The effect of certain potassium fertilizers on ammonification, nitrification, and crop production
1923
Vandecaveye, S.C.
Pot culture tests of the effects of applications of manure, lime, and certain potassium fertilizers to Carrington loam upon ammonification, nitrification, and crop production lead to the following conclusions: The application of manure and lime stimulated to a marked extent the ammonifying and nitrifying power of this soil, but manure alone caused a slight depression in ammonification. Potassium salts such as KCl, K2SO4 and kainit, resulted in large increases in nitrification, but exerted only little influence upon ammonification. The treatments which stimulated the ammonifying and nitrifying powers, also resulted in decided increases in citrate-soluble and water-soluble potassium, showing that there existed a definite relationship between bacterial activities and the citrate-soluble and water-soluble potassium. Potassium fertilizers did not show any effect on the citrate-soluble phosphorus, but manure applications did. The use of potassium fertilizers alone produced increased yields in the wheat crop, but no appreciable increases in the clover crops. Kainit seemed to exert a toxic effect upon clover. Decaying organic matter and bacterial activities either separately or combined exerted a striking influence on the liberation of potassium.
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