长期施肥对红壤性水稻土有机氮组分的影响

通过16年的田间定位试验，研究了长期不同施肥模式对红壤性水稻土有机氮组分的影响.结果表明：长期化肥处理对土壤各氮素含量的作用不明显；有机物料循环特别是有机肥和化肥配施显著提高了土壤矿质氮和有机氮含量，提高幅度分别为55.2%和38.8%.有机物料循环处理显著提高了酸解性氮组分，其对土壤铵态氮、氨基糖氮和未知氮含量的提高幅度分别为36.5%、68.4%和73.9%；有机物料与化肥配施后，氨基酸氮含量也显著提高，提高幅度达71.1%，但是降低了未知氮含量，降低幅度为34.5%.此外，各施肥处理土壤累积矿化氮量均随培养时间的延长呈增加趋势，有机物循环或配施化肥处理土壤矿化氮量均高于单施化肥处理.

Effects of long-term fertilization on soil organic nitrogen components in paddy soil derived from red earth

A 16-year long-term fertilization experiment was conducted on paddy soil derived from red earth to investigate the effects of different fertilization patterns on the concentrations of soil organic nitrogen (N) components. When chemical fertilizers were applied only, the soil nitrogen content was slightly infuenced. Organic fertilization, especially its combination with chemical fertilization, could significantly increase the contents of soil mineralizable N and organic nitrogen by 55.2% and 38.8%, respectively. In addition, organic fertilization could significantly improve the components of acid hydrolysable N, and lead to the increase of ammonium N (AN), amino sugar N (ASN), and hydrolysable unidentified N (HUN) by 36.5%, 68.4%, and 73.9%, respectively. When the organic fertilization was combined with chemical fertilization, soil amino acid N content was increased by 71.1%, while HUN content was decreased by 34.5%. In all fertilization treatments, the cumulative amount of soil mineralized N increased with increasing incubation time. The content of soil mineralized N under organic fertilization and its combination with chemical fertilization was higher than that under chemical fertilization.