Response of root traits to plastic film mulch and its effects on yield

Plastic film mulch (PM), a major rainwater harvesting measure, is now widely used to cope with drought in context of global climate change. However, the effects of PM on root traits are not clearly understood. Here, we summarized data from 36 independent field studies to examine the effect of PM to 9 root traits, and the relationships between root traits and yields. Averaged across all observation, PM had significant positive effects on root weight density (RWD), root length density (RLD), and root diameter (RD). The performance of root under PM in arid and semi-arid regions was much better than in semi-humid. PM had the greatest promoting effect on the root traits of gramineous crops represented by maize; PM could promote root growth and increase yield in clay soil better than in other soil textures. Changes in root distribution in the upper soil layer (0−40 cm) had a more important impact on the yield than that in the deep soil layer (below 40 cm); root traits that contribute most to yields in vegetative and reproductive growth stages were RWD and RD, respectively. The utilization of PM has important implications for future development of agriculture to benefit root growth and improve yield.