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In the context of global warming, rising air temperatures are increasing evapotranspiration ( ET c ) in all agricultural crops, including rice, a staple food worldwide. Simultaneously, the occurrence of droughts is reducing water availability, affecting traditional irrigation methods for rice cultivation (flood irrigation). The objective of this study was to determine ET c (water use) and yield performance in rice crop under different irrigation regimes: treatments with continuous flood irrigation (CF) and irrigations with alternating wetting and drying ( A W D 5 , A W D 10 , and A W D 20 ) in an experimental area in INIA–Vista Florida. Water balance, rice physiological data, and yield were measured in the field, and local weather data and thermal and multispectral images were collected with a meteorological station and a UAV (a total of 13 flights). ET c values obtained by applying the METRICTM (Mapping Evapotranspiration at High Resolution using Internalized Calibration) energy balance model ranged from 2.4 to 8.9 mm d−1 for the AWD and CF irrigation regimes. In addition, ET c was estimated by a water balance using the AquaCrop model, previously parameterized with RGB image data and field weather data, soil, irrigation water, and crops, obtaining values between 4.3 and 7.1 mm d−1 for the AWD and CF irrigation regimes. The results indicated that AWD irrigation allows for water savings of 27 to 28%, although it entails a yield reduction of from 2 to 15%, which translates into an increase in water use efficiency (WUE) of from 18 to 36%, allowing for optimizing water use and improving irrigation management. [ABSTRACT FROM AUTHOR]

Super high-density (SHD) planting systems are very efficient in terms of production and water use. In these orchards, water-saving irrigation strategies are used precisely to keep the best sustainability compared to traditional orchards. With agro-climatic and eco-physiological parameter monitoring, the SHD planting system has become even more efficient. SHD orchards, however, could also be more so affected by other pests and diseases than traditional systems, but field responses are still unknown when olive trees are grown in SHD groves. The goal of this two-year field research was to investigate the seasonal changes of the phytosanitary status of 'Arbosana' grown in an SHD orchard under both regulated deficit (RDI) and full irrigation regimes (FI). This study investigated the influence of the two different irrigation regimes on the infections of three olive tree key diseases: cercosporiosis (Pseudocercospora cladosporioides), cycloconium (Fusicladium oleagineum), and olive knot (Pseudomonas savastanoi pv. savastanoi). RDI significantly reduced the severity of cercosporiosis in 2020 compared to FI but not in 2021. Cycloconium was observed only as a latent infection during the two studied years and olive knot was not influenced by irrigation but only by weather conditions. These findings suggest that irrigation management can play a key role in controlling cercosporiosis effectively in SHD olive orchards, but also that weather conditions have an even higher impact on the tree key diseases. [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]

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]

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]

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]

Improving drought resistance in Zoysiagrass (Zoysia spp.) is a target for both private and public breeding programs. The performance of 26 elite experimental zoysiagrasses was compared under progressive drought stress with Palisades, Diamond, and Zeon. Environmental conditions were warmer and drier in 2020 (66 days) than 2021 (45 days). Irrigation was applied once weekly using potential evapotranspiration (ETo) rates and crop coefficients (Kc) of 0.6 (non‐stress), or 0.40, 0.30, and 0.25 deficit treatments. Turfgrass quality, leaf wilt, normalized difference vegetative index, normalized difference red edge, and volumetric water content were recorded weekly. Genotypes with the highest means (statistical “a” group) contributed to a turfgrass performance index (TPI). Elite zoysiagrass with TPI ≥ Palisades (19) were Zoysia japonica Steud. ecotypes DALZ 1311 (22), 1601 (19), and 1603 (21), and finer textured interspecific hybrids, DALZ 1701 (18), 1713 (26), 1714 (18), and 1801 (24). Relative to an irrigation schedule using a 0.6 Kc, these genotypes survived extreme deficit irrigation, which conserved 40.1% (45,859.6 L) and 66.4% (44, 592.2 L) of water in 2020 and 2021, respectively. Overall, this study demonstrated that significant water consumption could be reduced with proper cultivar selection and deficit‐based irrigation management while maintaining an acceptable turfgrass quality under drought conditions. [ABSTRACT FROM AUTHOR]

Agricultural drainage water production in southwestern Iran is a serious problem, but this low-quality water can be considered a potential alternative source of freshwater. In this regard, the cultivation of salinity-resistant plants using drainage water can be considered a suitable measure. Quinoa (Chenopodium quinoa Willd.) is a valuable halophyte, and the World Health Organization has recognized it as a plant that can guarantee the world's future food security. For this purpose, this study was conducted to investigate the sustainable use of drainage water for quinoa cultivation (2019–2020). First, quinoa seed germination experiments were conducted in the laboratory using four different salinity solutions [0 (control), 9, 18, and 27 dS/m ]. Then, field research was conducted in the form of a split-plot factorial design so that irrigation management and planting date were implemented as the main treatments and genotype factor as subtreatment in small plots. Four genotypes of quinoa were planted on the research farm on three dates, January 20 (D1), February 5 (D2), and February 20 (D3). Irrigation managements include irrigation with water from the Karun River (as freshwater, I1), drainage water from sugarcane fields (I2), and alternating irrigation with freshwater and drainage water (I3). An average reduction of 4% in the total germination at 27 dS/m salinity compared to the control treatment indicated that quinoa was well adapted to salinity during germination. The highest biomass was produced by the Rosada genotype cultivated on the D3 under I1 management at a rate of 540 g/m2 , followed by the Q26 genotype cultivated on the D1 under I3 management (499 g/m2). Finally, it can be concluded that, to maintain the salt balance in the soil, leaching at the end of the growing season is necessary to remove salts and maintain sustainable haloculture. [ABSTRACT FROM AUTHOR]

The water footprint is an increasingly demanded environmental sustainability indicator for certifications and labels in agricultural production. Processing tomatoes are highly water-intensive, and existing studies on water footprint have uncertainties and do not consider the impact of different irrigation configurations (e.g., surface drip irrigation (SDI) and subsurface drip irrigation (SSDI)) and irrigation strategies. This study presents a two-year experimental investigation to determine the water footprint of processing tomatoes grown in southern Spain (Andalusia) and the impact of SSDI and deficit irrigation. Five irrigation treatments were established: SDI1 (surface drip irrigation without water limitation), SDI2 (surface drip irrigation without water limitation adjusted by soil moisture readings), SSDI1 (subsurface drip irrigation without water limitation and a dripline depth of 15 cm), SSDI2 (similar to SSDI1 but with mild/moderate water deficit during the fruit ripening stage), and SSDI3 (subsurface drip irrigation without water limitation and a dripline depth of 35 cm (first year) and 25 cm (second year)). Measurements included crop vegetative growth, leaf water potential, leaf gas exchange, nitrate concentration in soil solution, and crop yield and quality. The soil water balance components (actual evaporation, actual transpiration, deep drainage), necessary for determining the total crop water footprint, were simulated on a daily scale using Hydrus 2D software. Results indicated that SSDI makes more efficient use of irrigation water than SDI. The water footprint of SSDI1 was 20–35% lower than that of SDI1. SSDI2 showed similar water footprint values to SDI1 under highly demanding environmental conditions and significantly lower values (≈40%) in a year with lower evaporative demand. The dripline depth in SSDI was critical to the water footprint. With a 35 cm installation depth, SSDI3 had a significantly higher water footprint than the other treatments, while the values were similar to SSDI1 when the depth was reduced to 25 cm. [ABSTRACT FROM AUTHOR]

