Marginal cost to increase soil organic carbon using no-till on US cropland

摘要

Recent global agreements on greenhouse gas emission reductions have reinforced the need to develop cost-effective offset programs that can be implemented to help augment emission reductions. One approach to offset carbon dioxide (CO2) emissions may be to increase soil organic carbon (SOC) stocks by reducing soil disturbance by changing from conventional tillage (CT) to no tillage (NT). In this analysis, the cost to increase SOC sequestration achieved on cropland by changing from CT to NT is estimated. The marginal cost of increasing SOC is determined by the amount SOC can be increased and the difference in profit of changing from conventional to no-till. Landowner costs and profit are derived from crop enterprise budgets, county yield data, and regional crop prices. A risk factor is also used to increase the cost of no-till adoption to account for the apparent reluctance of landowners to adopt no-till. The SOC sequestration potential on corn (Zea mays) and soybean (Glycine max) cropland combined is about 49.1TgCO(2)year(-1) (1Tg=10(12)g) of which 47.6TgCO(2)year(-1) (nearly 97%) could be attained for less than $20-Mg-1 CO2 (1Mg=10(6)g). When the risk factor is included in the assessment, over 19.7TgCO(2)year(-1) could be attained for less than $20-Mg-1 CO2. The analysis demonstrates that SOC sequestration through changes from CT to NT on corn and soybean land could economically offset a portion of CO2 emissions.