EFFECT OF ZERO-TILLAGE FARMING SYSTEMS ON SOIL PHYSICAL PROPERTIES, GROWTH, AND YIELD OF WHEAT UNDER DIFFERENT IRRIGATION SYSTEMS IN AL-YUSUFIYA, CENTRAL IRAQ

Abstract

Rapid population growth in arid and semi-arid regions, coupled with rising living standards, has intensified the demand for food. Wheat (Triticum aestivum L.) is a strategic crop for food security in Iraq and other semiarid countries, where efficient water and soil management are essential for sustainable production. A field experiment was conducted during the 2023–2024 growing season in a farmer’s field located in the Yusufiyah region, approximately 15 km southwest of Baghdad, Iraq (33°07′84″ N, 44°18′75″ E, 34.1 m a.s.l.). The study evaluated the effects of three irrigation systems (sprinkler, drip, and surface), three seed rates (30, 40, and 50 kg/ha), and three tillage systems (disc opener, chisel opener, and broadcaster) on wheat growth, yield, soil physical properties, and irrigation efficiency. The results demonstrated that plant height was significantly influenced by irrigation and tillage, with the sprinkler–chisel combination producing the tallest plants. Grain yield, biological yield, and harvest index were not significantly affected, reflecting stability across treatments and offering management flexibility. Soil porosity improved significantly under sprinkler irrigation and chisel tillage, while soil penetration resistance remained unchanged, indicating minimal compaction differences. Irrigation efficiency analysis revealed that sprinkler performance increased with operating pressure, while drip irrigation achieved optimal efficiency at ~100 kPa. vegetative growth was more responsive to irrigation and tillage practices than yield components, which remained stable across management factors. Chisel tillage enhanced soil porosity without increasing compaction, and efficient irrigation management improved water use efficiency. It is recommended that farmers in semi-arid regions adopt sprinkler irrigation combined with chisel tillage to improve plant growth and soil structure, while drip irrigation should be managed at moderate pressure (~100 kPa) to optimize efficiency and conserve water resources.