The efficient use of phosphate fertilizers and optimization of the amounts of irrigation water can maximize tomato growth and fruit production. This study aimed to evaluate the effects of different phosphorus (P) doses and sources on the growth and production components of tomato plants of the cultivar Gaúcho Melhorado Nova Seleção subjected to different irrigation water percentages. To achieve this, we set up an experiment using a factorial design to test the effects of four doses of P2O5 (corresponding to 25%, 50%, 100%, and 200% of the recommended dose), two P sources (monoammonium phosphate—MAP and organomineral—OM), and four irrigation water percentages (50%, 75%, 100%, and 125% of field capacity). Tomato plant growth improved when water was supplied at a percentage close to 100% of field capacity, with increased plant height, leaf length, and number of flowers observed (increases of 11.95%, 7.33%, and 13.87%, respectively, compared to 50% of field capacity). However, both excess and deficit irrigation resulted in morphological changes in tomato plants. Additionally, we observed that OM was more effective than MAP in increasing plant diameter and number of flowers, with increases of up to 36.4% and 227.6%, respectively, when using OM. Conversely, tomato growth was negatively affected by higher doses of MAP doses, suggesting that 25% of the recommended dose may yield the best growth rates. We verified that tomato plants can compensate for low phosphorus doses by increasing productivity with higher water amounts (125%–42.40 t ha−1), but high phosphorus doses result in greater fruit production with lower water percentages (50%–41.52 t ha−1). [ABSTRACT FROM AUTHOR]

The continuous and reliable assessment of crop water status through water indicators enables the sustainable management of water resources, especially in arid or semi-arid climate scenarios exacerbated by climate change. Therefore, the main objective of this study is to determine and compare the sensitivity of indices derived from trunk diameter fluctuations for the accurate and automatic detection of changes in the water status of cherry trees. The water stress indicators examined are maximum daily trunk shrinkage (MDS), trunk growth rate (TGR), early daily trunk shrinkage (EDS), and late daily trunk shrinkage (LDS). During two growing seasons, 'Lapins' sweet cherry trees were subjected to different water stress levels: (i) a control treatment irrigated at 115% of crop evapotranspiration demand to ensure non-limiting water conditions, and (ii) a deficit irrigation treatment, with two irrigation withholding cycles. Vegetative growth was affected by water stress. Trunk daily growth rate and late daily trunk shrinkage exhibited a high variability and did not clearly show differences in plant water status. Both EDS and MDS showed a third-degree polynomial relationship with Ψstem. MDS had a lineal relationship with Ψstem of up to −1.4 MPa; however, further decreases in Ψstem did not necessarily lead to increased MDS. In contrast, EDS became non-linear at −1.8 MPa, making it a more useful plant water indicator than MDS for 'Lapins' sweet cherry trees when detecting severe water stress conditions. The frequencies of both MDS and EDS decreased from 85% to 35% when water stress increased. Therefore, the information provided by MDS and EDS frequencies, along with their daily values, could be useful as irrigation management tools for sweet cherry trees. [ABSTRACT FROM AUTHOR]

Due to their intensive cultivation, horticultural crops are particularly susceptible and vulnerable to the detrimental effects of drought stress, necessitating significant water inputs for optimal growth and yield. Accordingly, water-saving irrigation strategies, i.e., Partial Root zone Drying (PRD) and Regulated Deficit Irrigation (RDI) emerge as pivotal tools for bolstering the resilience of the horticultural sector. The current study aims to evaluate the impact of PRD and RDI strategies on pepper (Capsicum annuum L.) growth, and physio-biochemical attributes under semi-controlled greenhouse conditions. Research findings revealed pronounced enhancements in stem length under both irrigation strategies, with PRD exhibiting superior effects on shoot fresh and dry biomass (increases of 57.2% and 61.1%, respectively) compared to full irrigation. At the physiological level, PRD and RDI induced a significant reduction in stomatal conductance in pepper plants relative to full irrigation, while maintaining leaf water potential and relative water content. Biochemically, plants subjected to PRD and RDI methods exhibited significant accumulation of free proline, particularly pronounced with PRD (approximately 115.9% increase compared to full irrigation). Furthermore, Chl a and carotenoid concentration significantly increased under PRD, indicating sustained photosynthetic functionality. Comparatively, PRD appears as the more effective technique, offering the potential to conserve agricultural water about 50 without compromising growth parameters, while simultaneously enhancing tolerance traits in C. annuum. Nonetheless, further investigations on other traits across diverse soil types, climates, and cultivars under field conditions are imperative to ascertain the broader applicability of PRD and optimize its implementation. [ABSTRACT FROM AUTHOR]

Climate change significantly impacts agriculture and forage production, requiring the implementation of strategies toward increased water and energy use efficiency. So, this study investigated the yield of forage cactus (Opuntia stricta (Haw.) Haw) under different irrigation depths using brackish groundwater (1.7 dS m−1), whose management was based on reference evapotranspiration (ETo) estimated by the Hargreave–Samani (HS) and Penman–Monteith (PM) equations. The research was conducted in Independência, Ceará, Brazil, under the tropical semi-arid climate. A randomized block design in a 2 × 5 factorial scheme was employed, varying the ET0 estimation equations (HS and PM) and irrigation levels (0; 20; 40; 70; and 100% of total required irrigation—TRI). Growth, productivity, and water use efficiency variables were evaluated at 6, 12, and 18 months after treatment initiation. The economic analysis focused on added value, farmer income, and social reproduction level. The results showed no isolated effect of the equations or their interaction with irrigation depths on the analyzed variables, suggesting that irrigation management can be effectively performed using the simpler HS equation. Furthermore, there was no statistical difference between the means of 100% and 70% TRI as well as between 70% and 40% TRI for most variables. This indicates satisfactory crop yield under deficit irrigation. Dry matter productivity and farmer income at 12 months resulting from complementary irrigation with depths between 40% and 70% of TRI were significantly higher than under rainfed conditions. The 70% depth resulted in yields equivalent to those at 100% TRI, with the social reproduction level being achieved on 0.65 hectares in the second year. [ABSTRACT FROM AUTHOR]

