Introduction:To generate information for the effective management of soil organic carbon(SOC)sequestration in Chinese croplands,we compared the additional organic carbon(C)that can be stabilized by fine soil particles...Introduction:To generate information for the effective management of soil organic carbon(SOC)sequestration in Chinese croplands,we compared the additional organic carbon(C)that can be stabilized by fine soil particles(<20μm)with typical fertilization practices across soil types and climate zones.Using data from 30 long-term experimental study sites across the major agricultural zones in China,we estimated stable SOC saturation deficit(SOC_(deficit))under no fertilization(CK),chemical fertilization(CF),straw plus CF(S+CF),and manure plus CF(M+CF).Stable SOC_(deficit)was defined as the difference between potential and current SOC stabilized by fine soil particles.Outcomes:Stable SOC_(deficit)values varied from 51%to 82%.Soils dominated by 2:1 clay minerals showed larger stable SOC_(deficit)than soils dominated by 1:1 clay minerals under each treatment.For soils dominated by 2:1 clay minerals,stable SOC_(deficit)was significantly lower under M+CF(69%)than under CK,CF,and S+CF(78-82%)treatments,and it increased with increasing mean annual temperature(<10°C).In soils dominated by 1:1 clay minerals,stable SOC_(deficit)was considerably lower in paddy and paddy-upland than in upland soils,suggesting that paddies effectively stabilize C inputs.Discussion:Agricultural soils in China have considerable C sequestration potential,despite decades of fertilization practices.To manage soil C sequestration and model soil C dynamics effectively,factors such as soil mineral types,fertilization,and cropland use should be considered.Conclusion:Our results demonstrated that manure addition was the best fertilization method for improving soil fertility,whereas straw return in Chinese croplands should take into account climate mitigation in future.展开更多
基金This work was supported by the National Natural Science Foundation of China[41501334 and 41571298].
文摘Introduction:To generate information for the effective management of soil organic carbon(SOC)sequestration in Chinese croplands,we compared the additional organic carbon(C)that can be stabilized by fine soil particles(<20μm)with typical fertilization practices across soil types and climate zones.Using data from 30 long-term experimental study sites across the major agricultural zones in China,we estimated stable SOC saturation deficit(SOC_(deficit))under no fertilization(CK),chemical fertilization(CF),straw plus CF(S+CF),and manure plus CF(M+CF).Stable SOC_(deficit)was defined as the difference between potential and current SOC stabilized by fine soil particles.Outcomes:Stable SOC_(deficit)values varied from 51%to 82%.Soils dominated by 2:1 clay minerals showed larger stable SOC_(deficit)than soils dominated by 1:1 clay minerals under each treatment.For soils dominated by 2:1 clay minerals,stable SOC_(deficit)was significantly lower under M+CF(69%)than under CK,CF,and S+CF(78-82%)treatments,and it increased with increasing mean annual temperature(<10°C).In soils dominated by 1:1 clay minerals,stable SOC_(deficit)was considerably lower in paddy and paddy-upland than in upland soils,suggesting that paddies effectively stabilize C inputs.Discussion:Agricultural soils in China have considerable C sequestration potential,despite decades of fertilization practices.To manage soil C sequestration and model soil C dynamics effectively,factors such as soil mineral types,fertilization,and cropland use should be considered.Conclusion:Our results demonstrated that manure addition was the best fertilization method for improving soil fertility,whereas straw return in Chinese croplands should take into account climate mitigation in future.
