长期施肥对太湖地区黄泥土有机氮和有机碳的影响

Effects of Long-Term Fertilization on Soil Organic Nitrogen Forms and Organic Carbon in Paddy Soil in the Tai Lake Region in China

采用Bremner法对24年长期施肥试验后黄泥土耕层土壤有机N组成进行分级。结果表明:与不施肥处理相比,施有机肥能显著增加耕层土壤全N、酸解有机N、酸解NH4+-N、氨基酸态N、非酸解有机N和有机C含量,尤其利于提高氨基酸态N和非酸解有机N的含量;与不施N相比,施N肥能提高全N、酸解有机N、酸解未知态N、氨基糖态N和有机C含量。土壤有机N主要由酸解NH4+-N和氨基酸态N组成,其次为酸解未知态N和非酸解有机N,氨基糖态N含量最小。有机肥和N肥是影响全N、有机N、有机C和水稻产量的重要因子,两者配施能提高土壤供N和固C能力,是维持土壤肥力最佳的施肥方式。

To analyze changes in N supply capacity and organic C （OC） in paddy soil in the Tai Lake region in China after 24 years of fertilization, the Bremner method was employed for fractionation of soil organic N. Application of manure or manure plus mineral fertilizer significantly increased contents of total nitrogen （TN）, hydrolysable organic N （THN）, ammonium N （AN）, amino acid N （AAN）, non-hydrolysable N （NHN） and OC, especially AAN and NHN, in the soil as compared with CK （no fertilizer）. Application of fertilizer N increased contents ofTN, THN, unidentified hydrolysable N （HUN）, amino sugar N （ASN） and OC in the soil. Soil Organic N was mainly made up of AN and AAN, which were followed by HUN and NHN, with the content of ASN being the smallest. Manure and inorganic N fertilizer were important factors that influenced soil TN, soil organic N and crop yields. Based on the findings, rational application of organic manure and inorganic N fertilizer together might be thought to be an optimal way for sustaining soil fertility.