Factors affecting the net ecosystem productivity of agroecosystems on mineral soils: a meta-analysis

To optimize agricultural land management for soil carbon sequestration, it is necessary to identify whether agroecosystems are accumulating or gaining carbon. This can be done by determining an agroecosystem’s net ecosystem productivity (NEP). This study collated data from 40 papers, containing 242 annual measurements of NEP, to assess the impact of climate, soil type and management on the annual NEP of croplands and managed grasslands. Croplands lost significantly more carbon (110 g Cm−2) than managed grasslands (29.9 g Cm−2) and there was little statistical influence of climate, soil, or management practice on annual NEP. For agroecosystems to sequester carbon, there should be a shift in focus toward implementing management practices that increase carbon retention within agroecosystems.