Effects of Liming on Grass Growth, Soil Solution Composition, and Microbial Activities

Abstract

Abstract In order to determine the effect of liming on grass growth, the chemical composition of the soil solution and microbial activities were analyzed. Ground limestone (CaCO3) was topdressed at the rates of 0, 2, 4, and 8 t/ha to a 9 year old orchardgrass sward. The effects of liming on the soil were observed only in the surface layer (0–5 cm) during the 6 month period after lime application. Although the yield of grass was not distinctly affected by Iiming, the amount of phosphorus (P) and calcium (Ca) absorbed by the grass was considerably increased. With increasing rates in lime application, the concentrations of Ca and sulfate (S), and the value of the pH in the soil solution (0–2 cm layer) were increased, while the concentrations of a1uminum (AI), P, and nitrogen (N) were decreased. No change was observed in the chemical composition of the soil solution from the layers below 5 cm. The microbial activities 2,3,5-triphenyltetrazoJium chloride (TTC)-reducing activity. fructose or urea-decomposing activity, and bacterial numbers) were increased by liming. Key Words: acidificationlimingsoil solutionmicrobial activities