Effects Of Furrow-mulching Materials On Soil Temperature, Soil Moisture, Maize And Sorghum Production In Ridge-furrow Rainwater Harvesting

The shortage of precipitation resources, serious water loss and soil erosion, and the shallow of soil fertility layer are main limiting factors, which constrain agriculture and husbandry sustainable production in semi-arid Loess Plateau hilly regions. In order to improve soil moisture and temperature, and to increase rainwater resource utilization and to find the suitable furrow-mulching materials in ridge-furrow rainwater harvesting production, a field experiment in a randomized complete design was conducted to determine effects of different furrow mulching methods(no-mulching, liquid film mulching, straw mulching and biodegradable film mulching) on soil temperature, soil moisture, and silage yields, nutritional value, grain yields and water use efficiency(WUE) of maize and sorghum, with no-mulching as a control, at the Dingxi Agri-meteorological station. The results were followed.Average runoff efficiency(expressed as a ratio of runoff to rainfall received at the same period) was 74% for biodegradable mulch film, while analyzed by regression equation was 90%, threshold rainfall for the same treatment was 1.1 mm during maize and sorghum growing season in 2013.Compared with no-mulching, soil water storage in the 140 cm depth at the bottom of furrows increased 0.4, 21.5 and 8.6 mm for liquid film mulching, straw mulching and biodegradable film mulching during maize growing seasons, respectively, while increased 2.3 mm, 21.0 mm and 10.9 mm during sorghum growing seasons. The soil water storage during maize and sorghum growing seasons was in the order of no-mulching < liquid film mulching < biodegradable film mulching < straw mulching.Ridge mulching had distinct effects on topsoil temperature at furrow bottoms, but not at ridge tops during maize and sorghum growing seasons. Compared with no-mulching, topsoil(0-25 cm) temperature at furrow bottom profile increased 0.2 and 1.0℃, and mature date was early 3 and 7d for liquid film mulching and biodegradable film mulching during maize growing seasons, respectively, while topsoil temperature increased 0.2℃ and 1.1℃, and mature date was early 2 and 6 d during sorghum growing seasons. But topsoil temperature at furrow bottom profile decreased 1.1℃ and 1.3℃ for straw mulching during maize and sorghum production, respectively, while mature date was late 5 and 6 d.Compared with no-mulching, maize silage yield increased 0.4% and 10.4%, and its relative feeding value increased 7.2% and 8.7% for liquid film mulching and biodegradable film mulching, respectively, while sorghum silage yield increased 0.2% and 10.9%, and its relative feeding value increased 11.5% and 12.4%. But maize silage yield and its relative feeding value decreased 2.9% and 4.4%, respectively, for straw mulching, while sorghum silage yield decreased 0.7% and its relative feeding value increased 4.2%.Compared with no-mulching, maize grain yield increased 1.6% and 11.3%, and dry matter above ground increased 0.7% and 7.3% for liquid film mulching and biodegradable film mulching, respectively, while sorghum grain yield increased 1.1% and 11.8%, and dry matter above ground increased 1.6% and 9.4%. Maize grain yield and its dry matter above ground, and sorghum grain yield and its dry matter above ground decreased 2.2%, 1.9%, 1.1% and 1.0%, respectively, for straw mulching. Maize WUE increased 0.9, 0.5 and 4.9 kg hm?2 mm?1 for liquid film mulching, straw mulching and biodegradable film mulching, respectively, while sorghum WUE increased 0.3, 0.4 and 2.7 kg hm?2 mm?1.The average maize silage yield, dry matter above ground, grain yield, and WUE among different treatments were 1.7, 1.8, 2.1, and 1.9 times of sorghum. Maize was better than sorghum in ridge-furrow rainwater harvesting production.Biodegradable mulching film has similar effects on soil water conservation and temperature increasing as common plastic mulching film during early crops growing stages(emerging-jointing). And Biodegradable mulching film can be degraded in natural conditions during late crops growing stages(jointing-mature), and is a suitable mulching material in ridge-furrow rainwater harvesting production.