In light of the current water scarcity, one strategy for reducing water consumption in irrigated agriculture is to reduce the amount of irrigation water compared to full crop irrigation or in other words deficit irrigation. Deficit irrigation management may be a critical issue due to climate change. Incorporation of different soil conditioners can improve soil hydro-physical properties and mitigate negative effects in water-stressed conditions. Recent review articles either addressed specific crop behavior under water deficit or covered a single type of soil conditioners. This manuscript represents an inclusive review providing insight into deficit irrigation methods incorporated with different soil conditioners. Crop response to deficit irrigation is discussed in the light of some mathematical models. Three main types of soil conditioners are covered: bentonite, biochar, and super-absorbent polymers. Mechanisms associated with effects of each conditioner to enhance soil water retention is highlighted as well. Previous study findings were discussed comparatively and future prospective, recommendations and challenges were addressed. [ABSTRACT FROM AUTHOR]

Introduction: The increasing pressure on land and water resources, fueled by high population growth and climate change, has profound implications for crop yield and quality. While studies thrive for various crops, a notable research gap exists in understanding the responses of forage crops to irrigation and nutrient management in developing countries. This study aims to address this gap by assessing the impact of irrigation and fertilizer application on forage production in the Ethiopian sub-humid highlands. Methods: The experiment focused on four forage varieties, namely Napier grass (Cenchrus purpureus) cultivars, ILRI-16791, ILRI-16819, ILRI-16803, and Guinea grass (Megathyrsus maximus) ILRI-144 cultivated in experimental plots. Three irrigation levels designated as IR60 (60% of total available soil water), IR80 (80%), and IR100 (100%) were applied, along with three fertilizer rates: organic manure at 30 t ha-1, and Urea-N at 100kgha-1 and 300kgha-1. Agronomic data including growth performance, forage dry matter yield, and nutritional quality were collected during two trial years. Results and discussion: Among the various irrigation treatments, IR80 demonstrated the most favorable balance between forage yield, WUE, net benefit, and LWP. In addition, the highest DMY, WUE, net benefit, and LWP were obtained for UREA at the rate of 300kgha-1 while the lowest DMY and WUE were observed for UREA at the rate of 100kgha-1. Significant variations were observed among the four forage varieties, with Napier grass ILRI-16791 having the highest DMY (9.8 tons ha-1), WUE (39kgha-1 mm-1), LWP (0.28 USD m-3 for local cows, and 1.04 USD m-1 for crossbred cows), and net benefit (783 USD ha-1). For all forages combined, a 40 and 20% decrease in irrigation increased water use efficiency by 17 and 9.4%, respectively. These results indicate that a moderate level of deficient irrigation such as IR80 could be a viable water management strategy for irrigated forage, especially in water-scarce areas. The conserved water saved from the deficit irrigation can thus be used to irrigate additional land, contributing to a more sustainable and efficient water usage approach. [ABSTRACT FROM AUTHOR]

The availability of water is a major concern in regions with limited water resources. In such regions, the focus of irrigation management shifted from producing per unit area to producing per unit of water consumed, water productivity. An experiment was carried out, for two consecutive years(2020 and 2021) at the research farm of Shire-Maitsebri Agricultural Research Center, Tselemty district, Tigray, Ethiopia to exmine the response of tomato to deficit irrigation at various growth stages. A randomized complete block design with three replications was used. Combination of three irrigation regimes (100%, 50%, and 25% of full irrigation requirement) and four FAO-defined tomato growth stages (initial, developmental, mid, and late seasons) were considered to form a total of nine treatments. Data on agronomy and irrigation water were collected and analyzed statistically. The results revealed that reducing irrigation amount up to 75% during the development growth stage significantly decreased marketable yield by 66.5%. However, the highest water use efficiency (9.2 kg/m3) was achieved by reducing irrigation amount by 75% during the end-growth stage of tomatoes. Treatments with the lowest water use efficiency (3.5 kg/m3) were those receiving 75% less irrigation amount than the full requirement during the development growth stage. Reducing irrigation to less than 75% of the full requirement during tomato development stages can greatly impact marketable yield and water use efficiency. Therefore, the tomato crop is highly susceptible to water stress when receiving more than 50% of the full irrigation requirement during its developmental growth stage. [ABSTRACT FROM AUTHOR]

Canopy temperature provides valuable information for efficient irrigation management and for detecting drought injury in a fast and non-destructive way. It also helps quantify the trade-offs between water conservation and the cooling benefit of the irrigated urban landscape, a critical issue in semiarid inland southern California with limited available water resources. Two adjacent hybrid bermudagrass and tall fescue irrigation trials were conducted to determine canopy temperature changes under a wide range of irrigation treatments from 2017 to 2019 in Riverside, California, USA. The canopy temperature data were also used to develop an empirical crop water stress index (CWSI) for each species. The CWSI values ranged from -0.15 to 0.71 for tall fescue and from -0.28 to 0.54 for hybrid bermudagrass. We observed a moderate correlation between visual rating scores (VR) and CWSI values for tall fescue (r = -0.68) and hybrid bermudagrass (r = -0.61). The fitted linear regression between VR and CWSI data suggested CWSI thresholds close to zero for both species to maintain their acceptable visual quality. The irrigation level consistently showed a significant effect on canopy temperature for both species. On average, a 10% decrease in irrigation application increased the canopy temperature of tall fescue and hybrid bermudagrass by 1.3°C and 0.9°C, respectively. Therefore, deficit irrigation might reduce the cooling benefits of irrigated urban lawns in the semiarid climate of inland southern California. [ABSTRACT FROM AUTHOR]

Mulching is a widely adopted agronomic practice, often used as a water-saving strategy due to its effectiveness in reducing soil evaporation. However, effects vary depending on the materials used and the extent of mulch soil coverage. Consequently, the impacts of mulching may differ considerably across production systems, preventing the establishment of reliable guidelines for irrigation water management. The objective of this study is to comprehensively review existing literature that compares mulching versus no-mulching management, aiming to gain a deeper understanding of the effects of mulching on soil evaporation (Es), crop coefficients (Kc), and actual crop evapotranspiration (ETc act). 58 studies were selected. The impact of mulching was particularly notable in the early crop stages, when the soil is not fully covered. Data in literature shows that plastic films were more effective in reducing Kc than organic materials. However, this effect, while evident during the early crop stages, diminished throughout the rest of the season. Black plastic films were more effective during the early crop stages compared to other colored plastics, particularly relative to the decrease of Kc, but this effect also diminishes during the rest of the season. Building upon these findings, the study provides guidelines for expected reductions in Kc values based on the type of crop, crop stage, and the mulching material most used in each cropping system. [ABSTRACT FROM AUTHOR]

