Limited irrigation influence on rotation yield, water use, and wheat traits

Abstract

AbstractSelecting more water‐efficient wheat (Triticum aestivum L.) varieties that are suited to no seasonal irrigation is an important way to improve water use efficiency (WUE) in the North China Plain (NCP). The goal of this study was to assess the yield and WUE of wheat, maize (Zea mays L.), and rotation, and to determine the traits of high‐WUE wheat varieties and clarify the mechanism for increasing WUE. Experiments were conducted during the 2012–2016 seasons using 10 common winter wheat varieties under no seasonal irrigation (W0) or two irrigation events (W2, irrigation at jointing and anthesis). No seasonal irrigation treatment decreased wheat and rotation yield, and improved maize yield and WUE of maize and rotation. No seasonal irrigation treatment decreased 150‐mm irrigation amount, reduced soil water content in 0–2‐m soil depth at wheat maturity and 1–2‐m depth after maize harvest, and extended the maize grain filling stage. Compared with the wheat genotype with the lowest WUE (‘Nongda 211’), under W0 condition, the genotype with the highest WUE, ‘Nongda 5133,’ could improve rotation yield and WUE by 10.7 and 10.9%, respectively. The WUE of wheat had a strong positive association with yield across the genotypes. High‐WUE varieties had a higher leaf area index at anthesis and higher late‐season photosynthesis rate and/or delayed canopy senescence under W0. This study indicated that W0 in wheat growing season could improve maize yield, narrow the rotation yield gap with W2 treatment, and improve wheat and rotation WUE by combining with high‐WUE wheat varieties.