Abstract:A project was carried out to study a basic EDTA method for measuring soil organic matter, and correlations of basic EDTA organic matter with Tyurin organic matter, and with plant N uptake, and application of the method in soil testing and nitrogen fertilizer recommendation. Lab analysis of 50 soil samples each for red soil, fluvo-aquic soil and black soil, typical of the soils in China revealed that basic EDTA organic matter was highly correlated with Tyurin organic matter, being 0.9345 (p>0.01) in correlation coefficient and forming a linear regression equation, i.e. Tyurin organic matter (g kg-1) = 3.3265* basic EDTA organic matter(g kg-1)+ 6.9389. Pot experiments using 28 major types of soils on N deficiency and plant N uptake indicated that basic EDTA organic matter was significantly correlated with plant N uptake, and its the correlation coefficient (R = 0.628,p>0.01)was higher than that of the correlation of Tyurin organic matter and soil total N with plant N uptake. Although the correlation coefficient between basic EDTA organic matter and plant N uptake of plant was not as high as that between soil mineral N after 2 weeks of aerobic incubation and plant N uptake, basic EDTA organic matter is extracted soil humic matter and can be fast determined with photometry. Therefore, the EDTA method for soil organic matter is a better means for estimating soil N supplying capacity and worth recommending to the laboratory for use in the soil testing and N fertilizer recommendation.