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The Influence of Form and Fineness of Lime Compounds Upon the Correction of Acidity and Upon the Nutrient Status of Soils
Author(s) -
Beacher R. L.,
Merkle F. G.
Publication year - 1949
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1949.036159950013000c0071x
Subject(s) - fineness , lime , citation , soil water , mathematics , nutrient , computer science , chemistry , environmental science , library science , soil science , geology , organic chemistry , paleontology
THE functions which lime compounds perform in the amelioration of acid soil conditions depend upon the rates with which they dissolve. These rates depend upon the form, whether oxide, hydrate, or carbonate; the fineness of subdivision, especially in the case of raw limestones ; and finally, upon the density of the product. The relative content of calcium and magnesium likewise determines the relative speed of reaction. It has been customary for control laboratories to analyze for total CaO and MgO and to run a screen test. The combination of the percentage of total oxides and the screen test is supposed to determine the relative effectiveness of agricultural value. Considerable evidence has been obtained by numerous workers indicating that very fine grinding of raw limestone is essential for effectiveness. Vegetation experiments have shown that limestone which is finer than 100-mesh is equal to hydrated lime in promoting yields on acid soils. Material coarser than 20-mesh has such small surface area that it is very slow to react with the soil and has been found to remain almost unaltered for many months. Conclusive as the early experiments appear to be, there are some questions not adequately answered by them. Is fineness and chemical analysis sufficient to evaluate limestones or should the relative porosity, crystal form, content of magnesium, and possibly other properties be taken into account? The work here reported was an attempt to devise a procedure which might combine chemical analysis and physical form in a simple expression which might be called "relative effectiveness". To determine this so-called "relative effectiveness", we have the measurement of available or exchangeable nutrients as affected by different lime products added to the soil, and finally, of course, the influence upon the yield of some lime-loving plants.