不同施肥措施对华北潮土区玉米田土壤线虫群落的影响

Effects of Different Fertilization Regimes on Maize Field Nematode Community in Fluvo-aquic Soil in North China

为研究长期不同施肥处理对华北潮土土壤线虫群落结构的影响,试验在农业部环境保护科研监测所武清试验站开展,对对照(A0)、单施有机肥(A1)、化肥减量50%配施有机肥(A2)、常规化肥配施有机肥(A3)、化肥增量50%配施有机肥(A4)、单施化肥(A5)等6个长期定位试验地的土壤线虫进行调查,分析其群落组成和生态结构。结果表明,所有处理共鉴定出18个线虫属,其中A0、A1、A2、A3、A4、A5分别有16,17,18,16,15,14个属;螺旋线虫属是华北潮土区玉米田主要线虫属;单施化肥(A5)降低了线虫种类、线虫总量及各营养类群数量,不利于食物网稳定;有机肥和化肥配施处理中(A2～A4),随化肥施用量的增加,线虫总量、食细菌性线虫、食真菌性线虫数量呈下降趋势,植食性线虫、杂食-捕食性线虫数量呈先增加后降低的趋势,同时施用过量化肥对线虫种类有明显抑制作用,使物种多样性下降,不利于线虫群落结构稳定。综合来看,化肥减量50%配施有机肥(A2)在改善土壤养分状况的同时可降低土壤环境干扰程度,稳定食物网,更有利于线虫群落稳定,而且也减少环境污染,符合国家控制化肥施用的政策。

In order to better understand the influence of different fertilization regimes on nematodes community of maize field in fluvo-aquic soil,this study was conducted in the Wuqing experimental station,Agro-Environmental Protection Institute,Ministry of Agriculture.The field experiment included six treatments,i.e.,contrast(A0),organic fertilizer(A1),reduce50%chemical fertilizer plus organic fertilizer(A2),normal chemical fertilizer plus organic fertilizer treatment(A3),increase50%chemical fertilizer plus organic fertilizer(A4),chemical fertilizer(A5).The nematodes community composition and ecological structure were analyzed.The results showed a total of18nematode genera were found in all the treatments,in which A0,A1,A2,A3,A4and A5had16,17,18,16,15and14genera,respectively.Helicotylenchus was dominant genus.The chemical fertilizer treatment(A5)reduced the species and the total amount of nematodes,and also the number of each nematode nutrient group,which was not beneficial to the stable of soil nematode community structure.In the combination of chemical fertilizer and organic fertilizer treatments(A2-A4),total amount of nematodes,number of bacterivores and fungivores had a downward trend with the increasing of the amount of chemical fertilizer,while the number of bivorous and omnivores-predatores increased first and then decreased.The combination of excessive chemical fertilizer and organic fertilizer reduced the evenness distribution of nematode species,made the species diversity to decrease,which was not conducive to the stability of the nematode community structure.In conclusion,the treatment of reduced50%chemical fertilizer plus organic fertilizer(A2)could improve the soil nutrient,reduce the degree of soil disturbance,stabilize the food network,and be more conducive to the stability of the nematode community.It also reduced environmental pollution and accorded with the state's policy of controlling fertilizer application.