Potassium (K) is one of the three major plant nutrients and most neglected by the farmers though it considered as equal as or sometimes more than the nitrogen requirement by the crops in many of the Indian soils. Though the potassium exist in different forms viz. water soluble and exchangeable K as available and non-exchangeable, fixed K and clay lattice K as slowly available to plants, the available K constitutes only 1-2 % of total K. In this circumstances, nutrient fixation study may give better idea to quantify the fertilizer to be added to crops. In this aspect I initiated K fixation study through adsorption isomers (Langmuir and Freunlich) for 5 different soils under Tamiraparani river command area. The data and graph pertaining to the K fixation study are enclosed for discussion. Please suggest me the amount of nutrient to be added to satisfy the K fixation.
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It does give ample idea about nutrient behavior under controlled conditions
but relating with field conditions , becones a formidable task to have reproducible results...
The quantitative description of the equilibrium data ((x/m)e vs ce) by means of selected isotherms, here Langmuir and Freundlich, enables the interpolation of data, and sometimes their extrapoation. The use of the Langmuir isotherm also makes it possible to calculate the value (x/m)max. And that's all. However, I would propose to determine R2, but also ARE for the original data (x/m)e vs ce and not non-linearly transformed..