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

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

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

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

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

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

ABSTRACT Brazil is the world’s largest soybean exporter. Over half of the cultivated area is in the Brazilian Savanna (Cerrado) region, where soybean is typically grown under rainfed conditions. However, soybeans have been cultivated in irrigated systems, further increasing water demand in the region, which already faces water problems. Therefore, it is crucial to generate technical information to support the management of water resources in irrigated soybean crops. This study aimed to estimate the water deficit sensitivity index of soybean crops. Two field experiments were carried out in randomized blocks with four treatments and four replicates from May to Aug 2019 and 2021. Three treatments with irrigation suspension were applied in three different phenological stages: vegetative, reproductive, and seed filling, and a fully irrigated control plot to meet the total plant demand. The results showed 40 % and 34 % reductions in soybean seed yield when water deficit was applied in stages R1-R5 and R5-R7, respectively, compared to the control treatment. There was a linear correlation with r2 values equal to 0.98, 0.97, and 0.99 for the relationships between seed yield and applied irrigation, seed yield and actual evapotranspiration (ETa), and ETa and irrigation, respectively. The yield response factors were equal to 0.12, 0.36, and 0.57 for the stages V2-R1, R1-R5, and R5-R7, respectively. The yield response factor for the soybean cycle was equal to 1.16.

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell 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.)

Knowing the effect of water deficit intensity on the nutrient uptake dynamics by common bean cultivars with contrasting growth habits in different years is necessary to appraise and recommend more specific fertilization management practices. A field study was carried out in the Southeast of Brazil for two years aiming to explain and compare the accumulation and extraction of the macronutrients nitrogen (N), phosphorus (P), and potassium (K) from two common bean cultivars with contrasting growth habits as a function of water deficit severity. The common bean cultivars IAC Imperador and IPR Campos Gerais, with determinate and indeterminate growth habits, respectively, were evaluated. Both cultivars were submitted to three irrigation management practices: severe water deficit (54% of the crop evapotranspiration -- ETc), moderate water deficit (77% of ETc), and no water deficit (100% of ETc). Overall, the severe water deficit reduced N, P, and K accumulation in the common bean cultivars by 26, 37, and 23%, respectively. Under no water deficit, IPR Campos Gerais showed higher accumulation of biomass and nutrients N (27%) and P (42%) compared to IAC Imperador, in addition to higher interannual variability in the accumulation of nutrients. The maximum daily demand for nutrients N, P, and K of IAC Imperador was anticipated in 9, 13 and 11 days, respectively, compared to IPR Campos Gerais. Irrigation management, cultivar, and climate of the agricultural year are important factors in decision-making for the most adequate establishment of fertilization with N, P, and K in common bean. [ABSTRACT FROM AUTHOR]

Climate variability in Mediterranean viticultural areas, primarily attributed to climate change, will significantly impact water requirements, consequently leading to changes in irrigation management. The primary aim of this study was to assess the response of the Tempranillo and Cabernet Sauvignon grape varieties when subjected to deficit drip irrigation (RDI), in comparison to non-irrigation (NI), during various climatic years. The defined irrigation strategies involved water application equivalent to 35% and 80% of the (ET0 (reference crop evapotranspiration) × Kc (crop coefficient)). The ecophysiology of both grapevines was evaluated through the measurement of stomatal conductance (gs), sap flow, transpiration, leaf water potential (LWP), and CO2 assimilation (A). Additionally, essential parameters including the crop coefficient (Kc), transpiration, and intrinsic water use efficiency were calculated. The information gathered from the pressure–volume curves of Cabernet Sauvignon and Tempranillo encompassed the osmotic potential at full turgor (γπ100), osmotic potential at turgor loss or 0 turgor (γπ0), water content at turgor loss (CHR0), modulus of elasticity (ε), and water potential at turgor loss 0 (γH0). The results enable a precise estimation of the water requirements for irrigation, contributing to a deeper understanding of the physiological responses of both varieties. This comprehension aids in assessing the sustainability of these vineyards amidst unexpected changes in the global mean surface temperature. [ABSTRACT FROM AUTHOR]

Saudi Arabia faces water scarcity and inadequate sustainable sources, particularly in agriculture, necessitating efficient irrigation water management to improve productivity amidst rising demand. The study investigated the impact of irrigation levels and water salinity on tomato plants in greenhouses, covering four irrigation levels (100%, 80%, 60%, and 40% of ETc) and three water sources (FW (0.9 dS·m−1), SW (3.6 dS·m−1) and MW (2.25 dS·m−1)). Salinity impacts crop yield, physiological responses, and fruit quality. The photosynthesis, stomatal conductance, transpiration, and chlorophyll content decrease with MW and SW, negatively affecting morphological characteristics. For MW, it was recommended to apply 60% deficit irrigation with a yield of 98 kg·ha−1, and water productivity (WP) improved to 21.93 kg·m−3 compared to 13.65 kg·m−3 at full irrigation (FI). In SW, 80% irrigation was suggested, as there was no significant difference in yield compared to FI. For FW, 60% deficit irrigation produced the best water conservation (104.58 kg·ha−1 yield and 23.19 kg·m−3 WP), while FI produced the highest yield per unit area (123.48 kg·ha−1 yield and 16.51 kg·m−3 WP). Nonetheless, greater water and salinity stress was associated with increased fruit quality measures such as total acidity, vitamin C, and soluble solids. The results show that implementing deficit irrigation with salinity strategies in greenhouse tomatoes could improve crop adaptability, yield, and water productivity in the face of water scarcity and salinity variability. [ABSTRACT FROM AUTHOR]

Alternate wetting and drying irrigation (AWD) has been shown to decrease water use and trace gas emissions from paddy fields. Whereas genotypic water use shows little variation, it has been shown that rice varieties differ in the magnitude of their methane emissions. Management and variety‐related emission factors have been proposed for modelling the impact of paddy production on climate change; however, the magnitude of a potential reduction in greenhouse gas emissions by changing varieties has not yet been fully assessed. AWD has been shown to affect genotypic yields and high‐yielding varieties suffer the greatest loss when grown under AWD. The highest yielding varieties may not have the highest methane emissions; thus, a potential yield loss could be compensated by a larger reduction in methane emissions. However, AWD can only be implemented under full control of irrigation water, leaving the rainy seasons with little scope to reduce methane emissions from paddy fields. Employing low‐emitting varieties during the rainy season may be an option to reduce methane emissions but may compromise farmers' income if such varieties perform less well than the current standard. Methane emissions and rice yields were determined in field trials over two consecutive winter/spring seasons with continuously flooded and AWD irrigation treatments for 20 lowland rice varieties in the Mekong Delta of Vietnam. Based on the results, this paper investigates the magnitude of methane savings through varietal choice for both AWD and continuous flooding in relation to genotypic yields and explores potential options for compensating farmers' mitigation efforts. [ABSTRACT FROM AUTHOR]

