长期不同施肥下我国4种典型土壤活性有机碳及碳库管理指数的变化特征

Characteristics of soil labile organic carbon and carbon management index under different long-term fertilization systems in four typical soils of China

研究长期不同施肥处理对3种旱作土壤(黑土、潮土和红壤)及1种水田土壤(水稻土)活性有机碳含量(LOC)及碳库管理指数(CMI)的影响,为优化施肥管理措施提供科学依据。结果表明:水田土壤总有机碳含量(TOC)和LOC含量高于旱作土壤。单施化肥(NPK),旱作3种土壤TOC、LOC较不施肥对照(CK)显著增加,而水田较CK无显著差异。化肥配施秸秆处理(NPKS),旱作和水田土壤TOC、LOC、活性有机碳占总有机碳的比例(LOC/TOC)及CMI均显著增加,潮土TOC和LOC含量增加最多,增加比例分别为37.6%和66.9%。化肥配施有机肥处理(NPKM),旱作和水田土壤的TOC、LOC、LOC/TOC及CMI均显著增加,其中黑土增加比例最大,分别为90.3%、140.9%、5.1%及277%。旱作和水田土壤的活性有机碳及碳库管理指数均对施肥响应敏感,具有相对一致的响应特征,即长期有机无机肥配施能显著提高土壤活性有机碳含量及碳库管理指数,且效果优于化肥配施秸秆和单施化肥处理。

To provide scientific basis for optimizing fertilization management measures,effects of long-term fertilization on labile organic carbon（ LOC） and carbon management index（ CMI） in three upland soils（ black soil,fluvo-aquic soil and red soil） and one paddy soil in China were studied. The results showed that the mean values of total organic carbon（ TOC） and LOC in paddy soil were higher than those in upland soils. For chemical fertilizer treatment（ NPK）,the TOC,LOC and CMI in the three upland soils slightly increased compared with the control treatment（ CK）,while there was no significant difference in paddy soil. For chemical fertilizer with straw treatment（ NPKS）,the TOC,LOC,the proportion of LOC to TOC（ LOC/TOC） and CMI significantly increased both in upland soils and paddy soil,of which the TOC and LOC increased most in fluvoaquic soil by 37. 6% and 66. 9%,respectively. For chemical fertilizer with manure treatment（ NPKM）,the TOC,LOC,LOC/TOC and CMI increased markedly among all treatments in upland soils and paddy soil,and increased most in the black soil by 90. 3%,140. 9%,5. 1% and 277%,respectively. In conclusion,LOC and CMI in upland soils and paddy soil had the same response under different fertilization treatments. Chemical fertilizer combined with manure significantly increased the LOC and CMI with the order of NPKM NPKS NPK.