Augmenting the Stability of Soil Aggregate Carbon with Nutrient Management in Worldwide Croplands

Soil aggregates are the anticipated organic carbon repository, and the stability of aggregate is vital for the efficacy of carbon sequestration. The stability and carbon content of soil aggregates in croplands are affected by nutrient management; however, the changes of aggregate organic carbon stability (AOCS) remain elusive under nutrient management with nature-based solutions. A total of 2035 observations from 269 peer-reviewed articles was compiled to elucidate the changes of AOCS, including aggregate stability, physically protected organic carbon content (i.e., aggregate-associated carbon), and the decomposability of aggregate organic carbon under nutrient management with nature-based solution. The AOCS was significantly improved with nature-based nutrient addition (biochar, manure, straw, and soil conditioner) in contrast to merely synthetic fertilization. Aggregate stability and physically protected organic carbon increased by 18.8-23.3 % and 20.5-34.3 %, respectively, while the decomposability of aggregate organic carbon decreased. Furthermore, the changes of ACOS traits were strengthened with prolonged nutrient management with nature-based solution. Notably, AOCS decreased with the high levels of synthetic nitrogen, in which the contents of aggregate organic carbon and recalcitrant organic carbon were reduced. The findings indicate that nutrient management with nature-based solution can enhance AOCS, therefore, the viable nature-based nutrients are desirable for carbon sequestration in worldwide croplands.