Spatially explicit estimates of N2O emissions from croplands suggest climate mitigation opportunities from improved fertilizer management

摘要: With increasing nitrogen (N) application to croplands required support growing food demand, mitigating N2O emissions from agricultural soils is a global challenge. National greenhouse gas accounting typically estimates at the country scale by aggregating all crops, under assumption that are linearly related N application. However, field studies and meta-analyses indicate nonlinear relationship, in which relatively greater higher rates. Here we apply super-linear response model crop-specific, spatially-explicit synthetic fertilizer manure inputs provide subnational of croplands. We estimate 0.66 Tg N2O-N direct circa 2000, with 50% concentrated 13% harvested area. Compared IPCC Tier 1 linear model, our updated range 20-40% lower throughout Sub-Saharan Africa Eastern Europe, >120% some Western European countries. At low rates, weak non-linear suggests large increases would generate small emissions. Since aggregated data underestimation bias models, high-resolution critical accurate estimates.