Objectives From the perspective of soil greenhouse gas emission and carbon footprint, we studied the emission reduction and yield increase effects of monitoring and applying fertilizer technology together with different mulching methods to provide reference for greening wheat production in drylands.

Methods The long-term positioning experiment of fertilization and mulching was located in Hongdong County, Shanxi Province, and the cropping system was winter wheat-summer leisure, with five treatments: no fertilizer control, farmer’s practice (FP), monitoring fertilization (MF), lodge-tillage and film-mulching (RF), film-mulching and hole-sowing (FH). For 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 carbon 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 carbon 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 carbon emission intensity by 32.0% and 49.2%, respectively.

Conclusions Film mulching on the basis of monitoring fertilization further increased wheat grain yield and economic efficiency significantly. Flat-film hole sowing, owing to high land utilization efficiency, demonstrated even more remarkable yield and income benefits. Moreover, compared to ridge tillage, it did not significantly raise the carbon footprint, and its carbon emission intensity was significantly lower than that of monitored fertilization without film mulching. Therefore, flat film hole sowing is a the optimal measure to achieve green, high and stable crop yields in the region.