With the water crisis affecting several countries, the use of innovative technologies and methods in irrigated agriculture is essential to increase water use efficiency. The use of magnetised water has been considered a possibility both for saving water resources and in increasing crop productivity and quality. Following this, the objective of the present study was to evaluate the growth and longevity of flower stems of ornamental sunflower (Helianthus annuus L.; Vincent's Choice) irrigated with different irrigation depths and water subjected to magnetic field treatment. The treatments consisted of five percentage of crop evapotranspiration (ETc) (20, 70, 100, 130, and 160% of ETc) and two types of irrigation water (magnetised water; and ordinary water). The following characteristics were evaluated: plant height, stem diameter, inflorescence diameter, fresh and dry masses of the leaves and stems, fresh and dry masses of the inflorescence, and post-harvest longevity of the flower stems. The growth and post-harvest longevity characteristics were not influenced by the water type. An increase in irrigation depth promoted an increase in all analysed parameters. Regarding the commercialisation patterns of cut flowers, depth equal to or greater than 0.7 ETc yielded the best classification of ornamental sunflower. [ABSTRACT FROM AUTHOR]

Identifying the irrigation-induced cooling effects from a particular plant species used for urban groundcovers while optimizing the rates of irrigation applications is important in regions with hot and dry summers. A 2-year (2020–21) study was conducted in Riverside, CA, USA, to evaluate the effect of irrigation rates on the canopy temperature dynamics of 10 urban groundcovers. Four reference evapotranspiration (ETo)-based irrigation treatments (20%, 40%, 60%, and 80% ETo) and 10 groundcovers were laid in a randomized complete block design and replicated three times. The effect of irrigation rates on the difference between canopy–air temperature (ΔT), leaf area index (LAI), and stomatal conductance (gs) were evaluated. All response variables were collected between May and October 2020 and 2021. The crop water stress index for five groundcovers was also computed. The ΔT was affected (P < 0.05) by irrigation rates, and groundcovers, including Rhagodia spinescens and Baccharis × ‘Starn Thompson’, maintained the canopy temperature less than the ambient air temperature for all irrigation rates imposed. For most of the groundcovers, the ΔT yielded a strong relationship with LAI (r = –0.41 to –0.73), and gs (r = –0.35 to –0.60). Crop water stress index also showed a strong correlation to normalized difference vegetation index (r = 0.42 to –0.72) and gs (r = –0.57 to –0.64). Irrigation-included cooling was evident in most groundcovers irrigated at higher rates; however, Rhagodia spinescens and Baccharis × ‘Starn Thompson’ were found to perform well in cooling ability and maintaining the canopy growth as evidenced by LAI. Our study showed that proper plant selection and irrigation management could help maintain green spaces and mitigate the urban heat island effect while conserving irrigation water. [ABSTRACT FROM AUTHOR]

The tomato crop is very sensitive to stress conditions. A water deficit is defined as when precipitation is less than the evapotranspiration (ETc) of the crop in a given period, and in this scenario of climate change, it is identified as responsible for global productivity losses. The use of potential technologies for better irrigation management, such as electromagnetically treated water, remains controversial. Thus, the objective of the present work was to investigate the effects of very low-frequency electromagnetic resonance field treatment on water for tomato crops submitted to different irrigation rates. For this, an experiment was carried out under controlled conditions with different types of water: electromagnetically treated water (WTVLF) and untreated water (UNW), as well as four water replacement rates: 40, 60, 80, and 100% ETc. The electromagnetic treatment of the water was carried out using the commercial equipment AQUA4D®. The experiment was carried out in pots with five replications per treatment. Lower activity of SOD, POD, CAT, and APX enzymes was observed in plants irrigated with water treated with very low-frequency electromagnetic resonance fields (WTVLF), indicating less oxidative stress caused by water deficit. Water deficit reduced chlorophyll content, but the effects were less harmful with WTVLF water. The water deficit resulted in less accumulation of dry matter and less productivity in a linear relationship. However, plants irrigated with WTVLF showed increments of about 20% in dry matter accumulation and 20% in fruit production concerning plants irrigated with untreated water, independent of the irrigation rates. We can conclude that irrigation with WTVLF can be a solution to reduce the damage caused by water deficits and increase the productivity of tomato crops. [ABSTRACT FROM AUTHOR]

Drought and climate change have decreased water availability for agriculture, especially in the desert of southwestern USA. Efficiency enhancements in irrigation management aimed at conserving water are key to adjust to limits in water supply, improve profitability and sustainability of alfalfa production in arid and semiarid areas. This study intended to conduct a field-scale analysis to develop yield and ET estimation tools for the effective use of irrigation water in a desert alfalfa production system. Extensive data collection and trials were carried out over three years in nine fully irrigated commercial alfalfa fields in the low deserts of California. The seasonal crop water consumption measured using the residual of energy balance method varied from 1381 mm to 1596 mm across the experimental sites and crop seasons. Variable seasonal dry mater (DM) yields ranged from 23.01 Mg ha−1 to 29.90 Mg ha−1. The results indicated that the first five cuttings each year were the most productive cuttings with a mean DM value ranged between 3.29 (cut 1) and 4.21 (cut 4) Mg ha−1 but declined in later cuttings. An average annual water productivity (WP) value of 17.0 kg ha−1 mm−1 was determined across the sites varying from 15.5 to 18.9 kg ha−1 mm−1. The findings suggested that one may lose up to 1.44 Mg ha−1 alfalfa yields with moderate summer deficit irrigation strategies, using 40% less water applied than full irrigation practices over the summer period of July–September. A more severe summer water deficit, with no irrigation event over the summer period of July–September may result in a potential water savings of 0.234–0.246 (ha·m) ha−1 and 19–21% seasonal yield losses in the desert environment. This study describes the seasonal yield pattern, the crop water use-production function, and the crop coefficient values for various harvest cycles over the crop season. These tools may assist farmers to quantify water savings and estimate yield losses for more accurate and effective irrigation management strategies to meet water conservation objectives and for the resiliency of alfalfa production in the desert region. [ABSTRACT FROM AUTHOR]

