紫云英与化肥配施对土壤微生物特征和作物产量的影响

摘要

为了探讨紫云英绿肥与化肥配施对稻田土壤培肥的微生物机制，本研究以7年肥料定位试验为材料，研究了不同施肥对安徽沿江双季稻区稻田土壤可培养微生物数量、微生物量碳氮、微生物熵及水稻产量的影响，探讨施用紫云英绿肥对稻田土壤的培肥效果。结果表明，1）与不施肥相比，长期施用紫云英可显著增加土壤微生物总数量（58．09％～86．86％），尤其是增加了细菌数量（77．93％～112．76％），土壤微生物总数量及细菌数量均于 G3 F1处理（70％化肥配施22500 kg／hm2紫云英）达最大值（288．26×104和263．95×104 CFU／g）。2）施用紫云英可有效增加土壤微生物量。其中，70％化肥配施中高量紫云英的处理与 CK 相比，土壤微生物量碳（SMBC）、微生物量氮（SMBN）、微生物熵（qMB）分别增加了102．77％～113．94％、172．53％～185．17％、69．47％～84．65％；与100％化肥相比，SMBC、SMBN、qMB 分别增加27．74％～34．77％、74．14％～82．22％、20．50％～31．29％。（3）施用紫云英处理的水稻产量与100％化肥处理相当或稍有提高，但明显高于70％化肥和 CK 处理。与 CK 相比，紫云英与化肥配施可提高产量46．22％～51．44％。因此，化肥减量30％配施15000～30000 kg／hm2紫云英可以提高安徽沿江双季稻区水稻产量，本试验以施加22500 kg／hm2的紫云英产量最高（增产率达51．44％），同时，紫云英与化肥配施对提高土壤微生物量碳氮、微生物熵及调节土壤微生物群落组成，改善稻田土壤生物学性状产生显著影响。%To explore the microbiological response to incorporation of Chinese milk vetch and chemical fertilizers in paddy soils,a 7-year field experiment was used to investigate the effects of different fertilization regimes on the number of microorganisms,microbial biomass carbon (SMBC)and nitrogen (SMBN)contents,soil micro-bial quotient (qMB)and rice yield.The results showed that:(1 )Compared to the control (CK),long-term use of milk vetch significantly increased soil microorganisms by 58.1%-86.9%,especially the number of bac-teria (77.9%-112.8%).The highest soil microorganism and bacteria numbers were found in the 70% mineral fertilizer combined with 22500 kg/ha milk vetch treatment with value of 288.26×104 and 263.95×104 CFU/g, respectively.(2)Application of milk vetch can effectively increase the content of microbial biomass.Compared with CK,70% of normal mineral fertilizer application combined with milk vetch increased SMBC,SMBN, qMB by 102.8%-113.9%,172.5%-185.2% and 69.5%-84.7% respectively.Compared with 100% min-eral fertilizer treatment,70% mineral fertilizer application combined with milk vetch increased SMBC,SMBN, qMB by 27.7%-34.8%,74.1%-82.2%,20.5%-31.3% respectively.(3)70% mineral fertilizer applica-tion combined with milk vetch incorporation maintain or improved crop yields compared with 100% the mineral fertilizer treatment,but significantly increased crop yields compared with CK and the 70% mineral fertilizer treatment.Compared with CK,mineral fertilizer application combined with milk vetch increased crop yield by 46.2%-51.4%.It was concluded that mineral fertilizer reduction of 30% combined with milk vetch can in-crease the rice yield in Anhui double cropping areas along the Yangtze River.In this experiment,the applica-tion of 22500 kg/ha milk vetch achieved the highest yield increase (51.44%).Application of 70% mineral fer-tilizer combined with milk vetch plays a significant role in increasing soil microbial biomass and soil microbial quotient,regulating soil microbial community composition as well as improving soil biological properties in paddy soil.