Deficit irrigation strategies to improve winter wheat productivity and regulating root growth under different planting patterns

Abstract

Soil moisture status and knowledge of rooting systems are essential for improving winter wheat productivity in the semiarid areas. The ridge-furrow rainfall harvesting (RI) system in combination with deficit irrigation is the key strategy for improving winter wheat productivity. Therefore, a research trail we conducted during 2015–16 and 2016–17, on RI system where the amount of irrigation was decreased by half due to the rainfall harvesting, than that of traditional boarder irrigation (BI). The following two planting patterns were used (1) the RI system with (75, 37, 18, 0 mm) irrigation levels, and (2) BI planting pattern with (150, 75, 37, 0 mm) deficit irrigation levels. Results showed that under the RI75 treatment soil water and soil respiration in topsoil increase significantly ; whereas there was reduction in ET rate that was (44.2%) and soil temperature; thus, therefore and the morphology of winter wheat rooting system owing to significant improvement in grain yield (14.6%) and WUE (64.8%) as compared to BI150 treatment. This treatment improved wheat root tissue density (4.9%), root length ratio (16.3%), root mass ratio (8.3%) and root fineness (9.5%) as compared with conventional border irrigation. The RI75 treatment produced significantly greater RWD, RLD, and RSD at 10–40 cm soil depth when compared with BI150 treatment. The RI system increased the root bleeding sap rate and root dry weight as compared to BI planting pattern. Therefore, the RI system combined with 75 mm deficit irrigation can be an efficient water saving strategy in semi-arid regions due to increased soil moisture across the rooting zones, a resulting in higher WUE and wheat production.