Effects of 12-year cropping systems and tillage practices on crop yield and carbon trade-off in dryland Loess Plateau

Context

Cropping systems and tillage practices suitable for local environmental conditions to balance the demand for food production and environmental impacts are critical for achieving a low-carbon cycle and sustainability of agricultural production systems in arid and semiarid regions.

Objectives

This study aimed to evaluate the effect of three tillage practices under diversified cropping systems in terms of food production, farmers’ income, mitigation of greenhouse gas (GHG) emissions, and economic and environmental sustainability.

Methods

Therefore, we conducted a 12-year (2007–2019) field experiment involving three tillage practices (no-tillage, NT; subsoiling tillage, ST; conventional tillage, CT) and three cropping systems (continuous winter wheat, W-W; winter wheat-spring maize cropping, W-M; continuous spring maize, M-M) in the Loess Plateau of China to evaluate their impact on food production, farmers’ income, GHG emissions, and environmental sustainability.

Results

Results indicated that the equivalent yield and equivalent economic benefit were the highest for M-M (9412 kg ha⁻¹and 2655 USD ha⁻¹); W-M and M-M increased equivalent yield by 44.1 % and 102.4 %, equivalent economic benefit by 44.6 % and 164.6 %, soil C sequestration by 23.8 % and 52.9 %, and reduced net GHG emissions (NGHG) by 12.5 % and 7.3 %, respectively, compared with W-W. The equivalent yield and equivalent economic benefit were highest under ST (7200 kg ha⁻¹ and 1767 USD ha⁻¹); NT and ST increased equivalent yield by 3.7 % and 8.1 %, equivalent economic benefit by 10.2 % and 11.1 %, soil C sequestration by 23.5 % and 7.5 %, and carbon sustainability index (CSI) by 5.5 % and 3.1 %, respectively, compared with CT. In addition, NT resulted in 6.5 % lower NGHG emissions than CT, whereas ST resulted in 2.7 % higher NGHG emissions than CT. This study identified W-M and NT with a higher comprehensive evaluation index (CEI) based on entropy-TOPSIS considering 6 indicators (equivalent yield, equivalent economic benefit, soil C sequestration, carbon sustainability index, net greenhouse gases emissions and yield-scaled carbon footprint).

Conclusion

The adoption of W-M and NT in the Loess Plateau has the potential to enhance crop yield and farmers’ income while proving benefits to the environment.

Implications or significance

These findings provide a scientifically grounded basis for selecting effective agricultural management strategies that can maintain food security while minimizing environmental impacts amid climate warming.