长期施肥对土壤有机氮组成的影响

 采用 196 5年Bremner提出的土壤有机氮分级方法 ,对 15年有机肥与化肥定位试验中的耕层土壤有机氮组成进行了分级。结果表明 ,长期施用化肥和有机肥对土壤全氮和土壤有机氮组成有显著影响。与单施氮磷化肥相比 ,有机肥与化肥配合施用显著提高了土壤全氮、酸解性氮与非酸解性氮的含量 ;但在酸解性氮中 ,氨基糖氮显著下降 ,而酸未知氮极显著增加。与不施氮相比 ,施用氮肥显著提高了土壤全氮、酸解性氮与非酸解性氮的含量 ;在酸解性氮中 ,氮肥显著提高了氨态氮的含量但降低了氨基糖氮的含量 ,氨基酸态氮和酸未知氮的含

Effects of Long-term Fertilization on Soil Organic Nitrogen Fractions

Organic nitrogen (N) forms in soil were quantified in a 15-year fertilization trial using the method proposed by Bremner in 1965. Results showed that soil total nitrogen and organic nitrogen fractions were significantly influenced by long-term application of chemical fertilizer and manure. Compared with application of N and P fertilizers, manure with N and P fertilizers greatly increased the contents of total N, acid hydrolysable N and nonhydrolysable N. Of the forms of acid hydrolysable N, hydrolysable unidentified N (HUN) was significantly increased but amino sugar N significantly decreased by manure with N and P fertilizers. Similar to manure with chemical fertilizer, N application significantly increased total N, acid hydrolysable N and nonhydrolysable N compared to the plots without N addition. N fertilizer significantly increased ammonium N but decreased amino sugar N, whereas the increase in amino acid N and HUN was not obvious. In contrast, P application did not significantly affect total N and organic N forms.