节水与减氮措施对稻田土壤微生物和微动物群落的影响  

Influences of water-saved and nitrogen-reduced practice on soil microbial and microfauna assemblage in paddy field

作　　者：桂娟[1] 陈小云[1] 刘满强[1] 庄喜平 孙震[1] 胡锋[1] 

机构地区：[1]南京农业大学资源与环境科学学院,南京210095

出　　处：《应用生态学报》2016年第1期107-116,共10页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(31170487);中央高校基本科研业务费项目(KYZ201207);南京农业大学SRT项目(1413A09)资助~~

摘　　要：水稻生产中的水肥消耗量过大引起的资源环境问题已经引起了普遍关注.本研究分别在水稻分蘖期和成熟期采样,比较了灌溉方式(常规灌溉和节水25%)和施氮水平(常规高氮和减氮40%)对稻田土壤微生物及微动物群落的影响.结果表明:与常规灌溉相比,节水控灌显著降低了分蘖期土壤pH值.土壤可溶性有机碳氮和微生物生物量碳氮均受到灌溉和氮肥及两者交互作用的显著影响.节水或减氮降低了可溶性有机物含量;节水提高了微生物生物量碳而显著降低了微生物生物量氮.节水显著提高土壤硝态氮含量而使铵态氮含量呈下降趋势.在水稻分蘖期,节水处理下土壤细菌、真菌、放线菌和原生动物的生物量高于常规灌溉,而在水稻成熟期,相对应的变化趋势则相反.灌溉、氮肥及两者的交互作用显著影响轮虫数量和食微线虫的比例.在水稻分蘖期,节水灌溉处理土壤轮虫、线虫数量及食细菌线虫比例有提高的趋势;减氮增加了土壤轮虫数量却减少了线虫数量.总之,土壤微生物和微动物群落对节水减氮农业措施的响应不同,不仅与水稻不同生长期有关,而且与水氮之间及食物网内各类群之间的复杂交互作用有关.The resource and environmental problems caused by excessive consumption of water and fertilizer in rice production have recently aroused widespread concern. This study investigated the effects of irrigation modes（ conventional irrigation and 25% water-saved irrigation） and different N application rates（ conventional high-nitrogen fertilization and 40% nitrogen-reduced fertilization） on microbial and microfauna assemblages at tillering and ripening stages in paddy field. The results showed that compared with conventional irrigation（ CF）,water-saved irrigation（ WS） decreased the soil p H at tillering stage. Soil dissolved organic matter（ dissolved organic C and N） and microbial biomass C and N were significantly affected by irrigation,nitrogen fertilizer and their interactions. WS or N-reduced fertilization（ LN） decreased the contents of dissolved organic matter; WS increased microbial biomass C but decreased microbial biomass N. Nitrate was significantly higher in WS than CF,while ammonium showed reverse pattern. At tillering stage,the soil microbial biomass from bacteria,fungi,actinomy and protozoa was higher in WS than in CF,but the trend was opposite at ripening stage. There was a significant interation between irrigation and fertilization on soil rotifer numbers and microbial-feeding nematodes. At tillering stage,WS increased the numbers of rotifer and nematode, and also the proportion of bacterial-feeding nematode; LN increased the abundance of rotifer but decreased the abundance of nematode. In summary,soil microbial and microfauna assemblages showed different response to water-saved and nitrogen-reduced agricultural managements,which depended on different crop growth stages,but also the complex interactions of water and nitrogen and between biological groups in food webs.

关 键 词：灌溉 氮肥 农田 微生物群落 微型动物 

分 类 号：S154.3[农业科学—土壤学]