Effects of lime and water content on soil respiration

Abstract

This study investigated the effect of liming on soil respiration. Naike clay loam soil samples were taken from an area to which lime had been applied at 3 t ha-1and from an adjacent unlimed area. The effect of slow drying and 2 rewetting events on soil respiration was determined using gas chromatography. Water potential was determined using either thermocouple hygrometry or interpolation from gravimetric water content. The change in gravimetric water content was measured by change in mass of the flasks plus contents. The effect of substrate depletion on microbial activity was examined by keeping samples of unlimed soil moist throughout the 100-day experiment. he microbial activity in the limed soil may be accounted for by its increased water content compared to the unlimed soil at the same water potential. For soil which was kept moist, microbial activity (A) decreased with time (t) in the following manner.For soil which was dried gradually, the following relationship was found between soil respiration and gravimetric water content (w).On rewetting, soil respiration responded rapidly, and our results fitted relationships found in other studies. © 1985 Taylor & Francis Group, LLC.