Enhancing soil hydrothermal conditions and improving potato yields through furrow–ridge mulching under drought–prone semi–humid climatic conditions

In rainfed agricultural regions, furrow–ridge mulching plays a critical role in enhancing crop productivity. A two–year field experiment (2015: normal flow year; 2016: low flow year) was conducted in the arid farmlands of northwest China to evaluate the effects of four furrow–ridge mulching patterns on soil hydrothermal characteristics and potato yield. Full plastic film mulching on both ridges and furrows (PF+PF), half–film mulching—ridge mulching only (PF), plastic–mulched ridges combined with maize straw–mulched furrows (PF+MS), and non–mulched control (CK). Results showed furrow–ridge mulching patterns increased 0–200 cm soil water storage (SWS), especially during the critical growth stage of potato (70–90 DAS, days after sowing), with pronounced effects in 2016. PF+MS treatment regulated water consumption, reducing period evapotranspiration (ET p ) by 28.4 %, water consumption modulus (C p ) by 16.2 %, and water consumption intensity (C d ) by 28.5 %, while decreasing water consumption depth (W cd ) by 20 cm. Mulching raised soil temperature and effective accumulated temperature (≥ 10 ℃), with PF+PF treatment increasing average soil temperature by 1.7℃ (0–50 DAS) and PF+MS treatment showing dual effects (warming and cooling effects). Both PF+MS and PF+PF treatments significantly increased biomass (by 90.9 % and 90.2 %) and yield (by 50.4 % and 38.0 %) compared to the CK, while also improving the use efficiency of water and thermal resources. Grey correlation analysis identified water availability as the primary yield factor, soil moisture and temperature synchronously regulate potato yield formation. Thus, the plastic–mulched ridges combined with maize straw–mulched furrows (PF+MS) optimized soil hydrothermal conditions, significantly improving potato yield, water and heat resource use efficiency, and aiding sustainable dryland agriculture in the drought–prone semi–humid area of Loess Plateau with annual precipitation ranges between 369 mm and 463 mm. • Conducted four mulching patterns in rainfed agriculture across normal/low flow years, guiding tillage under varying rainfall. • Grey correlation analysis shows water availability is key yield factor, soil moisture and temperature co-regulate potato yield. • Dual mulching (plastic film on ridges, maize straw in furrows) significantly improved maize yields, water and heat use efficiency.