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土壤全氮量可作为判断土壤潜在肥力的一个重要指标,含量一般在0.02—0.5％,是土壤常规分析项目之一。土壤中氮素的形态可分为无机态和有机态两类。有机态氮占全氮的95％,只有在微生物的活动下逐渐矿化后,才能被植物利用;无机态氮仅占全氮的5％,能被植物直接吸收利用。土壤全氮测定方法较多,多年来一直采用开氏法。此法缺点消化费时,还要用混合催化剂。近年来我们应用了重铬酸钾—硫酸消化法,分析结果与开氏法比较,差异不
Soil total nitrogen can be used as an important indicator to determine the potential soil fertility, the content is generally 0.02-0.5%, is one of the soil routine analysis project. Soil nitrogen forms can be divided into inorganic and organic two categories. Organic nitrogen accounts for 95% of total nitrogen, and can be used by plants only after mineralization under the action of microorganisms. Inorganic nitrogen accounts for only 5% of total nitrogen and can be directly absorbed and utilized by plants. Determination of soil total nitrogen more, has been using the Kelvin method over the years. Disadvantages of this method digestion time, but also with a mixed catalyst. In recent years, we applied potassium dichromate - sulfuric acid digestion method, the analysis results compared with the Kaiser method, the difference is not