An analysis of soil carbon dynamics in long-term soil fertility trials in China

摘要: Soil carbon dynamics would be influenced by fertilization management in the agro-ecosystem. In this study, we analyze inputs and soil organic (SOC) under wheat-corn double cropping system based on four long-term experimental sites different climate zones of China. We examine responses to various using linear (S = aA − b) non-linear (\( S S_{M} \frac{A}{{A + K_{S} }} - S_{L} \)) equations. The term is SOC change rate; a, proportion C incorporated into soil; b, minimum rate SOC; SM, asymptotic maximum value at approaching infinity (Mg ha−1 year−1); SL, decomposition substrates, KS, a constant (or ‘half-saturation constant’). fitted equation with data over duration experiment. annual input (A) estimated measured crop biomass from manure. Different amounts balanced show little impact derived plants, reaching ~3.5 Mg year−1. much higher manure application than treatments chemical fertilizers only. Statistical analysis shows that equations perform equally well (p < 0.01) within interval. But more suitable for specific purpose. Using equation, can predict maintain current level 0.33–1.32 year−1 most but only 0.03 Changping site. nitrogen phosphate yield sufficient levels. However, increase 1 year−1, soils need 10 sites. Our results suggest increment stocks mainly related additional perspectives.