The role of limited irrigation and advanced management on improving water productivity of rainfed wheat at semi-cold region of upper Karkheh River Basin, Iran

Abstract

In order to evaluate the role of a limited irrigation (LI) and agronomic management on improving rain water productivity, a field study was conducted during 2005-08 winter cropping seasons of wheat at multiple farms across benchmark watershed of Honam (Lorestan Province) in the upper Karkheh River Basin (KRB), Iran. limited irrigation consist of four treatments; single irrigation (SI) at planting time, single irrigation at spring time, two times irrigation (planting time and spring) and Rainfed, and so agronomic management practices consist of two treatments: traditional and advanced management (TM and AM), were evaluated. The results of this study showed that under rainfed conditions, wheat grain yield of AM (2321 kg ha-1) increased by 34.5% as compared to TM (1726 kg ha-1). At Honam site, the optimum program was obtained by a combination of advanced agronomic management package with SI options (irrigation at planting time/spring time), in which the maximum water productivity and net benefit were obtained. The advanced agronomic management (AM) had better performance as compared to traditional management. At rainfed conditions, WP of traditional management (0.35 kg m-3) increased by 28.6% as compared to advanced management (0.45 kg m-3). The results of this study showed that a single irrigation application at sowing or spring time (during heading to flowering stage) increased total water productivity (TWP) of wheat to a range of 0.57 to 0.63 kg m-3 during average three seasons. The average irrigation water productivity (IWP) of wheat reached a range of 2.15-3.26 kg m-3 by using single irrigation at sowing or spring time. Low WP (and yield) in farmers’ practices of rainfed conditions, were mainly due to suboptimal agronomic management practices. These preliminary results confirm the potential of single irrigation and early/normal planting as an effective method to enhance productivity.