effects of elevated temperature by preserving wine colour and stability without significantly compromising vine growth or yield.

It is well known that the water consumption of some tropical fruits is high. However, in the world and especially in agricultural areas, where the Mediterranean climate prevails, drought is defined as one of the most important abiotic stress factors that affect product patterns. For this reason, this research chose the pitaya (Hylocereus spp.) plant, which has relatively low water consumption among tropical fruit species. Three different training (Control [Pole], T and Inverted U) systems with different deficit irrigation (combined with FULL = 100%; DI75 = 75%, DI50 = 50% and DI25 = 25%) treatments in the cultivation of pitaya under greenhouse conditions; their effects on the yield, evapotranspiration, water use efficiency, irrigation water use efficiency, yield response factor and some quality parameters (fruit weight, length and width, fruit flesh hardness and water-soluble dry matter) were examined. The research was carried out in Antalya province, Turkey between 2018 and 2021 and ‘Vietnamese Jaina’ was used as a cultivar. Irrigation applications were carried out using drip irrigation method and the amount of irrigation water to be used in the control (FULL) treatment was calculated based on measurement values taken from the A-Class evaporation pan. The research findings revealed that the amount of irrigation water varied between 27.63 mm and 83.80 mm, and the fruit flesh value ranged between 79.36 kg cm−2 and 105.53 kg cm−2. In general, as the irrigation water level decreases, a decrease in fruit flesh values is also recorded. In addition, it was found that different irrigation water levels affect yield. The average yield values were found as DI75 (7169.60 kg ha−1) > FULL (5783.90 kg ha−1) > DI50 (4737.00 kg ha−1) > DI25 (4376.30 kg ha−1) ranking from high to low. Yield varied according to the training system, with the highest value recorded in the Pole (Control) System (5625.30 kg ha−1) followed by Inverted U System (5594.90 kg ha−1) and T System (5330.00 kg ha−1). As an important finding for yield values, it was found that the treatment DI75 irrigation has a general superiority over the other irrigation treatments. Based on the research findings, considering the yield and quality parameters, a Pole (Control) System and an Inverted U System were recommended as a training system, respectively, along with the irrigation treatment (DI75), in which 75% of the water needed by the plant is given in greenhouse conditions considering the evaporation.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12870-025-07442-5.

Abstract The appropriate growth medium configuration is a crucial agronomic practice for water utilization, especially in arid areas. This issue is of particular importance in calcareous soils, where crop plants suffer from limited water and nutrient availability. Therefore, the present investigation aimed to estimate the yield performance and irrigation water use efficiency of sesame grown in different sowing patterns under different irrigation levels. A-2 year field trial was carried out in two summer seasons (2022 and 2023) in a strip-plot with a randomized complete block design using three replications. Three sowing patterns (flat, ridges, and beds) were allocated vertically. Irrigation water levels (100, 75 and 55% of evapotranspiration, ETc 1 , ETc 2 and ETc 3 , respectively were applied and distributed horizontally. ETc 1 × beds followed by ETc 2 × ridges or beds in both seasons were the efficient combinations for producing the highest increases in capsules number plant −1 . ETc 1 × beds or ETc 2 × ridges recorded the shortest height of the first capsule in both seasons. The maximum seed yield was achieved with ETc 2 × beds in both seasons (1262.3 and 1313.3 kg ha −1 ), respectively, and ETc 2 × ridges in the first season (1222.9 kg ha −1 ). ETc 3 × beds (for oil % and oil yield ha −1 in both seasons) and ETc 2 × beds (for oil yield ha −1 in the first season) exhibited the highest increases. ETc 3 × beds interaction gave the maximum increase in irrigation water use efficiency in both seasons. The phenotypic correlation and path-coefficient analysis illustrated that the direct effects of seed index and capsules number plant −1 on seed yield plant −1 showed highly positive values (4.89 and 2.84 in 2022) and (1.01 and 1.01 in 2023). By adopting the beds method for cultivating sesame in arid zones, the irrigation programs should be modified via applying the deficit irrigation strategy to save water (about 25%) while keeping productivity. The findings provide new insights into optimizing resource use through beds sowing and moderate irrigation, contributing to sustainable sesame production in water-limited environments. Further, in order to develop stress-tolerant sesame varieties, breeders should focus primarily in breeding programs on improving capsules number plant −1 and seed index traits due to their great direct contribution influence on seed yield, as indicated by path-coefficient analysis.

