Year-round plastic film mulch to increase wheat yield and economic returns while reducing environmental risk in dryland of the Loess Plateau

In the coming decades, humanity will face great challenges in ensuring food and environmental security while reducing poverty through increasing economic profits. Plastic film mulch is an effective management practice for ensuring food security by improving crop productivity per unit area. However, its effects on environmental and economic benefits have not been well evaluated. Here, a location-fixed field experiment was performed to determine the effect of year-round plastic film mulch (YPM, mulching soil surface with plastic film during the growing season and fallow season of winter wheat) on wheat yield, environment (nitrate-N leaching and greenhouse gas (GHG) emissions), and economic returns. Compared with farmer practice (the local traditional practice), adoption of YPM increased the mean yield by 11%, which is attributed to the fact that YPM increased soil water storage at wheat sowing and soil temperature during wheat growing season by a mean of 7% and 0.6 °C, respectively. The increased grains induced a 12% increase in net economic returns. The YPM decreased the soil nitrate-N leaching by 51%, which was explained by decreasing soil nitrate-N residue caused by the increased yield. The YPM also reduced GHG emissions intensity by an average of 12%. As a result, YPM was a better choice for increasing yield and economic returns while reducing environmental risk. In the future, we should develop better mulching systems to further improve food, environmental benefits, and economic returns in dryland farming production.