title: Changes in soil microbial biomass and aggregate stability under different land uses in the northeastern Turkey.
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.
authors: Department of Forest Engineering, Faculty of Forestry, Karadeniz Technical University, 61080, Trabzon, Turkey, okara@ktu.edu.tr.
authors: O
authors: O
authors: Kara
authors: M
authors: M
authors: Baykara
mesh_terms: D000383:Agriculture; D018533:Biomass; D004784:Environmental Monitoring; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D014197:Trees; D014421:Turkey
chemical_list: D012987:Soil