The effect of soil management systems on microbial activity

Abstract

The objective of this study was to evaluate basal (BR) and specific respirations (qCO2) of soils under native pasture and long-term cultivated soils at semiarid climate of the northern Turkey. In addition, the dependencies of BR to soil water content and the relationship between microbial biomass C (Cmic) and qCO2 were determined in the both ecosystems. Soil samples were collected from 0-5, 5-15, and 15-30 cm layers of native pasture and long-term cultivated soils. Soil microbial biomass was determined using fumigation incubation method. Specific respiration was calculated as BR/Cmic. BR varied through growth season in the both ecosystems and native pasture generally had greater BR than long-term cultivated soil. The highest BR was observed in October at native pasture. However, qCO2 was generally greater in long-term cultivated soil compared to native pasture. qCO2 and Cmic were negatively correlated at all layers of both management systems. There was not a significant dependency between soil water content and BR in Fluvaquentic Haplustolls. Thus, long-term cultivation increased qCO2 which varied through growth season. Soil organisms under stress condition increased qCO2 compared to native pasture.