【摘要】 <正> 碱化土壤是我国北方平原地区广泛分布的一种低产土壤,它的改良利用是提高该地区农业生产水平的重要措施之一。碱化土壤因其碱化程度不同,改良措施也不一样,因此,土壤碱化分级对生产有一定的意义。碱化土壤的分级,各国采用的标准是不一样的。目前国际上多数采用美国的标准,将更多还原

【Abstract】 The present paper deals with the subdivision of degree of soil alkalinization in Huang-Huai-Hai plain, the conclusions are summarized as follows:1. If the soil samples collected are typical and representative, the analytical data are reliable and variables selected （property indexes） are suitable, the application of "the analytical method of synthetic numerical value" in subdivision of degree of soil alkalinization may be realized satisfactorily.2. Based on the major items and specific indexes suggested by the authors, the alkalized soils in Huang-Huai-Hai plain are subdivided into 4 grades, namely, tile alkali soil, strongly alkalized soils, moderately alkalized soils and weakly alkalized soils. The standards for subdivision of the alkalized soils are given in tables 2. According to the equation P_g=sum from 1 to N （T₁W₁）+sum from to N （T₂W₂） the data in table 2 are computed, on the basis of Pg value, the grade of the alkalized soils can be distinguished. For the convenience of application in practice, the results calculated from the table 2 are simplified in table 3. Through the experiment of the effect exchangeable sodium percentage （ESP） on soil physical properties and the growth of wheat seedlings, the figures of indexes for subdivision of alkalized soils mentioned above are rectified.3. The residual sodium carbonate and ESP are suggested as the major indexes for subdivision of degree of soil alkalinization in Huang-Huai-Hai plain. Their important role in alkalinization process is discussed. The effect of else properties on subdivision of degree of soil alkalinization are in the following order: total alkalinity>exchangeable Na⁺>pH>Na⁺/(Ca⁺⁺+Mg⁺⁺)>exchangeablecapacity>total salt.更多还原