Contribution of on-farm avocado (Persea americana) tree-based agroforestry practice on selected soil physical and chemical properties of Inguti small watershed, in the highlands of North-Western Ethiopia

Abstract

Agroforestry has a significant contribution to soil fertility enhancement as productive and protective value. Particularly, fruit tree-based agroforestry practice plays a significant role in improving productivity as well as soil fertility management. This study aimed to determine the contribution of on-farm avocado fruit tree-based agroforestry practice on selected soil physicochemical properties in the case of Inguti small watershed. Field survey and laboratory analyses were carried out based on selected physicochemical properties. Soil samples were taken from 12 sample avocado trees at 3 radial distances (under, near, and far from tree canopy) and two depths (0–20 cm and 20–40 cm) in four directions. Soil composite samples were taken for laboratory analysis. To investigate its contribution to selected soil’s physicochemical properties texture, bulk density, organic matter and carbon, pH, total nitrogen, available phosphorus, and available potassium were considered and the significant variation among treatments were analyzed. Based on the result of the study, except soil texture and soil pH, all other investigated soil physical (bulk density) and chemical properties (organic matter, organic carbon, total nitrogen, available phosphorus and potassium) were significantly varied for distance from avocado tree and soil depth from the surface with a p-value of bulk density P < 0.000 and 0.001), organic matter (P < 0.000 and 0.005), organic carbon (P < 0.000 and 0.006), pH (P < 0.00 and 0.626ns), total nitrogen (P < 0.000 and 0.006), available phosphorus (P < 0.002 and 0.01) and potassium (P < 0.002 and 0.01) for distance and depth respectively. So, on-farm avocado (Persea americana) has a significant contribution to soil physicochemical properties in the study watershed.