Optimizing straw strip-mulching to enhance winter wheat productivity in semi-arid drylands

Straw strip-mulching can improve soil water efficiency but the effects of mulching patterns has not been determined for dryland winter wheat (Triticum aestivum L.) production. The conventional practice of sowing with no mulch (CK) was compared in the four cropping seasons from 2015 to 2019 with four straw strip-mulching patterns (SSM3, SSM4, SSM5 and SSM6 corresponding to 59, 50, 42, and 37 % of the land covered by strips) to evaluate their effects on soil water and yields. Evapotranspiration (ET) was 19.4 and 12.5 mm more with SSM3 and SSM4, respectively, compared with CK on average during the high water use growth stage of jointing to blooming. Specifically, evapotranspiration under straw strip-mulching treatments showed an inverse relationship with mulching percentage, following the order: SSM6 > SSM5 > SSM4 > SSM3. During the winter wheat growth period, SSM3 had more SWC and 11.4 mm less ET compared with CK. The SSM3 treatment compared with CK had 3.6 and 2.2 kg ha⁻¹ mm⁻¹ for biomass- and yield-based water use efficiency, respectively, compared with the mean WUE of 25.2 kg ha⁻¹ mm⁻¹ and 9.9 kg ha⁻¹ mm⁻¹ . Although SSM3 increased the grain yield by about 7.0 % in relatively wet years, SSM3 had a great potential to increase production in dry years, which showed that yield components and yields were more with SSM3 compared with CK including 11.8 % more spike m⁻², 29.7 % more kernel spike⁻¹, 22.5 % more biomass yield, and 26.9 % more grain yield. Overall, SSM3 compared with SSM4, SSM5, SSM6, and CK had higher water use efficiency and yield. Optimized straw strip-mulching patterns enhance sustainable wheat yields by improving water use efficiency on China's Loess Plateau.