Partial-film mulch returns the same gains in yield and water use efficiency as full-mulch with reduced cost and lower pollution: A meta-analysis.

BACKGROUND Plastic film mulch is widely used to improve crop yield and water use efficiency (WUE, yield per unit evapotranspiration) in the semi-arid regions. It is commonly applied as partial-film mulch (PM: at least 50% soil cover) or full-film mulch (FM: complete soil cover). The PM has lower economic and environmental cost; hence it would be a superior technology provided it delivers similar gains in yield and water use efficiency in relation to FM. RESULTS To solve contradictory results from individual studies, we compared FM and PM in a meta-analysis of 100 studies with 1881 comparisons (685 for wheat; 1196 for maize). Compared with bare ground, FM and PM both increased yield of wheat (20-26%) and maize (37-52%), and WUE of wheat (16-20%) and maize (38-48%), with statistically undistinguishable differences between PM and FM. The increases in crop yield and WUE were stronger at elevation >1000 m, with annual precipitation<400 mm, and on loess soil, especially for maize. CONCLUSIONS We concluded that partial-film mulch could replace full-film mulch to return similar yield and WUE improvement, with reduced cost and environmental pollution. This article is protected by copyright. All rights reserved.