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