克氏原螯虾-水稻连作对土壤微生物功能多样性的影响

为了研究克氏原螯虾-水稻连作对系统土壤微生物功能多样性的影响。分别选择克氏原螯虾-水稻连作塘、水稻田为研究对象,采用Biolog-ECO方法检测土壤样品中微生物对31种碳源的利用能力,研究克氏原螯虾-水稻连作田和单纯水稻田中微生物代谢活性及代谢多样性差异,并分析其影响因素。结果表明,克氏原螯虾-水稻连作田土壤中氮、磷、钾和有机质的含量和微生物代谢活性均显著低于水稻田,“虾-稻”连作田和水稻田土壤微生物代谢多样性间也存在显著差异(P<0.05)。冗余分析的结果表明,这种差异和土壤有机质含量具有显著的相关性(R²=0.814,P =0.001)。克氏原螯虾-水稻连作对土壤微生物功能多样性能够产生显著影响。肥料使用量的降低、使用方式的改变,特别是其中有机质含量的降低是造成影响的重要原因。

Continuous Cropping of Crayfish and Rice: Effects on Functional Diversity of Soil Microorganisms

To investigate the effects of continuous cropping of crayfish and rice on functional diversity of soil microorganisms, some rice paddy fields and ponds with continuous cropping of crayfish and rice were selected as research objects, Biolog-ECO method was used to detect the utilizing capacity of 31 carbon sources by microorganism in soils. The metabolic activity and the difference of metabolic diversity of microorganism were studied in the rice paddy fields with continuous cropping of crayfish and rice and rice paddy field. The influencing factors were analyzed. The results showed that the contents of nitrogen, phosphorus, potassium and organic matter, and the microbial metabolic activities in fields with continuous cropping of crayfish and rice were all lower than that in rice paddy fields (P<0.05). The metabolic diversities of soil microorganisms in fields with continuous cropping of crayfish and rice and rice paddy fields were significantly different (P<0.05, and the results of redundancy analysis showed that and the difference was positively correlated with the content of organic matter in soil (R²=0.814, P =0.001). To sum up, the continuous cropping of crayfish and rice can influence the functional diversity of soil microorganisms significantly, and the reduction of fertilizer uses, especially the reductions of organic matter, is the important cause.