Effects of furrow-mulching materials on soil temperature, crop yield and water use efficiency in ridge-furrow rainwater harvesting systems

To find suitable environmental protection mulching materials of crop cultivation, improve soil temperature and soil moisture, and to increase rainwater resource utilization in semiarid regions in Northwest China, a randomized complete design field experiment was conducted. The experiment determined the effects of different furrow mulching methods (no-mulching, liquid film mulching, straw mulching, biodegradable film mulching, and no mulching as the control) on soil temperature, soil moisture, crop yield (maize and sorghum) and water use efficiency (WUE) in western hilly region of the Loess Plateau. The results showed that compared with no mulching, top soil (025 cm) temperature at furrow bottom profile increased by 0.2 ℃ and 1.0 ℃, respectively, for liquid film mulching and biodegradable film mulching during maize growing season, and by 0.2 ℃ and 1.1 ℃ during sorghum growing season. It also decreased by 1.1 ℃ and 1.3 ℃ for straw mulching during maize and sorghum growing seasons, respectively. Soil water storage increased by 0.4 mm, 21.5 mm and 8.6 mm for liquid film mulching, straw mulching and biodegradable film mulching during maize growing seasons, respectively. It also increased by 2.3 mm, 21.0 mm and 10.9 mm for the three mulching modes during sorghum growing season, respectively. Maize silage yield increased by 0.4% and 10.4% for liquid film mulching and biodegradable film mulching, respectively. Then maize grain yield increased by 1.6% and 11.3% and aboveground dry matter increased by 0.7% and 7.3% under the two mulching modes, respectively. Sorghum silage yield increased by 0.2% and 10.9% for liquid film mulching and biodegradable film mulching, respectively. Then sorghum grain yield increased by 1.1% and 11.8% and aboveground dry matter increased by 1.6% and 9.4% under the two mulching modes, respectively. Whereas, under straw mulching condition, the silage yield, grain yield and aboveground dry matter decreased, respectively, by 2.9%, 2.2% and 1.9% for maize planting, and decreased by 0.7%, 1.1% and 1.0% for sorghum planting, respectively, compared with those under no-mulching treatment. The WUE of maize increased by 0.9 kg.hm^-2.mm^-1, 0.5kg.hm^-2.mm^-1 and 4.9 kg.hm^-2.mm^-1, respectively, and sorghum WUE increased by 0.3 kg.hm^-2.mm^-1, 0.4kg.hm^-2.mm^-1 and 2.7 kg.hm^-2.mm^-1, respectively, under liquid film mulching, straw mulching and biodegradable film mulching modes, compared with those under the control. Based on the results of crop yield, WUE and environmental protection benefits, the biodegradable film was a suitable furrow mulching material in ridge-furrow rainwater harvesting systems in the semiarid Loess Plateau regions.