Basic Cation Saturation Ratios as a Basis for Fertilizing and Liming Agronomic Crops: I. Growth Chamber Studies1
- D. J. Eckert and
- E. O. McLean2
Basic cation saturation ratios are often used as a basis for making fertilizer and lime recommendations; however, little expermental evidence is available to support or refute the concept. This study was conducted to evaluate crop growth as influenced by varying soil cation ratios. A Loudonville silt loam (Ultic Hapludalf, fine loamy, mixed, mesic) was amended with K. and Mg to the following levels: 2.5 and 5% base saturation of K; 4, 8, and 16% Mg; and with Ca as Ca(OH)2 to pH 5, 6, and 7. The soil was then cropped with German millet (Setaria italica L. Beauv.) and alfalfa (Medicago saliva L.). Maximum yield of German millet was obtained at several soil K/Mg/Ca ratios. Yield increased as soil and plant Mg/Ca ratios increased, except where high soil Mg and low soil Ca levels induced Ca deficiency in the plants. Alfalfa also grew well at several ratios, particularly at the higher soil pH levels. The data indicated that balance of cations in the soil was unimportant, except at the extremely wide ratios where deficiencies of one element were caused by excesses of others. Hence, no best ratio existed for either or both crops.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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