Modeling the effect of tillage and irrigation management on water and barley productivity for different soil textures

In arid and semi-arid regions, crop production is still limited by water scarcity and poor field management. To overcome these challenges, it is essential to discover effective agricultural practices that make the most of limited water availability and preserve soil nutrients. This study aimed to discover the best combination of tillage practices, irrigation systems, and soil textures that could promote the sustainable productivity of irrigation water and barley crop using the Root Zone Water Quality Model (RZWQM2). To achieve the study objective, an experiment was conducted in a barley growing seasons of 2020-2021 and 2021-2022 in Baghdad, Iraq, using sprinkler and flooding irrigation systems, as well as conservation (field cultivator) and conventional (moldboard plowing) tillage practices on two types of soil textures: silty clay and sandy clay. The results indicate that, RZWQM2 satisfactorily captures the combination effects of field practices on water-barley productivity in different soil textures. The behavior of soil water-nitrate dynamics, crop development, and water consumption presented a noticeable response to the combination of experimental factors. When sprinkler irrigation was utilized, sandy clay soil was more responsive to field practices than silty clay soil by about 6-12 %. The moldboard plowing practice increased crop development and yield by about 5-10 % compared to the field cultivator practice. The combination of sandy clay soil, sprinkler irrigation, and moldboard plowing yielded more satisfactory results of water use efficiency and crop productivity. Generally, for both soil texture types, moldboard plowing tillage showed satisfactory results compared to the field cultivator tillage.