Soil moisture retention and performance of different irrigation practices for wheat crop grown on clay loam soil

An experimental field was carried out during the growing season of 2019/20 and 2020/21 at The Experimental Farm, Fac. of Agriculture, Assiut, Egypt (27° 12- 16.67= N latitude and 31° 09- 36.86= E longitude) in order to evaluate the change in soil moisture retention and wheat plant response to different irrigation practices as well as their performances and water productivity. The tested irrigation practices (border, furrow, alternative furrow, gated pipe and surface drip) were arranged as factorial in a completely randomized design with three replicates. The soil moisture retention decreased clearly with soil depth for all irrigation practices through both seasons. On average basis of both seasons, the soil water retained in 60 cm soil depth was 12.36, 12.17, 11.99, 11.91 and 11.75 cm water depth for basin, furrow, alternative furrow, gated pipe and drip irrigation practices, respectively. It could be arranged the amount of retained water in descending order of basin > furrow > alternative furrow > gated pipe > drip irrigation practices. In general, it was noticed that the retained water in the top layer (0- 30 cm) was higher than that in sub layer (30- 60 cm). On average basis of both seasons, the relative increases in soil water retention in 60 cm soil depth were 3.79, 3.60, 2.00 and 1.40% for basin, furrow, alternative furrow and gated pipe, respectively compared to drip irrigation practice. The irrigation performance indices of gated pipe and drip irrigation were utmost the other irrigation practices. Water application efficiency, the non-beneficial water consumption, water storage efficiency and distribution uniformity was 84.15 and 85.29%, 18.85 and 17.25%, 58.04 and 56.15% and 90.68 and 90.90 for gated pipe and drip irrigation practices, respectively. The highest wheat grain and straw yield were attained at gated pipe and drip irrigation practices since grain yield was 3164.0 and 3113.0 kg/ fed. and straw yield was 3691.5 and 3646.0 kg/fed., respectively. It might be concluded that applying more irrigation water than can be stored in the top 60 cm of the soil profile will result in inefficient utilization of this water by winter wheat. Selection of a suitable irrigation method would depend on the specific conditions of water resources, crop types and management requirements.