蚯蚓粪对豇豆土壤活性有机碳及微生物活性的影响

Effects of Vermicompost on Active Organic Carbon and Microbial Activity in Cowpea Soil

为探讨施用蚯蚓粪对豇豆土壤活性有机碳与微生物活性的作用效果,通过大田试验,研究CK(对照,不施肥)、CF(单施化肥)、VC(蚯蚓粪)和VC+CF(蚯蚓粪和化肥各提供50%的氮)等处理对豇豆土壤活性有机碳、碳库管理指数(CPMI)、微生物量碳氮及微生物呼吸、代谢熵的影响。结果表明,与CF相比,施用蚯蚓粪处理的活性、中活性和高活性有机碳含量均显著升高。VC+CF的活性有机碳含量与CPMI明显高于其它处理,较CF分别高出30.38%和36.69;同时,微生物量碳、氮含量亦显著高于其它处理。此外,VC+CF还明显增强了土壤微生物呼吸作用,但降低了代谢熵,其中土壤微生物呼吸分别比CK、CF和VC提高64.91%、36.23%和16.05%,而代谢熵分别下降10.85%、9.06%和5.32%。与VC+CF相比,VC对豇豆土壤的影响作用较小。相关性分析表明,土壤不同程度的活性有机碳、CPMI与微生物活性之间呈显著或极显著的相关性,各指标之间具有密切的内在联系。综上所述,蚯蚓粪与化肥配施能明显提高豇豆土壤的活性有机碳含量,且能显著增强土壤微生物活性。该研究为豇豆的合理施肥提供了理论依据。

In order to explore effect of vermicompost application on active organic carbon and microbial activity of cowpea soil,a field experiment was conducted including four treatments,i. e. CK（ neither urea nor vermicompost was applied）,CF（ 100% of nitrogen was provided by urea）,VC（ 100% of nitrogen was provided by vermicompost）,and VC ＋ CF（ 50% and 50% of nitrogen was provided by vermicompost and urea,respectively） to determine the effects of different treatments on active organic carbon,carbon pool management index（ CPMI）,microbial biomass carbon,microbial biomass nitrogen as well as microbial respiration and metabolic quotient in the soil of cowpea. Results indicated that in comparison with CF treatment,vermicompost application significantly increased the contents of active organic carbon,mid-active organic carbon and highly active organic carbon. The active organic carbon content and CPMI in VC ＋ CF treatment were obviously higher than other treatments,showing 30. 38% and 36. 69 increases compared with CF treatment,respectively. Meantime,the VC ＋ CF treatment significantly increased the contents of microbial biomass carbon and microbial biomass nitrogen. Additionally,the microbial respiration was evidently enhanced by the use of VC ＋ CF treatment,while the metabolic quotient was decreased,indicative of 64. 91%,36. 23% and 16.05% increases in microbial respiration over the treatments of CK,CF and VC,respectively. And the metabolic quotient was reduced by 10. 85%,9. 06% and 5. 32%,respectively. However,in VC treatment,less effect on micro-domain environment characteristics was observed than that in VC ＋ CF treatment. Correlation analysis revealed that the correlation among different degree of soil active organic carbon,carbon pool management index and microbial activity reached significant or extremely significant level, showing close inner link among every indicator. As a result,vermicompost co-applied with inorganic fertilizer can significantly increase the active organic carbon content and enhance the microbial activity of cowpea soil. This study provides the theoretical basis for the rational fertilization of cowpea.