Objectives From the perspective of soil greenhouse gas emission and carbon footprint, we studied the effects of monitored fertilization combined with different mulching methods on emission reduction and yield improvement to provide a reference for greening wheat production in drylands areas.

Methods A long-term fertilization and mulching experiment was conducted in Hongdong County, Shanxi Province, and the cropping system was winter wheat-summer fallow, with five treatments: no fertilizer control, farmer’s practice (FP), monitoring fertilization (MF), nitrogen reduction monitoring and control fertilization plus ridge film and furrow sowing (RF), nitrogen reduction monitoring and control fertilization plus flat film and hole sowing (FH). During the two wheat seasons in 2018−2020, wheat yield and economic benefits were investigated, and the life cycle approach was used to estimate the greenhouse gas (GHG) emissions, greenhouse gas warming potential and greenhouse gas emission intensity of wheat field soils, and to calculate the carbon footprint of wheat field soils.

Results Compared to the FP treatment, the MF treatment achieved a 32.6% reduction in nitrogen fertilizer application while maintaining comparable wheat yields, along with significantly lowering GHG emissions by 24.0%. In contrast, the RF and FH treatments led to a significant increase in total GHG emissions by 12.0% and 44.6%, respectively. The production, transportation and application of nitrogen fertilizer contributed 20.3%−57.9% of total GHG emissions across treatments. Notably, plastic film usage under RF and FH treatments emerged as the second major emission source, accounting for 40.6% and 56.5% of total GHG emissions, respectively. Compared with FP, the MF treatment also significantly reduced the carbon footprint by 16.2%, while the RF and FH treatments had no significant effect on the carbon footprint; the MF, RF and FH treatments all significantly reduced the greenhouse gas emission intensity by 38.5%, 53.1% and 63.6%, respectively. Compared with MF, RF and FH treatments significantly increased wheat grain yield by 33.2% and 69.7%, grain income by 33.2% and 69.7%, and net income by 59.4% and 135.8%, respectively, and the yield and income of FH treatment were also significantly higher than that of RF treatment. In addition, RF and FH treatments significantly reduced greenhouse gas emission intensity by 32.0% and 49.2%, respectively.

Conclusions Film mulching on the basis of monitoring fertilization increased wheat grain yield and economic efficiency significantly. Nitrogen reduction monitoring and control fertilization plus flat film and hole sowing, owing to high land utilization efficiency, demonstrated even more remarkable yield and income benefits. Moreover, compared to nitrogen reduction monitoring and control fertilization plus ridge film and furrow sowing, it did not significantly raise the carbon footprint, and its greenhouse gas emission intensity was significantly lower than that of monitored fertilization without film mulching. Therefore, nitrogen reduction monitoring and control fertilization plus flat film and hole sowing is a optimal measure to achieve green, high and stable crop production in dryland regions.