Leaf Composition and Yield Response of Corn in Relation to Quantity-Intensity Parameters for Potassium
1970
Koch, J. T. | Orchard, E. R. | Sumner, M. E.
Data obtained by the quantity-intensity (Q/I) technique were tested against field experimental results to assess the value of the Q/I approach for characterising the potassium (K) status of soils. Q/I data describe K status by relating the energy level or intensity (I) of K in the labile pool to the amount (Q) present. It was shown that in a leached ferrallitic soil (Oxisol), the pool of labile K is a good index of the amount available to corn (Zea mays L.). It is superior as a criterion to both the equilibrium activity ratio and exchangeable K. Potassium content of the leaf is related to the pool of labile K free to participate in the mechanisms by which K is supplied to roots. Critical values for K in the labile pool at the beginning of the growing season are proposed, below which K deficiency is likely to reduce corn yield.
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