Modeling achievable yield under water-limiting environments is an imperative goal in arid, semi-arid, and drought-prone locations. This study aimed to calibrate the AquaCrop model simulation based on experience gained at al-Hashimiya District, 20 km east of Babylon, Iraq. Wheat (Triticum aestivum) in 2016–2017 and 2017–2018 was grown using deficit irrigation systems (surface and sprinkler irrigation) and different tillage methods (deep, moderate, and zero tillage). A simulation was conducted on the systems, using climate data for a period of 10 years and specific data on the study area, crops grown, and irrigation types. Then, statistical analysis was conducted with the root-mean-square error (RMSE), which refers to compatibility between the results and predictions of the measured values. For 2016–2017 and 2017–2018, RMSE values were 0.764 and 0.643 for biomass, 0.473 and 0.419 for dry matter, 0.141 and 0.154 for water productivity, and 1.59 and 0.946 for harvest index. The R2 values were 0.917 and 0.956 for dry matter, 0.982 and 0.946 for biomass, 0.869 and 0.849 for harvest index, and 0.923 and 0.943 for water productivity from 2016–2017 and 2017–2018. Mean bias error (MBE) and mean absolute error (MAE) were also derived with comparable results. The model results indicated that there is an explicit agreement with the simulated values of the wheat crop. The AquaCrop model can be used to estimate water productivity, dry matter, and biomass to improve agricultural water management and as an input into future research of alternate forms of irrigation.

Afield trial was conducted at Al- Hashimya area, Babylon district, Iraq during the growing seasons 2016-2017 and 2017-2018 to investigate the effect of some agronomic practices viz. irrigation system ( sprinkler irrigation (I1) and surface irrigation (I2) which occupied the main plots; tillage system (Zero tillage (T0), minimum tillage (T1) and deep tillage (T2) which occupied the subplot ); and seeding rates (120 Kg ha-1( S1), 180 Kg ha-1(S2),240 Kg ha-1 (S3)and 300 Kg ha-1 (S4) which occupied the sub _ subplots on biological yield, harvest index, water _use efficiency, water consumptive use, crop coefficient of bread wheat (Triticum aestivum L.). Results indicated that biological yield was increased in both seasons by 9 and 10%, respectively, following the application of sprinkler irrigation. This may be due to the increased water _use efficiency by 29 and 32% in both seasons, respectively, as influenced by sprinkler irrigation. However, sprinkler irrigation did not affect the harvest index in both seasons. Similarly, minimum tillage increased the biological yield by 10.6,10.2,11.8 and 3.4 % over zero _ tillage and deep tillage in both seasons, respectively. However, the tillage system had no significant effect on the harvest index in both seasons. The seeding rate (240 Kg ha-1) increased the biological yield by 15.1 and 16.0 % over the lowest seeding rate (S1 120 Kg ha-1) with no significant effect on the harvest index in both seasons, respectively. The exciting result that the application of sprinkler irrigation (I1) decreased the consumptive use mm. Season in both seasons and consequently the crop coefficient (Kc) was decreased at tillering, elongation, flowering and maturity stages in both seasons. It can be concluded that the application of sprinkler irrigation under the minimum tillage and using the seeding rate 240 Kg ha-1 has increased the biological yield via increased water – use efficiency and decreased both consumptive use and crop coefficient.

A field experiment was conducted with the aim of knowing the effect of different depletion levels of ready water and different levels of phosphate fertilization on the water consumption of lettuce crop, yield coefficient and some characteristics of lettuce plant. (30,60,80) % And the addition of...

Water management is critical for agricultural productivity in semi-arid regions, where water availability is limited and evaporation is high. This study presents a comparative evaluation of the Rafidain and Valley center pivot irrigation systems in southwestern Karbala. Each system was tested using three tower configurations (T3, T4, and T6) under operating pressures of 150, 200, and 250 kPa, assessing irrigation efficiency, water distribution uniformity, and soil moisture retention. Results showed a consistent performance trend in both systems, with peak irrigation efficiency at 200 kPa. The Valley system exhibited slightly higher efficiencies than the Rafidain system across all pressures, particularly at 200 kPa, where VT6 and RT6 achieved 86.49% and 85.34%, respectively. Soil moisture analysis indicated that soils under the Valley pivots retained more available water at all suction levels than Rafidain soils. These findings highlight the sensitivity of center pivot performance to operating pressure and confirm that 200 kPa optimizes water use efficiency, distribution uniformity, and root-zone moisture availability. The study provides practical guidance for system-specific management to support sustainable irrigation in semi-arid environments.

In arid and semi-arid regions, furrow irrigation is a common method for okra cultivation, but water losses reduce its efficiency. Alternate furrow irrigation has been shown to conserve water without yield reduction, while nitrogen fertilization plays a key role in enhancing vegetative growth and productivity. Since okra yields in Iraq remain low due to poor irrigation scheduling and imbalanced fertilizer use, optimizing water and nitrogen management is crucial for sustainable production. Therefore, a field experiment was conducted in Abi Ghraq sub-district, Babylon Province, Iraq, during the 2024 growing season to evaluate the effects of furrow irrigation methods (conventional, fixed, and alternate) and nitrogen fertilizer levels (160, 240, and 480 kg N/ha) on okra yield and water productivity. The study was carried out on a silty clay loam soil with moderate fertility and an electrical conductivity of 2.11 dS/m. Results revealed that alternate furrow irrigation significantly improved water usage efficiency and pod yield compared to conventional and fixed furrow systems. The highest cumulative pod yield (6.42 t/ha) and water productivity (2.40 kg/m³) were recorded under alternate furrow irrigation combined with the highest nitrogen level (480 kg N/ha). Increasing nitrogen levels led to marked improvements in vegetative growth, photosynthetic activity, and ultimately pod development, especially when supported by balanced fertilisation with phosphorus and potassium. The findings demonstrate that alternate furrow Irrigation, in conjunction with appropriate nitrogen fertilisation, can reduce irrigation water use by up to 35% while maintaining or enhancing okra yield. This integrated approach offers a practical and sustainable solution for improving crop productivity and resource use efficiency in fine-textured soils of arid and semi-arid regions.