Optimizing nitrogen fertilization rate to enhance soil carbon storage and decrease nitrogen pollution in paddy ecosystems with simultaneous straw incorporation

Abstract

Nitrogen fertilization (NF) is an important agricultural management practice that greatly affects soil carbon (C) storage through regulating the balance of soil C input (straw biomass) and output (ecosystem respiration), especially for agroecosystems with simultaneous straw incorporation (SI). However, little is known about how different NF rates affect soil C balance (net ecosystem carbon budget, NECB) in flooded paddy ecosystems with SI. We conducted a two-year field experiment in a typical rice–wheat cropping system in southern China to investigate the response of soil C input (net primary production (NPP) and SI), output (ecosystem respiration and methane emissions), and NECB and N losse..