不同施肥制度对褐土有机氮及其组分的影响

Effect of Different Fertilization Regimes on Organic Nitrogen and Its Fractions in Cinnamon Soil

为探讨施肥对土壤有机氮及其组分含量的影响,通过8年田间定位试验,研究了长期不同施肥制度下褐土有机氮及其组分的变化规律。结果表明,与试前比较,不施肥主要消耗氨基酸氮和铵态氮,土壤酸解性总氮及氨基酸态氮、铵态氮、氨基糖态氮含量均显著减少,进而造成全氮含量下降。单施常量NPK化肥处理土壤全氮、酸解性总氮和氨基酸态氮出现下降趋势,氨基糖态氮含量显著降低,铵态氮含量则呈增加态势;增量NPK化肥处理主要通过提高铵态氮含量使酸解性总氮和土壤全氮略有盈余;有机肥(物)料配施常量NPK化肥各处理则表现为酸不溶性氮含量降低,并通过有效增加氨基酸态氮、铵态氮和氨基糖态氮含量进而使土壤酸解性总氮及全氮含量显著提高,增强土壤氮素供应水平。有机氮积累过程中,化肥氮主要进入土壤铵态氮和氨基酸态氮库,而有机肥(物)料氮则主要进入土壤氨基酸态氮库。

In order to study the effects of fertilization on soil organic nitrogen and its components,eight years＇ location experiment was conducted in cinnamon soil in Hebei Province to study the changes of soil organic nitrogen and its fractions under different fertilization regimes. The results showed that no fertilization mainly consumed amino acid N and ammonium N,remarkably decreased the content of total hydrolysable N,amino acid N,ammonium N and amino sugar N,and then decreased the content of total N. Application of constant NPK fertilizer decreased the content of total N,total hydrolysable N and amino acid N,remarkably decreased the content of amino sugar N,and enhanced the content of ammonium N. Application of increment fertilizer mainly raised the content of ammonium N,the content of total N and total hydrolysable N rose. Organic mature combined with constant NPK fertilizer decreased non-hydrolysable N,effectively increased the content of total N and total hydrolysable N by increasing soil amino acid N,ammonium N and amino sugar N,improved and enhanced the level of soil N supply. During the process of organic nitrogen accumulation,chemical fertilizer N mainly got into soil ammonium N and amino acid N pools,while organic fertilizer N mainly got into soil amino acid N pool.