紫云英与化肥配施对土壤微生物特征和作物产量的影响

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G₃F₁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。

Effects of Chinese milk vetch manure and fertilizer on soil microbial characteristics and yield of rice

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.