Effects of conservation tillage with straw mulching on annual yield and water utilization in a winter wheat-summer maize cropping system on the North China Plain

Understanding the combination of conservation tillage and straw mulching on water utilization is important for developing water management strategies in arid and semiarid areas. Few studies have investigated the effects of different tillage treatments on precipitation efficiency in winter wheat (Triticum aestivum L.)-summer maize (Zea mays L.) cropping systems. A 3-year field experiment with five treatments, that is, conventional tillage (CT), no-tillage, no-tillage with straw mulching (NT + S), subsoiling tillage, and subsoiling tillage with straw mulching (ST + S), was conducted. The objective was to investigate how conservation tillage with straw mulching affected soil water storage (SWC), precipitation storage efficiency (PSE), water consumption, grain yield, water use efficiency (WUE), and precipitation use efficiency (PUE) in a winter wheat-summer maize cropping system. The results indicated that the ST + S treatment increased SWC by 10.1% and 8.3% in 2014-2015 and 2015-2016, respectively. The average PSE over the 3 years under the ST + S treatment was significantly higher, by 9.1% and 6.6%, than that under the CT treatment during the respective wheat and maize seasons. Compared with CT, the average annual yield under the NT + S treatment and ST + S treatment increased by 8.5% and 14.4%, respectively. In the winter wheat-summer maize system, the NT + S and ST + S treatments significantly increased the annual WUE and PUE. The annual average PUE under the ST + S treatment was significantly higher, by 14.1%, than that under CT over the 3 years. Therefore, the ST + S treatment was more beneficial than the other treatments for increasing yield, WUE and PUE in sandy loam soil on the North China Plain. Conservation tillage with straw mulching treatments improved the average annual yield by 8.5%-14.4%.Subsoiling tillage with straw mulching (ST + S) increased precipitation storage efficiency during the crop growth seasons.ST + S performed better in terms of the precipitation use efficiency and water use efficiency on the North China Plain.