hydroxide, calcium carbonate, calcium-magnesium carbonate, and calcium silicate slags.
The beneficial effects of liming are often dramatic and produce striking increases in plant growth. The benefits of liming are attributed to (1) the value of calcium or magnesium as a plant nutrient, (2) the improvement of phosphorus availability, (3) enhanced decomposition of plant residues, and (4) increased availability of nitrogen for plant growth. Nitrogen fixation in legumes is enhanced, and soil physical condition is improved. The possible benefit of limestone as a source of CO2 has apparently not been recognized because it has not been mentioned in textbooks. The general reaction of limestone in acid soil is: