Soil nutrients increase long‐term soil carbon gains threefold on retired farmland

Abstract Abandoned agricultural lands often accumulate soil carbon (C) following depletion of C by cultivation. The potential for this recovery to provide significant storage benefits depends on the rate accumulation, which, in turn, may depend nutrient supply rates. We tracked almost four decades intensive disturbance along an experimentally imposed gradient nitrogen (N) added annually combination with other macro‐ and micro‐nutrients. Soil %C accumulated over course study unfertilized control plots leading a gain 6.1 Mg ha −1 top 20 cm soil. Nutrient addition increased accumulation 17.8 fertilized plots, nearly threefold increase plots. These results demonstrate that substantial increases successional grasslands abandonment occur decadal timescales, is high rates nutrients. In addition, continued under elevated supply, suggesting short‐term experiments underestimate effects nutrients accumulation.