Depletion of nutrients in adjacent crop lands by Eucalyptus camaldulensis

Abstract

Fine root distribution of Eucalyptus camaldulensis Dehnh and effects on soil fertility attributes were studied under field conditions in Badessa, Eastern Ethiopia. Soil samples were collected from inside the stand, edge of the stand and 10 m away from the stand at two depths viz., surface (0–15 cm) and subsurface (30–45 cm) and analysed for fine root biomass and nutrients. Fine root biomasses (root length density (RLD) and root weight density (RWD)) from within the stand and away from the stand were similar. However, RLD and RWD in the surface soils were 50–70% and 28–75% higher than those in the immediate subsurface soils, respectively, at all distances. The organic carbon (C), total nitrogen (N), available phosphorus (P) and exchangeable potassium (K+) contents of surface and subsurface soils inside the stand were 28–60% and 23–32% higher than those away from the stand, respectively. Surface soils had significantly higher organic C, total N, available P and exchangeable K+ than subsurface soils due to deposition of leaf litter. E. camaldulensis improved soil nutrients and organic matter status below the trees due to leaf litter deposition, while areas adjacent to the stand that did not receive litter were depleted of nutrients by the extensive fine roots.