【摘要】 为了明确肥料氮素在模拟土柱中的迁移转化特征,通过布置室内模拟土柱试验,研究了3倍常规施肥水平下(360mg.kg-1)水稻土中矿质氮的变化.结果表明:不同处理、不同土层间NH4+-N和NO3--N含量差异显著.不施肥对照在整个培养期间养分含量变化不大,不同土层间亦没有显著性差异.施用尿素和硫铵后,土壤NH4+-N和NO3--N含量显著提高,尤其是0～50mm土层内,分别达到186.0～2882.1mg.kg-1和268.7～351.5mg.kg-1,分别相当于对照的4.8～242倍和5.7～316倍,50mm以下各土层与对照处理相似,表明肥料氮素的迁移转化主要发生在0～50mm土层内,并且在培养的前14d变化最大.整个培养期间不同土层内,硫铵处理不同矿质态氮含量是尿素处理的0.7～2.0倍,硝化率是尿素处理的0.9～1.4倍,表明硫铵在水稻土中的转化效率略高于尿素.更多还原

【Abstract】 Aimed to understand the translocation and transformation characteristics of applied fertilizer nitrogen in paddy soil,a simulated soil column experiment was conducted in laboratory to study the variations of soil mineral nitrogen along the profile under the application of 360 mg·kg-1(3 folds of conventional application rate) of urea-and ammonium sulfate nitrogen.In the experimental period,the soil NH4+-N and NO3--N contents in the control(no fertilization) had less change,and no significant differences among different soil layers.Applying urea-and ammonium sulfate nitrogen resulted in a significant increase of soil NH4+-N and NO3--N in 0-50 mm layer,being 186.0-2882.1 mg·kg-1 and 268.7-351.5 mg·kg-1,and 4.8-242 times and 5.7-316 times of those in CK,respectively.However,the NH4+-N and NO3--N contents below 50 mm soil depth were similar to those in CK,indicating that the translocation and transformation of applied fertilizer nitrogen mainly occurred in 0-50 mm soil layer.The translocation of fertilizer nitrogen mostly occurred in the first 14 days after fertilization.In the whole experimental period,the NH4+-N and NO3--N contents in each soil layer under the application of ammonium sulfate were 0.7-2.0 times of those under the application of urea,and the nitrification rate was 0.9-1.4 times of that,suggesting the higher transformation rate of applied ammonium sulfate in paddy soil,as compared with applied urea.更多还原