Mulching materials improve soil properties and maize growth in the Northwestern Loess Plateau, China

Water deficiency is the main limiting factor for crop growth in rain-fed areas. Mulching can affect the soil microclimate (soil water and temperature) and influence the grain yield of crops. A field experiment was conducted to determine the effect of different mulching materials on soil temperature, soil water, crop growth and yield, and water use efficiency (WUE) in spring maize (Zea mays L.) between 2009 and 2011 in Heyang County, Shaanxi, China. The field experiment used five mulch treatments: polyethylene film (PM), biodegradable polymer film (BM), maize straw (MM), liquid membrane (LM), and an uncovered control (CK). In the early stage of maize growth, the topsoil temperatures (0-10 cm) in the PM and BM treatments were significantly (P < 0.05) higher than CK, whereas the soil temperature in the MM treatment was significantly (P < 0.05) lower than CK. The PM, BM, and MM treatments also significantly increased soil water during the early growth stage. However, soil water (0-200 cm) in the PM and BM treatments was lower than in the CK treatment during the middle and later growth stages. There was no significant difference (P > 0.05) in soil temperature or soil water in the LM treatment during the entire growing season. Maize yield increased significantly (P < 0.05) in both the PM and BM treatments by 26.1% and 27.5% during the experimental period compared to the CK treatment. Water use efficiency also significantly increased in these two treatments by 25.1% and 27.6%. These results show that both PM and BM had significant effects on soil temperature, water conservation and maize yield, but no significant (P > 0.05) differences were observed between these two treatments. Biodegradable polymer film is useful in reducing environmental pollution caused by polyethylene film and could potentially replace polyethylene film during agricultural production in the Northwestern Loess Plateau, China.