Straw strip mulching affects soil moisture and temperature for potato yield in semiarid regions

Straw mulching is widely used in agriculture to conserve soil water and improve crop productivity. The effects of straw strip mulching and film mulching on dryland soil water storage and temperature, potato (Solanum tuberosum L.) growth and yield, and water use efficiency (WUE) were examined from 2014 to 2015 in the rainfed semi-arid regions of China. Field experiments were conducted with four treatments: (a) alternating strips mulched with maize (Zea mays L.) straw and bare plots with no ridges (SM); (b) alternating large ridges and small furrows with only the ridges mulched with black polyethylene film (PMP); (c) alternating narrows and wide ridges both mulched by black polyethylene film (PMF), and (d) traditional bare land planting without mulching (CK). The results indicated that film mulching had positive effects on soil water storage at the early stage of potato growth, while the SM significantly improved soil water storage at the late growth stage. Soil water storage (0-2-m depth) was 11.3-35.4 mm greater with the SM than that with the other treatments, especially during the tuber bulking in summer drought period. Compared with the CK, the SM significantly decreased soil temperature by 0.8-1.4 degrees C, and increased potato yield by 10.5-34.2%, WUE by 8.9-29.8%, and commodity rate by 14.7-38.8%. Compared with the PMP and PMF, the SM increased potato yield by 4.6-12.9 and 3.4-9.3%, respectively. This might be contributed to increased soil moisture and lower soil temperature, which promoted potato growth, yield, and commodity rates.