Can ridge-furrow with film and straw mulching improve wheat-maize system productivity and maintain soil fertility on the Loess Plateau of China?

Abstract

Ridge-furrow mulching patterns are beneficial to improve crop yields and rainwater use efficiency, but it is not clear whether they can improve productivity and simultaneously maintain soil fertility on the Loess Plateau of China. A three-year (2013–2016) field trial was conducted during the rotation of wheat (Triticum aestivum L.) – maize (Zea mays L.) to investigate the effects of ridge-furrow mulching patterns on soil moisture, soil fertility, grain yield, and water use efficiency (WUE). Four ridge-furrow planting patterns included: (1) white plastic film mulch over the ridge (RW), (2) straw mulch over the furrow (RS), (3) white plastic film mulch over the ridge and straw mulch over the furrow (RWS), and (4) black plastic film mulch over the ridge and straw mulch over the furrow (RBS). Flat planting without mulch was CK. The results showed that RW, RS, RWS, and RBS significantly improved soil water storage and aboveground biomass throughout each winter wheat and summer maize growing season compared with CK. Finally, winter wheat grain yield and WUE in the four mulching treatments markedly increased by 13.0–32.9% and 22.5–41.5% in a wet and cool season, 15.5–35.2% and 19.3–41.9% in a season with normal rainfall and temperatures, and 27.2–58.9% and 15.3–33.4% in a dry and warm season, respectively. Maize grain yield and WUE increased by 12.8–35.0% and 19.5–46.2% in a season with normal rainfall and temperature, 15.0–38.5% and 18.0–39.9% in a dry and cool season, and 17.4–50.5% and 13.0–42.5% in a dry and warm season, respectively. Among the four mulching treatments, RWS and RBS significantly improved the yield and WUE of wheat and maize relative to RW and RS over the three years. After three years, soil total nitrogen content in RWS and RBS was significantly greater than in RS. Besides, soil microbial biomass carbon and nitrogen, and soil dissolved organic carbon and nitrogen contents in RWS and RBS were all markedly higher than in RW and RS. Our results indicated that RWS and RBS were a promising agricultural practice that improved crop production and simultaneously maintained soil fertility in a rain-fed semi-arid region of China.