Global warming presents a significant threat to the sustainability of agricultural systems, demanding increased irrigation to mitigate the impacts of prolonged dry seasons. Efficient water management strategies, including deficit irrigation, have thus become essential, requiring continuous crop monitoring. However, conventional monitoring methods are laborious and time-consuming. This study investigates the potential of aerial imagery captured by unmanned aerial vehicles (UAVs) to predict critical water stress indicators—relative water content (RWC), midday leaf water potential (ΨMD), stomatal conductance (gs)—as well as the pigment content (chlorophyll ab, chlorophyll a, chlorophyll b and carotenoids) of trees in an olive orchard. Both thermal and spectral vegetation indices are calculated and correlated using linear and exponential regression models. The results reveal that the thermal vegetation indices contrast in estimating the water stress indicators, with the Crop Water Stress Index (CWSI) demonstrating higher precision in predicting the RWC (R2 = 0.80), ΨMD (R2 = 0.61) and gs (R2 = 0.72). Additionally, the Triangular Vegetation Index (TVI) shows superior accuracy in predicting the chlorophyll ab (R2 = 0.64) and chlorophyll a (R2 = 0.61), while the Modified Chlorophyll Absorption in Reflectance Index (MCARI) proves most effective for estimating the chlorophyll b (R2 = 0.52). This study emphasizes the potential of UAV-based multispectral and thermal infrared imagery in precision agriculture, enabling assessments of the water status and pigment content. Moreover, these results highlight the vital importance of this technology in optimising resource allocation and enhancing olive production, critical steps towards sustainable agriculture in the face of global warming. [ABSTRACT FROM AUTHOR]

Improving cotton (Gossypium hirsutum L.) yield and water use efficiency (WUE) under future climate scenarios by optimizing irrigation regimes is crucial in hyper-arid areas. Assuming a current baseline atmospheric carbon dioxide concentration ( C O 2 a t m ) of 380 ppm (baseline, BL0/380), the Root Zone Water Quality Model (RZWQM2) was used to evaluate the effects of four climate change scenarios—S1.5/380 ( ∆ T a i r ° = 1.5   ° C , ∆ C O 2 a t m = 0 ), S2.0/380 ( ∆ T a i r ° = 2.0   ° C , ∆ C O 2 a t m = 0 ), S1.5/490 ( ∆ T a i r ° = 1.5   ° C , ∆ C O 2 a t m = + 110   p p m ) and S2.0/650 ( ∆ T a i r ° = 2.0   ° C , ∆ C O 2 a t m = + 270   p p m ) on soil water content (θ), soil temperature ( T s o i l ° ), aboveground biomass, cotton yield and WUE under full irrigation. Cotton yield and irrigation water use efficiency (IWUE) under 10 different irrigation management strategies were analysed for economic benefits. Under the S1.5/380 and S2.0/380 scenarios, the average simulated aboveground biomass of cotton (vs. BL0/380) declined by 11% and 16%, whereas under S1.5/490 and S2.0/650 scenarios it increased by 12% and 30%, respectively. The simulated average seed cotton yield (vs. BL0/380) increased by 9.0% and 20.3% under the S1.5/490 and S2.0/650 scenarios, but decreased by 10.5% and 15.3% under the S1.5/380 and S2.0/380 scenarios, respectively. Owing to greater cotton yield and lesser transpiration, a 9.0% and 24.2% increase (vs. BL0/380) in cotton WUE occurred under the S1.5/490 and S2.0/650 scenarios, respectively. The highest net income ($3741 ha−1) and net water yield ($1.14 m−3) of cotton under climate change occurred when irrigated at 650 mm and 500 mm per growing season, respectively. These results suggested that deficit irrigation can be adopted in irrigated cotton fields to address the agricultural water crisis expected under climate change. [ABSTRACT FROM AUTHOR]

Copyright of Revista Caatinga is the property of Revista Caatinga 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 deficit can limit maize yield; therefore, appropriate choices of irrigation schemes or water-saving irrigation strategies to maximize WUE are needed for sustainable agriculture in response to environmental challenges and climate change. The objectives of our study were to evaluate and compare the effects of regulated deficit irrigation (RDI) and partial root-zone drying irrigation (PRDI) schemes with various field capacity (FC) conditions on yield components, water use efficiency (WUE), photosynthesis capacity, and chlorophyll fluorescence parameters of the maize plant in a pot experiment. Moreover, we also investigated foliar application of glycine betaine (B, 50 mM) and soil-treated chitin (C, 2 g/kg) to plants against water supply limitations and highlighted their potential for the sustainable production of maize. Significantly higher plant height, cob fresh and dry weights, and total dry weight of maize were observed in RDI with the 75 % FC condition compared to the control (full irrigation with 100 % FC). PRDI treatment resulted in significantly higher economic yield, WUE yield , and WUE biomass compared to RDI treatment. Total water used in PRDI at 50 % FC saved 72 % of water resources compared to the control. Furthermore, values for effective quantum yield (ФPSII), photochemical quenching (qP), and electron transfer rate (ETR) of maize subjected to 75 % FC were higher than under 50 % FC and the control, while maximal quantum efficiency (Fv/Fm) levels of maize were higher under 50 % FC than under 75 % FC. All agronomic traits, chlorophyll content (as SPAD value), transpiration rate, net photosynthesis value, WUE yield , and WUE biomass of plants subjected to PRD-50 %FC with spraying B alone showed higher values compared to other chemical applications and no chemical treatment. Applying C alone to maize plants under PRDI-50 % FC increased qP and Fv/Fm compared to other chemical treatments. Evaluating water deficits with non-destructive measurements are applicable to large-scale water management of maize plants, thereby enabling scarce water resources to be conserved. [ABSTRACT FROM AUTHOR]

Copyright of Scientific Journal of Agricultural Sciences (SJAS) is the property of Beni Suef University 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.)

Olive groves in the Mediterranean may lose production sustainability because of their vulnerability to climatic change. Irrigation is an important measure that could significantly affect fruit yield, olive fruit fly infestation, and oil characteristics. The aim of paper was to compare the regulated deficit irrigation with different water management practices, in consecutive years, in two locations in Zadar County (Croatia), affecting fruit morphology, olive fruit fly infestation, and quantity and quality of the extracted Coratina cultivar oil. Treatments, namely C—rainfed, T1—deficit irrigation (produce's practice), T2—regulated deficit irrigation, and T3—full irrigation (100% ECTO), were established. Irrigated treatments had a positive effect on all morphological characteristics of the fruit. The pulp mass, independently of the year, increased in irrigated treatment (ranging from 1.04 to 1.65 in C to 2.25 and 2.30 in the irrigated treatments) and resulted in a higher oil content on a fresh weight basis (ranging from 16.39% to 17.85% in C to 19.48% to 23.26% in the irrigated treatments). However, fruit yield per tree was only location-dependent. When olive fruit fly presence was high, fruit infestation was greatest in the irrigated compared to the rainfed treatment. According to quality parameters, all oils were classified as EVOO. Individual phenols were influenced by irrigation, while the composition of fatty acids was more influenced by location than treatment. The sensory characteristics of the resulting oil were slightly reduced compared to rainfed treatment. The results indicate that regulated deficit irrigation benefits water use sustainability without compromising the quality of the oil. [ABSTRACT FROM AUTHOR]