BackgroundDrought stress is a major constraint to the growth and productivity of Phaseolus vulgaris, particularly in dry regions. Utilizing natural biostimulants offers an eco-friendly approach to enhancing drought tolerance by modulating plant physio-biochemical responses. This study investigates the effectiveness of diluted lemon fruit juice (DLFJ) and diluted bee honey (DBH) as foliar biostimulants to mitigate drought-induced stress in P. vulgaris under two irrigation regimes: full (100% ETc) and deficit irrigation (60% ETc).ResultsBoth DLFJ and DBH treatments significantly enhanced photosynthetic efficiency, relative water content (RWC), membrane stability index (MSI), osmoprotectant levels, antioxidant activity, and nutrient accumulation under drought conditions. Among all treatments (4% and 8% DBH, and 3% and 6% DLFJ), DBH-4% was the most effective. It significantly increased chlorophyll and carotenoid contents, photosynthetic efficiency, leaf integrity (RWC and MSI), osmoprotectant levels, antioxidant activities, and green pod yield under 60% ETc compared to untreated controls. It also markedly reduced oxidative stress markers (e.g., malondialdehyde and hydrogen peroxide) and further boosted enzyme activities, including superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase.ConclusionsThese findings demonstrate that DBH-4% is a promising and sustainable biostimulant for improving drought resilience in P. vulgaris. Its rich content of antioxidants and osmoprotectants confers significant physiological and agronomic gains under water-limited conditions.

Abstract Although the immediate benefits of biochar in enhancing nitrogen cycling and crop productivity are well documented, its residual effects across different biochar types and irrigation regimes over successive growing seasons have not been fully elucidated. Here, we assessed the residual effects of softwood (SWB) and wheat-straw (WSB) biochar on soil–plant nitrogen (N) dynamics and maize ( Zea mays L.) productivity over two growing seasons following a one-time application. Experiments were conducted in 2021 and 2022 under full (FI), deficit (DI), and alternate partial root-zone drying (APRI) irrigation. In both years, despite limited changes in water consumption and total N uptake, WSB-APRI combination improved total dry biomass (+ 13.5%), harvest index (+ 4.4%), water use efficiency (+ 26.7%), and N use efficiency (+ 10.3%). These improvements were linked to enhanced microbial activity (+ 26.8–51.2%) and soil N availability (+ 4.8–13.2%), which stimulated root growth (+ 7.4–22.7%) and N uptake (+ 7.0–17.8%) under water stress. However, under reduced irrigation in 2021, SWB markedly suppressed microbial respiration (− 42.4%) and N availability (− 29.2%), which in turn led to compromised crop performance, particularly under DI. Partial least squares path modeling revealed that microbial activity and root traits indirectly affected maize water and N use efficiency by influencing water consumption, N uptake, and biomass accumulation. Notably, excessive N uptake reduced N use efficiency, whereas biomass accumulation enhanced it. Considering the residual effects of biochar, APRI combined with WSB offers a promising approach to continuously enhance water-nitrogen coordination and maintain maize productivity under limited irrigation. Graphical Abstract

Cassava productivity in rainfed tropical regions is declining due to prolonged dry seasons and increasingly unpredictable rainfall patterns. In this study, we address these challenges by evaluating the application of a semi-automatic drip irrigation system combined with earlier planting times in the dry season. The goal is to increase yields and water use efficiency (WUE) in Gajah cassava varieties. In this field research, two treatments were compared: (P1) planting at the beginning of the dry season with drip irrigation support during the vegetative phase, and (P2) planting at the beginning of the rainy season conventionally without irrigation. Results showed that P1 significantly outperformed P2, achieving a 42.4% higher yield (110.95 tons/ha vs. 77.94 tons/ha) and a 34% improvement in WUE (4.896 kg/m³ vs. 3.654 kg/m³). In treatment P1, supplemental irrigation only covered 2.84% of the total water input, indicating its efficiency in mitigating early drought stress and supporting initial crop growth. Statistical analysis showed a significant difference in yield (p < 0.05), with P1 showing a higher response despite greater variability. These findings support the implementation of precision agriculture strategies that integrate planting schedules with seasonal rainfall patterns and targeted irrigation use. The semi-automated system, powered by solar panels and grid electricity, provides a scalable, cost-effective solution, particularly suitable for small-scale farmers in semi-arid and hilly areas. Future research should assess the long-term effects across agroecological zones. Additionally, irrigation protocols need refinement for different cassava growth stages. This integrated approach contributes to climate-smart agriculture by improving resource efficiency, crop resilience, and sustainability in water-limited environments. Keywords: Climate-smart agriculture, water productivity, precision irrigation, rainfed cropping systems, smallholder innovation.

