Changes in soil microbial biomass and aggregate stability under different land uses in the northeastern Turkey


KARA Ö., Baykara M.

ENVIRONMENTAL MONITORING AND ASSESSMENT, vol.186, no.6, pp.3801-3808, 2014 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 186 Issue: 6
  • Publication Date: 2014
  • Doi Number: 10.1007/s10661-014-3658-0
  • Title of Journal : ENVIRONMENTAL MONITORING AND ASSESSMENT
  • Page Numbers: pp.3801-3808
  • Keywords: Aggregate stability, Land use, Microbial biomass, Soil texture, ENZYME-ACTIVITIES, ORGANIC-MATTER, CARBON, FOREST, NITROGEN, QUALITY, REGION, CLAY, DEGRADATION, MANAGEMENT

Abstract

The characteristics of three neighboring soils from the NE of Turkey were evaluated in order to elucidate the effect of different land-use management on the soil aggregate stability and microbial biomass in Galyan-Atasu dam watershed. Three experimental sites corresponding to three land uses were selected. The first site is a hazelnut orchard (agriculture), the second site is a forest dominated by mature coniferous trees, and the third site is grassland. Soil aggregate stability values for the 1-2-mm aggregates increased from forest (lowest) to agriculture (highest) in the current study. The percentage of clay was highest in agriculture soils with 33.57 %, and overall stability values increased according to soil clay content. The lower aggregate stability in the forest soils probably reflects the highly silty texture soils with 11.95 % compared to agriculture and grassland. However, in our study, there were no significant correlations between aggregate stability and organic C concentrations either in cultivated or forested soils. Aggregate stability depended more on the organic matter content when the organic matter content was greater than 50 or 60 mg g(-1). Below that threshold, aggregate stability may be mainly related to clay content. Furthermore, the results confirmed that higher percentages of Cmic/Corg in agricultural soils are the result of more labile organic substrates maintained in the soil, allowing a higher microbial biomass C per unit of soil organic C. This work gives a better understanding of the relationships between land-use type and soil aggregation and allows to know the soil response to different types of management in humid environments.