Water scarcity is one of the main abiotic factors that limit agricultural production. In this sense, the identification of genotypes tolerant to water deficit associated with irrigation management strategies is extremely important. In this context, the objective of this study was to evaluate the morphology, production, water consumption, and water use efficiency of colored fiber cotton genotypes submitted to irrigation strategies with a water deficit in the phenological phases. Two experiments were conducted in succession. In the first experiment, a randomized block design was used in a 3 × 7 factorial scheme, corresponding to three colored cotton genotypes (BRS Rubi, BRS Jade, and BRS Safira) in seven irrigation management strategies with 40% of the real evapotranspiration (ETr) varying the phenological stages. In the second experiment, the same design was used in a 3 × 10 factorial arrangement (genotypes × irrigation management strategies). The water deficit in the vegetative phase can be used in the first year of cotton cultivation. Among the genotypes, 'BRS Jade' is the most tolerant to water deficit in terms of phytomass accumulation and fiber production. [ABSTRACT FROM AUTHOR]

Microbial pollution of the groundwater and surface waters could endanger animal and human health as a serious environmental issue. Escherichia coli retention was investigated in the sandy loam columns amended with biochar under deficit irrigation (60%, 80%, 100%, and 120% of the field capacity). A pulse of bacteria (1.00 × 108 CFU ml–1) was poured on the soil surface. Two scenarios were conducted using HYDRUS-1D. The retention rate in all treatments at 0–10 cm was higher than the depths of 10–30. This was more significant in amended soil compared to the control soils. The first scenario (attachment, katt or straining, kstr) showed that katt values were at least 25 times greater than the kstr values, indicating that the physico-chemical process was dominant compared to the physical retention in both biochar treated and the control soils. The katt values calculated for the biochar-treated columns were increased as the deficit irrigation increased. The second scenario (physico-chemical, kdet2 or physical, kdet1 detachment) illustrated no significant difference between the kdet values in both sites, while the kdet2 values of the amended soil were less than the controls, indicating the contribution of biochar in cell attachment. Obvious greater values of katt compared to kstr approved the first scenario determining the fact that biochar's land application under deficit irrigation most probably enhances cell retention via attachment than straining. [ABSTRACT FROM AUTHOR]

Citrus is one of the most valuable crops in Syria, with the largest production areas being in the coastal provinces of Tartus and Latakia, where this study was performed. A companion paper reported on the basal crop coefficients derived from the field water balance and on the performance assessment of various irrigation methods used in a citrus orchard located in the same region. That study evidenced the need for the improved management of irrigation water, mainly reducing water applications and increasing productivity, thus leading to the current research. The main objectives consisted of (i) providing a set of reliable basal (Kcb) and average (Kc) crop coefficients to be used in practice in the citrus orchards of the Syrian coastal area, while accounting for the diversity of characteristics observed; (ii) to estimate the seasonal consumptive use of typical orchards under different climate-demand and deficit-irrigation scenarios; and (iii) to assess possible water savings and related yield reductions. The previously calibrated water balance model SIMDualKc was used for these purposes. The computed Kcb values for the mid-season and average demand for water ranged from 0.52, when the plant density was low, to 0.84, when plant density was very high. The corresponding Kc values, which further reflected the impact of drip irrigation on controlling soil evaporation, were 0.72 and 0.97, respectively. Overall, the consumptive use of water was estimated to range from 867 to 1573 mm. The assessed water-saving scenarios consisted of adopting increased management-allowed depletion (MAD) thresholds relative to the p depletion fraction for no stress: MAD = 1.05, 1.10, 1.20, and 1.30 p. For trees under a very high climatic demand, water savings ranged from 12 to 34%, but the yield losses induced by the water deficits ranged from 8 to 48%. Although the selection of optimal strategies should be based upon economic terms, these may only be used when the Syrian economy recovers from civil war and the current crisis. The present results show the feasibility of adopting such MAD thresholds for building an irrigation management platform. The data provided by the current study are valuable because they can be efficiently used to support of the irrigation management of Syrian citrus production systems. [ABSTRACT FROM AUTHOR]

Cherries are rich in nutrients and have high economic benefits from their wide range of applications in the food industry and drug development. To save the use of water resources and, at the same time, to get the optimal crop economic efficiency, the study was conducted on the greenhouse cultivation of cherries, taking into account transpiration, to calculate the amount of irrigation in order to get the best yield and quality of cherries and at the same time to consume the least amount of water resources. Firstly, greenhouse transpiration and the factors affecting it were tested. The results showed that cherry transpiration varied rapidly at higher ambient humidity in the room with daily transpiration variations kept within 150 g. The cherries were able to maintain a low level of transpiration when the average daily relative air humidity was greater than 80%. The irrigation amount was then calculated according to the daily transpiration of cherries. The results showed that the yield was 2.83 kg/plant in 120% daily transpiration treatment, which was 23.9%, 11.1%, and 3.2% higher than that in 80%, 100%, and 140% treatments, respectively. 80% transpiration treatment had the highest water utilization efficiency of 39.6 kg/m³, while the lowest irrigation water utilization efficiency was 26.9 kg/m³ in 140% transpiration treatment. The study demonstrated that irrigation at 120% evapotranspiration resulted in the best fruit quality, while 140% evapotranspiration treatment resulted in the lowest total fruit quantity and quality. The findings not only provided a scientific basis for irrigation management of cherry, but also might provide a valuable reference for irrigation research of other crops. [ABSTRACT FROM AUTHOR]

Due to water scarcity, it is impossible to utilize all irrigated cropland in arid and semi-arid areas. Therefore, dense cultivation with a drip irrigation system that delivers water directly to the plant's root zone is an appropriate choice to enhance water productivity. The objectives of the present study were to compare wheat yield and water productivity under two different water distribution patterns in the drip-tape irrigation system and surface irrigation in full irrigation and deficit irrigation levels. The experimental treatments consist of two irrigation systems (drip-tape (DT), and surface irrigation (SU)), and three different irrigation levels (a full irrigation level (W1), two deficit irrigation levels, the irrigation interval twice, and the same irrigation depth of W1 level (W2), applied half of the irrigation depth of W1 level at the same time (W3)). The SU was implemented in place with 100% efficiency to avoid runoff. The yield in full irrigation level in DT was 5338.4 kg/ha and in SU was 5772.8 kg/ha. Applying deficit irrigation in two irrigation systems has different effects due to various water distribution patterns. In the DT, the most yield reduction was in W2, and in SU was in W3. The highest water productivity in DT was observed in W3 with a 1.44 kg/m³ value. The highest water productivity in SU was observed in W2 with a 1.46 kg/m3 value. For each irrigation system, some type of deficit irrigation management is optimal. [ABSTRACT FROM AUTHOR]

