不同肥料类型对土壤酶活性与微生物数量时空变化的影响

采用等氮技术进行原状土柱法试验,研究了不同肥料类型对土壤酶活性和微生物数量时空变化的影响。结果表明,柱栽条件下,不同肥料类型对土壤酶活性和微生物数量的时空变化有明显影响。不同土壤深度脲酶和蛋白酶总活性均表现为肥料配施>有机肥>尿素;土壤脲酶活性均随土壤深度的增加而下降,0~20 cm土层的土壤脲酶活性占全生育期1.2 m土层总活性的50%以上,0~40 cm土层占79%左右,在0~20 cm和20~120 cm的土层所占比例大致相当;不同土层的脲酶活性均在拔节期达到最高;在小麦生育后期,脲酶活性在不同土壤深度表现为升高的趋势。3种肥料类型处理不同土层的蛋白酶活性均在成熟期达到最大值,其次为拔节期,在拔节期和扬花期出现峰值,在抽穗期和灌浆盛期出现低谷,其最小值出现在灌浆盛期;土壤蛋白酶在20~40 cm和80~100 cm时出现峰值,并在20~40 cm土层时活性最高。3种肥料类型处理间比较,微生物数量均表现为肥料配施>有机肥>尿素。在同一土层中的细菌数量以苗期最大;真菌数量以抽穗期最大;放线菌随着小麦生育期的推进数量逐渐增加,成熟期达最大值。在小麦不同生育时期,以20~40 cm土层中的细菌、真菌和放线菌数量最大,0~20 cm土层次之,40~120 cm土层随土层深度加深数量逐渐减少。

Studies on Spatial-Temporal Variations of Soil Enzyme Activities and Microorganism's Number under Different Fertilizer Types

The experiment of using soil column methods which studied the effects of different fertilizers types on the temporal-spatial variations of soil enzyme activities and microorganism's number was conducted under the condition of equal nitrogen and three treatments were installed which included carbamide treatment,organic fertilizer treatment and mixed fertilizer treatment.The results showed that the effects of different fertilizers types on the temporal-spatial variations of soil enzyme activities and microorganism's number were obvious under the condition of soil column methods.The total urease and protease activities in different soil depth showed mixed fertilizer treatment >organic fertilizer treatment>carbamide treatment without exception;the total urease activities decreased with the increasing soil depth without exception,the urease activities in the soil layers of 0~20 cm and 0~40 cm respectively took possession of the total urease activities in the total soil of 1.2 m with 50% upwards and 79% during the whole growth stages of wheat,the proportion of 0~20 cm and 20~120 cm was approximately equal;the max value of urease activities in different soil layers occurred during jointing stage;the urease activities increase during latter growth stage in different soil depth.The max value of protease activities occurred during mature stage,in the next place during jointing stage,the peak value occurred during jointing and flowering stages,the off-peak value occurred during booting and active grain filling stages,the min value occurred during active grain filling stage in different soil layers under three different fertilizers types treatment;the peak value of soil protease activities occurred in the soil layer of 20~40 cm and 80~100 cm,protease activities in the soil layer of 20~40 cm were higher than 80~100 cm.The number of microorganisms showed mixed fertilizer treatment > organic fertilizer treatment>carbamide treatment without exception.The max number of bacteria occurred during over-winter stage,the max number of fungi occurred during booting stage in the same soil layer.The number of actinomyces increased with the advance of growth stages,the max value occurred during mature stage in the same soil layer.The max number of bacteria,fungi and actinomycets occurred in the soil layer of 20~40 cm,in the next place in the soil layer of 0~20 cm, the number decreased with the increasing depth of 40~120 cm soil layer during the different growth stages of winter wheat.