Suitable furrow mulching material for maize and sorghum production with ridge-furrow rainwater harvesting in semiarid regions of China

In order to select environmentally friendly mulching materials and to increase rainwater utilization in a semiarid region of Northwest China, a field experiment was conducted using a randomized complete design to determine effects of three furrow-mulching materials (liquid film (LF), maize straw (MS) and biodegradable film (BF)) on soil temperature, moisture, evapotranspiration (ET), crop (maize and sorghum) yields and water use efficiency (WUE) with no-mulching (NM) as a control, during three consecutive crop growing seasons in years 2013-2015. Silage, grain, and biomass yields and WUE for maize were 1.75, 1.87, 1.82 and 1.76 times greater than corresponding yields and WUE for sorghum during the study period. BF increased topsoil temperature and soil water storage, while MS decreased topsoil temperature but increased soil water storage. Compared with NM, the increase in average topsoil temperature at the furrow bottoms of BF was 1.05-1.37 degrees C during the growing seasons for maize, while it was 1.07-1.25 degrees C during the growing seasons for sorghum. During the growing seasons, the decrease in topsoil temperature at the furrow bottoms for MS was 1.22-1.81 degrees C for maize, while it was 1.34-1.59 degrees C for sorghum. BF and MS decreased furrow soil evaporation but increased crop transpiration, while they did not shift the total water loss from ET. BF resulted in high soil temperature and moisture, increased crop yields, and WUE. Although low temperatures impaired emergence and crop development, high soil moisture increased crop yields and WUE with MS. Compared with NM, BF treatments resulted in increased mean silage, mean grain and mean biomass yields for maize of 17.0%, 17.7% and 13.7%, respectively, while corresponding yields for sorghum increased by 12.9%, 17.0% and 11.7%, respectively. The mean silage, grain, and biomass yields for maize with MS increased by 9.3%, 12.1% and 8.0 %, respectively, while corresponding yields for sorghum increased by 5.6%, 14.3% and 6.7%, respectively. Mean WUEs for maize and sorghum with BF significantly increased by 4.8 and 2.6 kg ha(-1)mm(-1), respectively, while those values with MS significantly increased by 3.8 and 2.8 kg ha(-1)mm(-1). MS provided a lower increase (12.1 %-14.3 %) in grain yields compared with BF (17.0 %-17.7%) in the study. LF had similar soil temperature and water moisture as with no mulching, and did not significantly increase either crop yields or WUE.