Increasing scarcity and unreliability of rainfall, and the absence of irrigation schedules are challenges to decision-making, particularly for viable tomato (Lycopersicon esculentum Mill) production in Zimbabwe. The objective of this study was to determine water requirements of tomato as a basis for developing generic calendar guidelines for a more efficient irrigation management in Harare, Zimbabwe. We explored the options of improving the traditional, dry and supplementary wet season irrigation practices. By considering the archived climate data of thirty years (1991-2021) for Harare; and modelsimulated consumptive water use from 2014 to 2017 at Thornpark Research Station, together with the crop and soil characteristics; and the irrigation method; an irrigation calendar was developed using the AquaCrop model 5.0. The improved irrigation schedule for dry season tomato cultivation at 60% ETc, resulted in water use of 471.6 mm, with a yield of 3.40 t ha-1; compared to water use of 820 mm and a yield of 1.118 t ha-1; for the wet season. Through this model, we have been able to estimate the time interval between the previous irrigation and the next irrigation for any date in the growing season. Therefore, year-round irrigated tomato production may be feasible with an added yield advantage of 2.28 t ha-1 obtainable using water and rainy periods. [ABSTRACT FROM AUTHOR]

The production of olive oil in Portugal and other countries of the Mediterranean region has greatly increased in recent years. Intensification efforts have focused on the growth of the planted area, but also on the increase of the orchards density and the implementation of irrigation systems. Concerns about possible negative impacts of modern olive orchard production have arisen in the last years, questioning the trade-offs between the production benefits and the environmental costs. Therefore, it is of great importance to review the research progress made regarding agronomic options that preserve ecosystem services in high-density irrigated olive orchards. In this literature review, a keywords-based search of academic databases was performed using, as primary keywords, irrigated olive orchards, high density/intensive/hedgerow olive orchards/groves, irrigation strategies, and soil management. Aside from 42 general databases, disseminated research, and concept-framing publications, 112 specific studies were retrieved. The olive orchards were classified as either traditional (TD) (50–200 trees ha−1), medium-density (MD) (201–400 trees ha−1), high-density (HD) (401–1500 trees ha−1), or super-high-density (SHD) orchards (1501–2500 trees ha−1). For olive crops, the crop coefficient (Kc) ranges ranges from 0.65 to 0.70, and can fall as low as 0.45 in the summer without a significant decrease in oil productivity. Several studies have reported that intermediate irrigation levels linked with the adoption of deficit irrigation strategies, like regulated deficit irrigation (RDI) or partial rootzone drying (PRD), can be effective options. With irrigation, it is possible to implement agroecosystems with cover crops, non-tillage, and recycling of pruning residues. These practices reduce the soil erosion and nutrient leaching and improve the soil organic carbon by 2 to 3 t C ha−1 year−1. In this situation, in general, the biodiversity of plants and animals also increases. We expect that this work will provide a reference for research works and resource planning focused on the improvement of the productive and environmental performance of dense irrigated olive orchards, thereby contributing to the overall enhancement of the sustainability of these expanding agroecosystems. [ABSTRACT FROM AUTHOR]

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Volumetric soil water content is commonly used for irrigation management in fruit trees. By integrating direct information on tree water status into measurements of soil water content, we can improve detection of water stress and irrigation scheduling. Thermal-based indicators can be an alternative to traditional measurements of midday stem water potential and stomatal conductance for irrigation management of pear trees (Pyrus communis L.). These indicators are easy, quick, and cost-effective. The soil and tree water status of two cultivars of pear trees 'D'Anjou' and 'Bartlett' submitted to regulated deficit irrigation was measured regularly in a pear orchard in Rock Island, WA (USA) for two seasons, 2021 and 2022. These assessments were compared to the canopy temperature (Tc), the difference between the canopy and air temperature (Tc-Ta) and the crop water stress index (CWSI). Trees under deficit irrigation had lower midday stem water potential and stomatal conductance but higher Tc, Tc-Ta, and CWSI. Tc was not a robust method to assess tree water status since it was strongly related to air temperature (R = 0.99). However, Tc-Ta and CWSI were greater than 0°C or 0.5, respectively, and were less dependent on the environmental conditions when trees were under water deficits (midday stem water potential values< -1.2 MPa). Moreover, values of Tc-Ta = 2°C and CWSI = 0.8 occurred when midday stem water potential was close to -1.5 MPa and stomatal conductance was lower than 200 mmol m-2s-1. Soil water content (SWC) was the first indicator in detecting the deficit irrigation applied, however, it was not as strongly related to the tree water status as the thermal-based indicators. Thus, the relation between the indicators studied with the stem water potential followed the order: CWSI > Tc-Ta > SWC = Tc. A multiple regression analysis is proposed that combines both soil water content and thermal-based indices to overcome limitations of individual use of each indicator. [ABSTRACT FROM AUTHOR]

Water plays a very important role in the growth of tomato (Solanum lycopersicum L.), and how to detect the water status of tomato is the key to precise irrigation. The objective of this study is to detect the water status of tomato by fusing RGB, NIR and depth image information through deep learning. Five irrigation levels were set to cultivate tomatoes in different water states, with irrigation amounts of 150%, 125%, 100%, 75%, and 50% of reference evapotranspiration calculated by a modified Penman-Monteith equation, respectively. The water status of tomatoes was divided into five categories: severely irrigated deficit, slightly irrigated deficit, moderately irrigated, slightly over-irrigated, and severely over-irrigated. RGB images, depth images and NIR images of the upper part of the tomato plant were taken as data sets. The data sets were used to train and test the tomato water status detection models built with single-mode and multimodal deep learning networks, respectively. In the single-mode deep learning network, two CNNs, VGG-16 and Resnet-50, were trained on a single RGB image, a depth image, or a NIR image for a total of six cases. In the multimodal deep learning network, two or more of the RGB images, depth images and NIR images were trained with VGG-16 or Resnet-50, respectively, for a total of 20 combinations. Results showed that the accuracy of tomato water status detection based on single-mode deep learning ranged from 88.97% to 93.09%, while the accuracy of tomato water status detection based on multimodal deep learning ranged from 93.09% to 99.18%. The multimodal deep learning significantly outperformed the single-modal deep learning. The tomato water status detection model built using a multimodal deep learning network with ResNet-50 for RGB images and VGG-16 for depth and NIR images was optimal. This study provides a novel method for non-destructive detection of water status of tomato and gives a reference for precise irrigation management. [ABSTRACT FROM AUTHOR]