The alkaline permanganate N. and the organic carbon N are the two estimations of N which are widely used for assessing the soil fertility for evaluating recommendations based on soil tests. The soil testing laboratories in India use either one of the methods as both are suited for rapid analysis. The alkaline permanganate releases N from easily hydrolysable fraction of organic matter which is reported to constitute about 10-12 percent of total N (Fraser, 1955). This, therefore, represents available fraction by mineralization during the crop growth phase. The organic carbon, on the other hand, represents total N universally.
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