Relationship Between the Potassium Removed by Millet and Red Clover and the Potassium Extracted by 4 Chemical Methods from 6 Kentucky Soils1
- Paul Sutton and
- W. A. Seay2
Six soils were cropped in the greenhouse with millet and Kenland red clover to determine the potassium-supplying power of the soils and the degree of correlation between the potassium removed by the crops and that extracted by four chemical methods. Potassium fertilizer was applied to determine the effect this would have on the potassium-supplying power.
Potassium was extracted from moist and air-dry soil samples with 0.15N H2SO4, 1.38N H2SO4, 1N NH4Ac and 1N HNO3. The potassium extracted from moist soil samples correlated better than did air-dry soil samples with the amount of potassium removed from the soils by millet. The potassium extracted by 1N NH4Ac and 1.38N H2SO4 from moist soil samples correlated better than did air-dry soil samples with the amount of potassium removed from the soils by clover. The differences in potassium extracted from moist and dry samples were small for the 0.15N H2SO4 and 1N NH4Ac methods.
The potassium extracted by 0.15N H2SO4 and 1N NH4Ac from air-dry soil samples and the potassium extracted by 1.38N H2SO4 from moist soils gave the best indexes for evaluating the potassium-supplying power of these soils.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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