长期施肥对菜田土壤有机氮组分的影响

试验以长期施肥为研究对象,采用Bremner提出的土壤有机氮分级方法对菜田土壤有机氮组分进行研究。结果表明,与不施肥(BN0)相比,单施化肥对菜田土壤有机氮含量和组分的影响较小。与单施化肥相比,有机肥与化肥配施能够显著提高菜田土壤全氮、酸解有机氮的含量,分别提高了19.7%和26.7%;在酸解氮中,其对氨基酸态氮和酸解未知态氮提高幅度分别为36.6%、32.1%,而对氨基糖态氮和氨态氮增幅较小。在不同肥料处理中,菜田土壤各种有机氮含量依次为:氨基酸态氮非酸解性氮酸解未知态氮氨态氮氨基糖态氮。长期有机无机肥配施使菜田土壤的供氮能力显著提高,也是维持菜田土壤肥力最适的施肥方式。

Effects of Long-term Fertilization on Soil Organic Nitrogen Fractions in Vegetable Soil

The long-term fertilization is taken as the research object in this trial, Organic nitrogen （N） forms in Vegetable-soil were quantified using the method proposed by Bremner. Result showed that compared with the control, neither single chemical fertilizer had the effect on the content of vegetable soil organic N, nor had the effect on the nitrogen composition. Compared with chemical fertilizes, manure plus N fertilizes greatly in- creased the contents of total N and acid hydrolysable N by 19.7% and 26.7% ;Of the forms of acid hydrolys- able N,which lead to the increase of amino acid N and hydrolysable unidentified N by 36.6% and 32.1% , while the increase of amino sugar and ammonia N is smaller. The contents of different forms of vegetable soil organic N in all treatments followed the order of amino acid N 〉 non-hydrolysable N 〉 unidentified hydrolysable N 〉 ammonia N 〉 amino sugar N. Manure plus chemical fertilizer increased the content of most organic N, and was considered the best method of maintaining the vegetable soil fertility.