Soil respiration and microbial biomass peculiarities as influenced by different land use intensity

Abstract

In agroecosystems, it is important to maintain the soil agroecological potential and its productivity, which depend on soil organic carbon (SOC), biological activity and microbial biomass ensuring soil ecological functions. The aim of this study was to evaluate the soil microbial respiration and biomass in a Bathygleyic Distric Glossic Retisol of different land use intensity. These soil properties were measured in 0–10 and 10–20 cm mineral soil layers of the plough horizon in the biotopes of long-term different use: 1) arable land (>70 years cereal crop rotation), 2) temporary grassland (>70 years cereal crop rotation with temporary grassland), 3) perennial grassland (with 15–20 years of semi-natural grassland) and 4) silver birch stand (with 25 years old naturally regenerated forest stand in former agricultural land). In the study, the most intensive soil respiration was determined in the perennial grassland, silver birch stand and temporary grassland in the moderately acidic (pHKCl 5.0) soil. The concentrations of soil microbial biomass carbon (SMBC) and soil microbial biomass nitrogen (SMBN) were the highest in the silver birch stand, and the lowest concentrations were found in the arable land. In most cases, the activity of soil microorganisms (microbial respiration, SMBC and SMBN) was influenced by SOC, water soluble organic carbon (WSOC), humus and its fraction composition, and soil acidity. Despite this, the study did not show strong correlations between these properties. However, in a long-term perspective of soil use, the conversion of arable land to perennial grasslands or forest plantations can stabilize soil microbial activity due to persistent supply of organic matter.