东北地区滨海盐渍土型稻田土壤有机氮组分的研究

用Bremner法测定东北地区滨海盐渍土型开垦5年、30年稻田土壤和邻近未开垦稻田的旱地土壤的有机氮各组分含量。结果表明:(1)在0~60 cm土层,3种土壤非酸解性全氮含量及其占全氮比率明显大于酸解性全氮,但总体上以表层土壤(0~20 cm)为最高。(2)与未开垦旱地土壤相比,种稻5年和30年均使表层土壤酸解全氮含量明显下降,但种稻5年使土壤酸解氨基酸态氮和氨基糖态氮的含量及其占全氮比率明显增加,使氨态氮和未知态氮的含量及其占全氮比率明显下降;而种稻30年则均使土壤酸解各组分氮含量及其占全氮比率明显下降。(3)与未开垦旱地土壤相比,种稻5年和30年稻田土壤酸解全氮含量及其占全氮比率均随土层深度的增加而逐渐降低,但2种稻田土壤酸解各组分氮含量及其占全氮比率的剖面分布则无明显的变化规律。

Studies on Organic Nitrogen Forms of Coastal Saline Paddy Soil in Northeast China

The contents of different organic nitrogen(N) forms were determined with Bremner Method in coastal saline paddy soil(paddy soil of 5 and 30 years rice cultivation and non-reclaimed upland soil).The results indicated:(1) The contents of non-acid hydrolysable total N and its proportion to total N of three soils were obviously higher than acid hydrolysable total N through out 0-60 cm soil layer,and the highest values were obtained in 0-20 soil layer.(2) Compared with the non-reclaimed upland soil,the content of soil acid hydrolysable total N significantly decreased all for paddy soil of 5 and 30 years.The contents of acid hydrolysable amino acid N,amino sugar N and its proportion to total N significantly increased,and the contents of acid hydrolysable ammonia N,unknown N and its proportion to total N significantly decreased for paddy soil of 5 year.And then the contents of acid hydrolysable N forms and its proportion to total N significantly decreased in paddy soil of 30 year.(3)Compared with the non-reclaimed upland soil,the profile distribution of soil acid hydrolysable total N forms and its proportion to total N has been greatly changed,which the profile distribution of soil acid hydrolysable total N forms and its proportion to total N had same rule for two paddy soils,namely,the contents were decreased with layers depth increasing,but the form of soil acid hydrolysable N and its proportion had no obvious regulation for two paddy soils.