摘要
采用长期定位研究方法,探讨了长期耕作与施肥对白浆土有机氮组分的影响。结果表明,白浆土耕层全氮含量为1840.8mg·kg-1。其中,非酸解总氮占土壤全氮29.8%,其余为酸解氮。酸解氮4种组分含量高低顺序为,未知态氮>氨基酸态氮>酰胺态氮>氨基糖态氮。有机肥极大提高了土壤酸解总氮及其各组分含量(除酰胺态氮),化肥则以增加酰胺态氮为主,秸秆还田土壤酸解总氮及其各组分也有一定增加,长期不施肥土壤有机氮库处于严重消耗状态。土壤酸解总氮各组分对氮素营养贡献大小为,氨基酸态氮>酰胺态氮>未知态氮>氨基糖态氮。长期施入土壤中的化学氮素,主要向酰胺态氮转化,秸秆还田中氮向氨基糖态氮转化最多,有机肥中氮向氨基酸态氮转化率最大。长期免耕,不利于植物对氮素吸收以及有机态氮矿化,致使其比普翻和深松更有利于土壤有机氮各组分的提高。
Effects of long term fertilization patterns （NP： chemical fertilizer, OM： organic fertilizer, TS： mulching straw, and CK： no fertilizer） on the speciation of organic nitrogen in albic soil were studied from 1992 to 2001. The crop rotation system used was winter wheat-winter wheat-soybean-canola-corn-soybean. The results also showed that the mean content of total nitrogen in albic sol was 1840.80 mg·kg^-1, among of which the non-hydrolizable nitrogen accounted for 29.8% and the rest was hydrolizable nitrogen in albic sol. And the 4 kinds of hydrolizable nitrogen were in the order： unidentified hydrolizable nitrogen 〉 amino acid nitrogen 〉 ammonium nitrogen 〉amino sugar nitrogen. In this 10-yr field experiment, NP, OM, TS application resulted in the increase of total hydrolizable nitrogen content in soil in different ways （NP, 1.8%; OM, 15.6%; TS, 7.0%）, while CK application caused the organic nitrogen pool was depleted during these 10 years （CK, -11.8%）. In NP treatment plot, most of the increase level of total hydrolizable nitrogen was ammonium nitrogen fraction （8.8%）, with unidentified hydrolizable nitrogen （0.9%）, amino acid nitrogen （-0.4%） and amino sugar nitrogen （-2.9%）. In OM treatment plot, it was amino sugar nitrogen （30.8%）, with amino acid nitrogen （23.4%）unidentified hydrolizable nitrogen （9.9%） and ammonium nitrogen fraction （3.6%）. In TS treatment plot, it was amino sugar nitrogen （17.7%）, with amino acid nitrogen （6.7%）, unidentified hydrolizable nitrogen （5.4%） and ammonium nitrogen fraction （3.4%）. Moreover, compared the plough-based tillage, conservation tillage （no-plough soil tillage） and no tillage effects on the speciation of organic nitrogen in albic soil, the highest organic nitrogen content in soil was measured in the no tillage treatment plot.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2005年第6期1127-1131,共5页
Journal of Agro-Environment Science
关键词
白浆土
有机氮组分
耕作
施肥
albic soil
form of organic nitrogen
tillage
fertilization
