摘要
采用室内培养试验方法，模拟蘖肥施用后氮素转化过程。试验土壤为采自黑龙江省建三江白浆土型水稻土（JSJ）和庆安草甸土型水稻土（QA），采用通气法测定NH，挥发损失，并测定水层pH，以及水层和不同土层中NH：-N和尿素态氮含量。试验结果显示，施用尿素后短期内水层pH显著提高，随后pH甚至低于不施氮肥处理，pH增加因土壤而异；随施肥时间推移，水层中氮不断减少，进入土壤中以及挥发损失的氮不断增加。JSJ氨挥发累积量占施氮量13．68％～14．42％，氮量和氨挥发为线性关系；QA氨挥发占施氮量3．39％～7．96％，随施肥量增加氨挥发比例增大。施肥后3d，水层氮占总施肥量24％～33％，有60％～70％氮扩散到土壤中；施肥后10d水层氮只占施肥量5．0％～6．3％；施肥后21d，进入到土壤中氮比例为66％～85％，在pH较低土壤中所占比例更大。尿素转化后铵态氮主要集中在0-2和2-4cm土层，下层土壤铵态氮含量较低，短期内表层土壤铵态氮可反映施肥变化。施肥后第21天，两地氮素回收率分别为75．71％～86．37％和85．32％～98．29％，另有少量氮进入有机氮库或通过反硝化损失。
Laboratory study was conducted to study the transformation process of applied urea-N fertilizer. The tested soils were albic rice soil from Jiansanjiang and meadow paddy soil from Qing＇an in Heilongjiang Province. Every chamber was sampled to determine the pH in water, the ammonia volatilization loss, NH4＋-N and urea-N contents in water and different soil layers after nitrogen fertilizer application. Experiment results showed that pH in the water layer increased significantly within short-term after fertilization, then decreased and even lower than no urea treatments subsequently. The pH in water differed from soil types. The accumulated ammonia losses in the treatments of N applied in JSJ and QA were 13.68%-14.42% and 3.39%-7.96%, respectively, with clearly positive liner and exponential correlations （P〈0.05）. There were 60%-70% applied N diffused into soil on the 3rd day after fertilization. The N in water was accounted for 24%-33% of total application N rate, corresponding value was 5.0%-6.3% on 10 days. The 66%-85% of N diffused into soil on 21 days after fertilization. Meanwhile, soil with low pH had high proportion N in soil layer. The NH4＋-N, as the hydrolysis products of urea, were mainly concentrated in 0-2 cm and 2-4 cm soil layer, while muted impact on the lower soil layer. The NH4＋-N content of surface soil shortly after urea application could react the variation of fertilization. The N recovery rates at 21st day after fertilization were 75.71%-86.37% in JSJ and 85,32%- 98.29% in QA, respectively. There were small amout of applied N transformed to organic-N or lost through denitrification.
出处
《东北农业大学学报》
CAS
CSCD
北大核心
2015年第12期24-32,共9页
Journal of Northeast Agricultural University
基金
国家自然科学基金(41101281)
关键词
尿素
氨挥发
土壤
铵态氮
PH
urea
NH3 volatilization
soil
ammoniam
pH
