耕作方式对潮土有机碳及碳库管理指数的影响

Effects of Different Tillage Modes on Soil Organic Carbon and Carbon Pool Management Index in Fluvo-aquic Soils

为了探明华北潮土区农田耕作方式对土壤有机碳库及碳库管理指数的影响,应用田间试验,研究撂荒、翻耕、免耕和旋耕4种方式下,耕层(0～20 cm)土壤总有机碳和不同态活性有机碳含量的变化,对比分析不同耕作方式对土壤碳库管理指数的影响。结果表明:免耕和旋耕均有利于土壤有机碳累积,与撂荒相比,免耕和旋耕处理土壤总有机碳含量分别增加26.42%和12.52%;土壤活性有机碳对不同耕作措施的响应不同,与撂荒相比,翻耕、免耕和旋耕处理,土壤易氧化有机碳含量分别提高23.72%,44.34%和27.84%,水溶性有机碳含量分别降低了24.11%,24.56%和43.89%。土壤微生物量碳含量仅在免耕方式下提高了109%,其他耕作方式下没有显著变化;免耕、旋耕和翻耕处理下,土壤碳库活度、碳库指数均显著增加,碳库管理指数分别比撂荒处理提高47.82%,27.18%和30.47%,可见耕作对优化土壤碳库管理具有显著促进作用。

Applied field trials, four tillage patterns including abandoned, tilled, no-tillage and rotary were designed to study the effects of different tillage modes on soil organic carbon and carbon management index （CMI） in North China Plain. The change in the SOC contents and different form labile organic carbon in these four different tillage modes were studied. Then contrastive analyzed the effect of different tillage modes on carbon management index. The results showed that, no-tillage and rotary were both beneficial to the accumulation of SOC. Compared with abandoned, total organic carbon under no-tillage and rotary respectively increased 26.42% and 12.52%. The active organic carbon responded to different tillage modes in different ways. Compared with abandoned, when took the mode of tilled, no-tillage and rotary, easily oxidized organic carbon respectively increased 23.72%, 44.34%, 27.84%, water oxidized organic carbon respectively increased 24.11%, 24.56%, 43.89%. Soil microbial biomass increased 109% under no-tillage. There were no significant change under other tillage modes, soil cultivation had promotion effect to optimize carbon management index,the mode of tilled, no-tillage and rotary had respective increased at 47.82%, 27.18% and 30.47%. It conclnded that different tillage modes had significant effect on organic carbon library activities in fluvo-aquic soils.