以华北地区冬绿肥翻压 7 年潮土为研究对象,设不同冬绿肥及其混播 7 种处理方式,采用Bremner酸解法研究了不同冬绿肥翻压对土壤有机氮各组分变化规律的影响.结果表明:供试土壤中酸解有机态氮总氮占全氮的74.81%,其中各形态氮含量排列顺序为:未知态氮>氨基酸态氮>酰胺态氮>氨基糖态氮;长期翻压冬绿肥土壤中氮素主要向酸解总氮转化,不同冬绿肥以黑麦草(RG)、二月兰(OV)和毛叶苕子二月兰混播(VR+OV)酸解总氮增加较多;2020 年冬闲田土壤氨基酸态氮和氨基糖态氮均低于 2013 年,而翻压冬绿肥土壤氨基酸态氮和氨基糖态氮均高于 2013 年,以翻压黑麦草和二月兰增加最多;2020 年土壤酰胺态氮和未知态氮均高于 2013 年,并且翻压不同绿肥土壤的酰胺态氮和未知态氮也均高于冬闲田;相关和通径分析表明,土壤中氨基酸态氮与碱解氮正相关系数和直接通径系数最大,氨基糖态氮和未知态氮与碱解氮也呈显著正相关,直接通径系数在 2 以上.
The effects of 7 different kinds of winter green manure on soil organic nitrogen components were studied by Bremner acid hydrolysis method using 7 kinds of winter green manure and mixed sowing methods in fluvo-aquic soil of northern China.The results showed that total acidolysis nitrogen accounted for 74.81%of total nitrogen in the soil organic nitrogen.In the soil organic nitrogen,the content of nitrogen in various forms was ranked as unknown nitrogen>amino acid nitrogen>amide nitrogen>amino sugar nitrogen.The nitrogen in the soil of winter green manure under long-term overturning pressure was mainly transformed into acidolysis nitrogen.The total nitrogen of different winter green manure increased significantly in RG,OV and VR+OV.In 2020,the soil amino acid nitrogen and amino sugar nitrogen were lower than those in 2013,while the soil under winter green manure treatments were higher than those in 2013,with RG and OV increasing the most.In 2020,the soil amide nitrogen and unknown nitrogen were higher than those in 2013,and the soil under different green manure treatments were higher than those in winter fallow field.Correlation and path analysis showed that the positive correlation coefficient and direct path coefficient between amino acid nitrogen and alkali-hydrolyzed nitrogen were the largest in soil,and the positive correlation between amino sugar nitrogen and unknown nitrogen and alkali-hydrolyzed nitrogen was also significant,and the direct path coefficient was above 2.