2.2.1. Soil sampling and analysis

Ten soil samples were taken from each sampling plot at 0–20cm depth in a zigzag fashion using an Auger (Nunez et al., 2011). The samples were physically mixed to get a 2 kg composite soil sample and air-dried to a constant weight. Finally, the samples were ground and sieved to 2 mm before chemical analysis. Soil physical and chemical analysis was conducted at Horticoop Ethiopia (Horticultural) Private Limited Company following the standard analysis methods. Total nitrogen was obtained using the Kjeldahl procedure. The Walkley and Black method was used to obtain organic carbon. Except for the above-mentioned properties, the remaining macro (available Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium (Mg), Sulphur (S)) and micronutrients (Iron (Fe), Manganese (Mn), Copper (Cu), Zinc (Zn), Boron (B), Molybdenum (Mo), Sodium (Na), Cobalt (Co), and Silicon (Si)) were obtained using the Mehlich 3 method. It is a weak acid soil extraction procedure designed to determine macro and micronutrients (Mehlich, 1984). In addition, soil pH was determined following the ES ISO 10390: 2014 (1:2.5-soil to water ratio) method (ISO, 2014). The soil textural classes were determined based on the Bouyoucos Hydrometer Method (Beretta et al., 2014).