玉米栽培模式与施肥方式对土壤微生物和土壤肥力的影响

Effect of corn cultivation mode and fertilization on soil microbial biomass and soil fertility

为建立科学的栽培模式和施肥方式,提高土壤生物肥力和实现土壤可持续利用。本研究采用常规裸地栽培玉米和地膜覆盖栽培玉米2种模式下的不同的施肥方式,测定多个微生物指标,土壤的养分和理化特性指标。结果表明:1)栽培模式对土壤温度和含水量的影响,在不同时期,两者的差异性不同;2)各种微生物指标影响系数的绝对值从大到小为:细菌、固氮菌,防线菌和真菌。土壤理化特性及养分指标影响系数的绝对值从大到小为:有机质、土壤pH、碱解N、全N、全P、速效K、速效P、土壤含水分量和土壤温度。不同模式下两指标变量组之间有极其显著的相关系数-0.932 1;3)不同栽培模式对不同施肥处理的重要性影响不大。只要含N,是否含P、K对微生物的影响不明显。复合施肥对土壤理化特性及养分有重要影响.由此可以得出:不同的栽培模式仅在苗期前期和成熟后期,对土壤温度和含水量的影响存在差异,并且不同栽培模式对不同施肥处理的重要性及各指标无显著影响。各种微生物和各个土壤理化特性及养分指标间存在复杂的关系。

In order to establish a more reasonable fertilization system,improve soil biological fertility and maintain soil sustainable utilization,an experiment was conducted.Corns were planted in conventional no mulch fields and plastic mulch ones,respectively.Different fertilizers were all applied in two modes.Soil microbes,fertility and physo-chemical properties from each soil samples were analyzed.The result showed that:1)In different periods,soil temperature and moisture showed inconsistent significant differences under both plastic mulch mode and no mulch one.2)The absolute values of effective coefficient from soil microbial index were ranked as follows:bacteria > azotobacterium > actinomycete>fungi,and those from soil physico-chemical characteristics were done:soil organic matter> pH value >hydrolysable nitrogen(N)>total N > total phosphorus(P)> available potassium(K)> available P > soil moisture> soil temperature.A significant negative correlation(r=-0.932 1)was detected between the microbial populations and soil physico-chemical properties under different cultivation mode.3)Different cultivation modes had little impact on the importance of different fertilization treatments.While the N fertilizer was added,the P and K fertilizers had little effect on soil microbes.Compound fertilizer had important impact on soil physico-chemical properties and nutrients.In conlcusion,our results indicated that different cultivation modes influenced soil temperature and moisture only in the early seedling stage and the later mature stage.There were also no significant effects between different cultivation modes and the different fertilization treatments.Complex relationship existed among various microbes,soil physicochemical properties and nutrient levels.