Straw strip mulching in a semiarid rainfed agroecosystem achieves winter wheat yields similar to those of full plastic mulching by optimizing the soil hydrothermal regime

Abstract

Straw strip mulching (SM) is a new mulching technology. From 2012 to 2018, SM’s effects on soil moisture and temperature and production performances were compared with other mulching practices, using three treatments: full-cover plastic mulch (PM), no mulch with wheat sown in rows as the control (CK), and SM with 50% to 59% of the field area mulched. Compared with CK, on average over six growing seasons, SM and PM increased grain yield by 27.0% and 21.7%, straw yield by 21.6% and 22.6%, kernels ha−1 by 26.6% and 19.0%, net income by 29.8% and −25.0%, soil temperature at 5 cm by −1.5 °C and 0.2 °C from overwintering to maturity, and soil water storage at 0–200 cm by 25 and 22 mm, respectively. The increase in soil moisture in SM and PM was greater in the early period (overwintering to jointing) than in the later period (booting to maturity) and at 0 to 120 cm than at 120–200 cm in the early period. Although the mean evapotranspiration of whole growth period across six seasons was similar among treatments, SM and PM increased water consumption during the key formation period of yield components after overwintering by 16 and 32 mm, respectively, while reducing it before overwintering. Compared with CK, SM and PM had the effects of warming during overwintering and cooling after jointing. By increasing water consumption after overwintering and ratio of transpiration to evapotranspiration and providing favorable soil temperature for multiple growth stages and more sufficient soil moisture, SM and PM promoted vegetative growth and increased kernels ha−1, the main mechanisms by which SM and PM increased grain yield relative to CK. Relative to PM, SM is a more economically beneficial and environment-friendly technology for dryland wheat production.