盐渍化土壤上不同类型氮肥氨挥发损失特征研究

在室内采用"磷酸甘油-海绵通气法",对不同类型氮肥在典型非盐渍化土壤、盐化土壤,碱化土壤上的氨挥发损失特征进行研究。结果表明:(1)在相同的施氮量情况下,占施入量1.34%~27.74%的氮以NH3的形式挥发损失;(2)除硝酸钙外,随着土壤盐渍化程度的增加,不同类型氮肥氨挥发损失均随之增加,挥发速率与盐渍化类型有关;(3)不同盐渍化类型土壤上的氨挥发量均为碳酸氢氨>尿素>硝酸铵,硝酸钙几乎不发生氨挥发;因此盐渍土上选择硝态氮肥不失为降低氨挥发损失的一种选择;(4)过量盐分的存在对于氮肥硝化作用的抑制是导致盐渍化土壤上氮肥氨挥发损失增加的主要原因。

Study on Ammonia Volatilization Characteristics of Different Types of N Fertilizers in Salinization Soils

Using the method of phosphoric acid and glycerol-sponge venting indoor,the characters of ammonia volatilization on different forms of N fertilizer in Non-saline soil,Salt-affected soil,Alkaline soil were studied.The results showed that(1)1.34%～27.74% of N in fertilizing amount were volatilized by the forms of NH3 in the same amounts of N;(2)With the degree of soil salinity increased,different types of nitrogen fertilizer ammonia volatilization losses were increased but the fertilizer of Ca(NO3)2,and the volatile rate with the salinization stypes were related;(3) The amount of ammonia volatilization in different types of salinization soil were NH4HCO3>CO(NH2)2>NH4NO3,there was almost no ammonia volatilization in the form of Ca(NO3)2;So,in order to reduce the ammonia volatilization in salinization soil,choosing the NO3——N fertilizers was a good way;(4) The existence of excessive salt restraining the nitrification of N fertilizers was one of reasons that the loss of the ammonia volatilization in salinization soils was increased.