Soil greenhouse gas emission and yield in wheat fields under different tillage patterns

Objectives The effects of different tillage patterns on soil greenhouse gas emission and yield in wheat fields were studied in order to provide a reference for achieving high carbon sequestration and yield.

Methods The Jimai 22 wheat variety was tested under four tillage treatments (perennial plowing tillage, P; perennial rotary tillage, R; perennial minimum and no tillage, S; and minimum and no tillage with a 2-year subsoiling interval, SS) during the wheat growing seasons of 2020 and 2021. Soil samples of 0–45 cm soil layers were collected in each to determine the content of soil aggregates with diameter >0.25 mm as well as the content of soil organic carbon and microbial biomass carbon across the tillage treatments. Greenhouse gas emission fluxes were measured using static closed chamber-gas chromatography. Grain yield and yield components were measured at maturity.

Results The content of soil aggregate with diameter >0.25 mm in the 0–15 cm soil layer under SS treatment was similar to that under S treatment, but higher than those in P and R treatments. The soil aggregate in 15–45 cm soil layer was significantly higher than those of other treatments. The content of soil organic carbon and microbial biomass carbon in the 0–45 cm soil layer treated with SS was the highest. In the wheat growing season, the global warming potential of greenhouse gases under SS treatment increased by 7.9%, compared with S treatment, and decreased by 12.2% and 7.3% compared with P and R treatments, respectively. Compared with P, R, and S treatments, the greenhouse gas emission intensity of SS treatment decreased by 28.6%, 28.6%, and 16.7%, respectively. At maturity, the 1000-kernel weight under SS treatment increased by 4.7%, 8.7%, and 9.6%, compared with P, R, and S treatments, while the grain yield of SS treatment increased by 7.1%, 14.2%, and 19.4%, respectively.

Conclusions SS treatment increased the content of aggregates with diameter >0.25 mm in the 0–45 cm soil layer, as well as the content of soil organic carbon and microbial biomass carbon, reduced the intensity of greenhouse gas emissions and promoted higher yield. To sum up, the SS pattern is the best tillage treatment for better yield and environmental benefits.