Wei Gong Xiaoyuan Yan Jingyan Wang. The effect of chemical fertilizer application on carbon input and export in soil—A pot experiment with wheat using natural 13C abundance method. Geoderma 2012 189–190: 170–175.

Abstract

The enhancement of soil organic carbon (SOC) is important for sustainable agriculture while changes in SOC depend on the balance between carbon (C) input and export. To investigate how chemical fertilizers contribute to C input (e.g. plant-derived C) and export (e.g. original SOC decomposition) in soil a wheat (a C3 plant) pot experiment was conducted using a Phaeozem that had previously been used to cultivate maize (a C4 plant). The natural 13C abundance method was used to quantify wheat-derived SOC (WSC) and microbial respiration using the original SOC (Rmicrobial) during the wheat growing season. The wheat grain WSC wheat-derived C (WDC: including WSC root and stubble biomass C) and Rmicrobial-derived CO2 emission (SCE) in fertilized treatments increased by 4.8–31.1% 48.9–122.4% 21.3–62.2% and 6.0–51.8% respectively when compared to unfertilized treatments. The total SOC in the post-experimental soil increased by 0.14–0.97% when compared to pre-experimental soil because theWSC input was larger than the SCE export and itwould be increased further if wheat root and stubble biomass C were included. Therefore application of chemical fertilizer not only directly increases crop yield but also indirectly contributes to C sequestration by favoring crop growth and crop-derived C input in soil.