General Background: Sustainable agriculture increasingly relies on soil amendments that improve physical properties and resource efficiency. Specific Background: Zeolites—hydrated crystalline aluminosilicates—are recognized for their high porosity, cation exchange capacity, and water retention, making them valuable in soil management. Knowledge Gap: Despite broad applications, a comprehensive understanding of zeolite's role in enhancing physical soil properties across various textures under field conditions remains limited. Aims: This review investigates zeolite’s influence on soil bulk density, porosity, water retention, and overall plant productivity, particularly under water stress. Results: Findings from multiple field and laboratory studies reveal that zeolite addition improves water-holding capacity, reduces soil bulk density, enhances total porosity, and increases crop yield and water use efficiency. Novelty: The synthesis of recent evidence demonstrates that zeolites not only act as soil conditioners but also serve as strategic tools in mitigating water stress and optimizing nutrient use, outperforming other soil amendments such as biochar under similar conditions. Implications: These insights support integrating zeolite into sustainable soil management practices to bolster agricultural resilience in arid and semi-arid environments, aligning with global efforts toward resource-efficient and climate-adaptive farming systems.Highlight : Water Use Efficiency: Zeolites improve soil's ability to retain water, significantly benefiting crops under drought or limited irrigation. Soil Structure Enhancement: They reduce bulk density and increase porosity, enhancing root growth and nutrient movement. Nutrient Management: Zeolites act as slow-release reservoirs, increasing nutrient availability while minimizing leaching. Keywords : Zeolites, Soil Conditioner, Water Retention, Nutrient Efficiency, Sustainable Agriculture

This study was conducted to evaluate the performance of sweet pepper (Capsicum annuum L.) under different irrigation levels and systems, with the aim of optimizing water use efficiency and improving crop productivity under field conditions in central Iraq. The field experiment was carried out in Al-Yusufiyah, Baghdad Governorate, using a randomized complete block design (RCBD) with a factorial arrangement of three irrigation levels (I1: 100%, I2: 75%, and I3: 50% of crop water requirement) and two irrigation systems (furrow and surface drip irrigation). The experimental plot covered an area of approximately 2000 m², and Modesto sweet pepper seedlings were transplanted and monitored over a 173-day growing season. Results showed that surface drip irrigation significantly reduced seasonal water consumption compared to furrow irrigation, with a 21% decrease at the same irrigation level. The highest water consumption was recorded under furrow irrigation (622 mm at I2), whereas the lowest was under drip irrigation (350 mm at I3). Surface drip irrigation improved plant height, stem thickness, and total yield, particularly under moderate water stress (I2). Plant height reached 110 cm under I1 and 103 cm under I2 in the drip system, with no significant differences between the two. Total yield peaked at 80 t·ha⁻¹ under I1 in the drip system, which was not statistically different from I2 (76 t·ha⁻¹), despite a substantial reduction in water input. Water use efficiency (WUE) was also significantly higher under drip irrigation, with values of 12.6, 15.4, and 13.7 kg·m⁻³ for I1, I2, and I3, respectively, compared to 9.4, 10.6, and 8.9 kg·m⁻³ under furrow irrigation. These improvements were attributed to better root zone moisture retention, enhanced nutrient availability, and reduced water losses through evaporation and deep percolation. The findings highlight the potential of surface drip irrigation, particularly at 75% irrigation level (I2), as a sustainable strategy for improving water productivity and maintaining high yields of sweet pepper under water-limited conditions. This is the first documented estimation of the seasonal water requirement of sweet pepper in central Iraq under open-field conditions.

A field experiment was conducted to grow lettuce (Lactuca sativa L.) during the 2021-2022 season in Al-Yusufiyah district, south of Baghdad, to study the effect of irrigation levels and spraying with proline acid on water requirements, growth and production of lettuce. The experiment was designed using a complete randomized block design (RCBD) and included two factors: the first factor (irrigation levels) includes three treatments (irrigation after depletion 25, 40 and 55% of the available water) and the second factor (concentrations of adding proline acid sprayed on the leaves) includes three treatments (not adding proline and adding proline sprayed on the leaves at a concentration of 40 and 80 mg L-1). The results of the study were as follows: Seasonal water consumption reached 262, 233 and 186 mm for the moisture depletion treatments of 25, 40 and 55% of the available water, respectively, under the drip irrigation system. The total vegetative yield of lettuce was 247.67, 215.10 and 171.73 μg ha-1 at 25, 40 and 55% depletion levels of available water, respectively. The total yield of lettuce was 258.30, 228.50 and 181.40 μg ha-1 at 25, 40 and 55% depletion levels of available water, respectively, when spraying proline acid at a concentration of 80 mg L-1.

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.