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采用Bremner1 965年提出的土壤氮素分级方法 ,对 1 6年肥料长期定位试验中的耕层以及剖面各层次土壤的氮素形态进行了分级。结果表明 ,施用化肥不能提高耕层土壤各形态氮的含量 ,对土壤氮素的组成也无明显的影响 ;有机肥和化肥配合施用 ,耕层土壤各形态氮的含量都有不同程度的提高 ,其中氨基酸态氮的增加最为明显。有机无机肥配合施用 ,可提高土壤氮素的储量和质量 ,不仅对耕层土壤氮素的含量和组成有影响 ,而且对耕层以下土壤各形态氮的含量也有一定的影响。一般随着有机肥用量的增加 ,下层土壤各形态氮含量的增加幅度也越大 ,而且影响深度也更深。在本试验条件下 ,施肥对氮素形态的最大影响深度为 30cm左右。
The soil nitrogen classification method proposed by Bremner in 1965 was used to classify the nitrogen forms of the topsoil and the soil of different layers in the long-term fertilization experiment of 16 years. The results showed that the application of chemical fertilizers could not increase the content of nitrogen in topsoil, and had no obvious effect on the composition of soil nitrogen. With the application of organic manure and chemical fertilizers, the content of nitrogen in topsoil increased with different degrees, One of the most significant increase in amino acid nitrogen. The combination of organic and inorganic fertilizers can increase the reserves and quality of soil nitrogen, which not only affects the content and composition of soil nitrogen but also influences the content of various forms of nitrogen in the soil below tillage. In general, with the increase of organic manure, the increase of nitrogen content in the lower soil layer is also larger, and the depth of influence is deeper. Under the experimental conditions, the maximum depth of fertilization on nitrogen forms is about 30cm.