Originating from the practical demands of digital irrigation district construction, this study aims to provide support for precise irrigation management. This study developed a reinforcement learning-based intelligent irrigation decision-making model for districts employing traditional surface flood irrigation methods. Grounded in the theoretical framework of water cycle processes within the Soil–Crop–Atmosphere Continuum (SPAC) system and incorporating district-specific irrigation management experience, the model achieves intelligent and precise irrigation decision-making through agent–environment interactive learning. Simulation results show that in the selected typical area of the irrigation district, during the 10-year validation period from 2014 to 2023, the model triggered a total of 22 irrigation events with an average annual irrigation volume of 251 mm. Among these, the model triggered irrigation 18 times during the winter wheat growing season and 4 times during the corn growing season. The intelligent irrigation decision-making model effectively captures the coupling relationship between crop water requirements during critical periods and the temporal distribution of precipitation, and achieves preset objectives through adaptive decisions such as peak-shifting preemptive irrigation in spring, limited irrigation under low-temperature conditions, no irrigation during non-irrigation periods, delayed irrigation during the rainy season, and timely irrigation during crop planting periods. These outcomes validate the model’s scientific rigor and operational adaptability, providing both a scientific water management tool for irrigation districts and a new technical pathway for the intelligent development of irrigation decision-making systems.

This study was conducted to address the critical challenges of water scarcity and inefficient input use in tomato production. The specific objectives were: 1) to evaluate the water productivity of tomato under different combinations of irrigation levels and fertilizer rates, 2) to quantify the amount of irrigation water saved using these combinations, and 3) to recommend the best water and fertilizer-saving technique for the study site. A factorial experiment was arranged in a Randomized Complete Block Design with three replications. The treatments included three irrigation levels (50%, 75%, and 100% of crop evapotranspiration - ETc) and three fertilizer (NPS) rates (50%, 75%, and 100% of the recommended amount). The results showed that the combination of 75% ETc and 75% fertilizer rate (150 kg NPS ha<sup>-1</sup>) achieved the highest water productivity (8.39 kg ha<sup>-1</sup> mm<sup>-1</sup>) and a high yield of 23,901 kg ha<sup>-1</sup>, which was statistically on par with the full irrigation and fertilizer treatment. This optimal treatment resulted in water savings of 25% (94.95 mm) compared to the full irrigation regime. It is concluded that applying 75% of both the recommended irrigation water (ETc) and fertilizer rate is the best technique for the study site, enabling significant resource conservation without compromising yield. This strategy is recommended for extension to farmers to enhance sustainable productivity.

Saffron (Crocus sativus L.) is one of the most valuable medicinal plants, but its production is highly constrained by drought stress and excessive dependence on chemical fertilizers, which adversely affect both yield and quality while raising environmental concerns. The aim of this study was to evaluate the impact of endophytic fungi (Penicillium chrysogenum and Serendipita indica) and silicon concentrations under different irrigation regimes on growth, yield and nutritional quality of saffron (Crocus sativus L.) with an intention to reduce reliance on chemical fertilizers utilizing sustainable agricultural practices. This experiment was conducted as a factorial experiment in a completely randomized block design with 27 treatment combinations of Penicillium chrysogenum, Serendipita indica, silicon, and different irrigation levels with three replications during the 2022–2023. Application of Penicillium chrysogenum, and Serendipita indica fungi, solely or in combination with silicon significantly enhanced the stigma fresh weight, stigma dry weight, saffron yield, stigma length, daughter corm number, daughter corm weight, leaf length and number, leaf dry weight, root length, root fresh and dry weight, picrocrocin and safranal. The treatment of Serendipita indica + 200 ppm silicon was the most effectiveness, so application of Serendipita indica + 200 ppm silicon caused increases by 419.1, 29.2, 279.4, 286.5, 284.5, 55.4, 371.2, 316.9, 120.8, 163.9, 312.4, 177.6, 116.5, 116.5, 40.0, and 157.8%, respectively in the values of stigma fresh weight, stigma dry weight, saffron yield, stigma length, daughter corm number, daughter corm weight, leaf length, leaf number per plant, leaf dry weight, root length, root fresh weight, root dry weigh, picrocrocin and safranal. We recommend the application of Serendipita indica + 200 ppm silicon in order to enhancement growth and flowering, saffron yield, and saffron nutritional quality in non-stress and drought stress condition. In conclusion, this study provides a promising strategy for sustainable saffron production, and future research should validate these findings under diverse agro-climatic conditions and explore their long-term economic feasibility.