Effects of Ziziphus Spina-Christi (L.) on Selected Soil Properties and Sorghum Yield in Habru District, North Wollo, Ethiopia

Abstract

Ziziphus spina-christi is a multipurpose tree which grows naturally on the farm lands in Habru district. Since, the effects of this tree on soil and crop have not scientifically quantified; this study has been carried out with the aim of assessing the effect of Ziziphus spina-christi on soil physicochemical properties, grain and biomass yield of sorghum.Five isolated and nearly identical Ziziphus spina-christi tree growing on farm lands with similar site condition were selected and canopy coverage of each tree was divided into four radial transects. Soil samples from three horizontal distances: 1.2m, 2.9m and 15m with two soil depths (0–15cm and 15-30cm) were taken for analysis of soil physico- chemical properties. Three quadrates 1m x1m at each transect and distances were laid for sorghum grain yield and biomass estimation. The result shows that soil pH, EC, CEC and soil texture were not significantly (p>0.05) influenced by Ziziphus spina-christi tree, whereas soil bulk density, soil moisture content, total nitrogen, organic carbon, available phosphorus and exchangeable cation (Mg, Ca and K) were significantly (P<0.05) influenced mainly due to higher organic matter input through litter fall, root biomass, uptake and return of nutrients from deeper soil profiles under the tree canopies. While the grain yield of sorghum and above ground biomass were not statistically significant (p>0.05).Hence, retaining of this tree on crop land improves the soil fertility status.