Response of soil water, temperature, and maize ( Zea may L.) production to different plastic film mulching patterns in semi-arid areas of northwest China

Plastic film mulching has been used widely to increase crop productivity in dryland farming. In this study, to identify the optimal mulching pattern and ensure the efficient utilization of soil water in the semi-arid areas of northwest China, we tested the following five treatments for 3 years (2013–2015): (1) full amount of plastic film with flat mulching (FL mulching) throughout the whole season (FLW), or (2) only during the growing season (FLG); (3) alternating ridges and furrows where only the ridges were mulched with plastic film (RF mulching) throughout the whole season (RFW), or (4) only during the growing season (RFG); (5) flat planting without mulching throughout the whole season (NM). The results showed that FLW was more beneficial for reducing soil water losses during the fallow season compared with RFW. FL mulching enhanced soil water consumption during the maize growing season, but promoted maize production compared with RF mulching due to the increased soil temperature. The rainfall was low during July–September in 2015, and the soil water storage at harvest under FLW and FLG were 9.13 mm higher and 8.01 mm lower than the stable soil water, respectively, thereby suggesting that FLW increased the soil water supply capacity in this drought year, and thus it was more sustainable in terms of soil water utilization compared with FLG. With FLW, the average yield increased by 838 kg ha−1, 1944 kg ha−1, 2363kg ha−1, and 5164 kg ha−1, compared with FLG, RFW, RFG, and NM, respectively, and the average net income increased by 244 USD ha−1, 520 USD ha−1, 643 USD ha−1, and 1166 USD ha−1. These results suggest that FLW was an effective method for substantially increasing economic benefits and maize yields in semi-arid areas.