Effects of rainfall harvesting and mulching technologies on soil water, temperature, and maize yield in Loess Plateau region of China

Precipitation is the major factor limiting crop growth in the semi-arid Loess Plateau region of China. Ridge-and-furrow rainfall harvesting systems (RFRHS) with mulches are used to increase water availability to crops, thereby improving and stabilising agricultural production in the semi-arid region of China. We conducted a field experiment from 2007 to 2010 in the Weibei Highlands of China, to determine the influence of RFRHS with different mulching patterns on soil water content, temperature, water-use efficiency, and maize yield (Zea mays L.). Ridges were covered with standard plastic film in all RFRHS treatments, while different furrow treatments were mulched with standard plastic film (PP), biodegradable film (PB), maize straw (PS), or liquid film (PL), or left uncovered (P). A conventional flat treatment without mulching was used as the control. In the early stage of maize growth, the topsoil temperature (5–20cm) under PP and PB was significantly (P<0.05) higher than under the control, whereas the soil temperature under PS was significantly (P<0.05) lower than under the control. Treatments PP, PB, and PS also significantly improved soil water content during early growth stages. There was no significant difference in soil water content between PS and the control during middle and late growth stages. However, the soil water content in the deep soil layers with PP and PB was less than that of the control. Soil temperature and soil water content of PL and P were slightly higher than the control during the whole growing season. Higher maize yield and water-use efficiency was found with PP, PB, and PS. Compared with the control, the 4-year average maize yield with PP, PB, and PS was significantly (P<0.05) increased, by 35, 35, and 34%, while the average water-use efficiency increased by 30, 31, and 29%, respectively. Net income was highest with PS, followed by PB, where the 4-year average net income increased by 2779 and 2752 Chinese yuan (CNY) ha-1, respectively, compared with the control. Soil water and temperature conditions were improved, while the maize yield and net income were increased, when ridges were covered with standard plastic film and the furrows were mulched with either biodegradable film or straw. Therefore, these two treatments are considered most efficient for maize production in the drought-prone, semi-humid region of the Loess Plateau, China.