Wattle fencing improved soil aggregate stability, organic carbon stocks and biochemical quality by restoring highly eroded mountain region soil

Eroded bare land stabilization is important to reduce soil erosion and stimulate soil carbon (C) sequestration for improved soil biogeochemical quality in hillslope soils. This study investigated the effectiveness of wattle fencing as a bioengineering tool to improve soil stabilization, soil physico-chemical properties and soil organic C dynamics and reduce soil erodibility in the Boyabat mountain regions of Turkey with rough and over-steepened slope (50-70%). Wattle fence treatments were developed in the area of 50 ha in the spring season of 2010 and surface (0-20 cm) and subsurface soil (20-40 cm) samples were taken in Spring, 2015. Results revealed that, compared to control with bare slope, wattle fencing significantly improved some soil physico-chemical, and microbial properties and erodibility indices by increasing clay ratio, dispersion ratio and aggregate stability index in surface and subsoils. Wattle fencing enhanced plant available water contents more in surface than in subsoils. Wattle fencing also increased microbial biomass C contents by 55% and 43% in surface and subsurface soils, respectively. Soil organic C followed similar trends; however, they were indifferent between sampling depths for the control soils. Soil organic C stocks and aggregate stability index were significantly positively correlated and seemed to be better predictor of positive effects of wattle fencing on soil structural stability, erodibility and associated properties. We found positive effects of soil organic C contents on microbial biomass C and soil-water relations suggesting restoration of soil biological functions and favorable influence on soil water retention following wattle fencing. Although sparse vegetation was observed in the research area, our study emphasizes performing further research to understand the effects of wattle fencing along with afforestation with native vegetation on soil erosion rates on a long-term basis by considering the variability in edaphic and environmental factors.