Characteristics of Cropland Topsoil Organic Carbon Dynamics Under Different Conservation Tillage Treatments Based on Long-term Agro-ecosystem Experiments Across Mainland China
Conservation tillage(CT)has become one of the most important measures of sustainable agriculture development,and it is a relatively new concept but widely adopted in China and has considerable benefits.In this paper data of topsoil soil organic carbon(SOC)in longterm field experiments of China from publications available from 1979 to 2008 was collected to summarize and analyze the dynamics of SOC.The data set comprised of 88 observations(51 and 37 from dry cmplands and rice paddies,respectively)of SOC under different conservation tillage measures at 59 experiment sites(31 for dry croplands and 28 for rice paddies)across 1 8 provinces of mainland China.The soils represented by the experiments covered 12 dominant types of cropland soils from China.The relative increase in SOC content was analyzed with respect to initial SOC stock,and rice paddies and dry croplands soils were compared.This analysis was done for 2 different categories of long-term conservation tillage:no-tillage(reduced tillage)and straw mulching.An overall increase in SOC wns pmjcoted for both types ofcroplands,with a relative annual increment(RAI,g·kg~(-1)·a~(-1))of-0.30～0.75(0.21 on average)fordry croplandsoils,and-0.20～2.71(0.51 on average)for rice paddy soils.Initial andfinal SOC valuesin rice paddies were higher significantly than that in dry croplands.and rice paddies can enhance SOC accumulation than dry croplands.Enhanced SOC accumulation wag much higher under straw mulching than that in no-tillage and reduced tillage.Comprehensive conservation tillage(no-tillage with straw mulching)contained carbon sequestration durations of 27 and 23 years for rice paddies and dry croplands,respectively.Conservation tillage is a key technique of sustainable agriculture,and carrying out research of application and extension of conservation tillage in China is of profound significance.It is necessary to strengthen the study for improving crop productivity,enhancing SOC accumulation and change the traditional idea of farmers so as to accelerate the application of conservation tillage in China.
国家科技期刊平台
NSTL
万方数据
维普
