Avoiding soil degradation and improving crop productivity could be achieved by performing sustainable soil nutrient management with an appropriate understanding of soil properties’ spatial variability. The present fertilizer recommendations for the region where the study area is located are typically symmetric for large regions. This leads to the under-application of fertilizers in zones with low nutrient contents and over-application in zones with high nutrient contents. Therefore, this study was conducted to assess soil management zones (MZs) in the study area for effective soil nutrient management and to evaluate soil properties’ spatial variability. A total of 100 geo-referenced soil samples were collected at a depth of 0–20 cm, processed and analyzed for pH, available nitrogen (AN), available phosphorus (AP), available potassium (AK), soil organic carbon (SOC), total nitrogen (TN) and total phosphorous (TP), while C:N, C:P and N:P ratios were calculated. Soil properties’ coefficients of variation (CVs) widely varied from low (1.132%) to moderate (45.748%). Ordinary kriging and semi-variogram analysis showed differed spatial variability patterns for the studied soil properties with spatial dependence ranged from weak to strong. MZs were delineated by performing principal component analysis (PCA) and fuzzy K-means clustering. Four PCs with eigen values more than 1 dominated 84.44% of the total variance, so they were retained for clustering analysis. Three MZs were delineated based on the two criteria modified partition entropy (MPE) and fuzzy performance index (FPI). The studied soil properties differed significantly among MZs. Thus, the methodology used for MZ delineation could be used effectively for soil site-specific nutrient management for avoiding soil degradation concurrently with maximizing crop production in the study area.

In the light of water scarcity and high population growth of Egypt, there is an urgent need to exploit and reuse every drop of water. Remediation of the available marginal water resources such as drainage water for irrigation purposes became mandatory. A laboratory experiment was conducted at Soil Science Department Laboratory, Faculty of Agriculture, ZagazigUniversityduring 2021 to find effective and low-cost ways of wastewater remediation to be easily available. For that, the water samples were synthetically contaminated with two heavy metals, namely nickel and lead which were added in concentrations of 10mg/l and 0.5 mg/l, respectively. Four natural materialsi.e, moringa seeds cake (M), rice straw biochar (B), sugarcane bagasse biochar (S) and zeolite (Z)were used in this investigation to study their potentiality on removing lead and nickel from polluted water. All materials were used at two rates of 10 and 20g/l. Four different particle diameters were used for each of rice straw biochar, bagasse biochar and zeolite as follows:< 0.125 mm, 0.125 – 0.212 mm, 0.212 – 0.250 mm and > 0.250 mm. All materials used gave considerable efficiencies in removing lead and nickel ions from polluted water showing an inverse proportional efficiency with particle diameters. The rate of 20g/l surpassed the rate of 10 g/l for all treatments under the same diameter. The most efficient treatment for removing lead was sugarcane bagasse biochar at rate of 20g/l and particles diameter less than 0.125 mm with a removal efficiency of 90.39 % whereas the most efficient treatment for removing nickel was rice straw biochar at rate of 20g/l and diameter of particles less than 0.125mm with removal efficiency of 81.6%. The removal efficiency of lead for the investigated natural materials could follow the order: sugarcane biochar> rice straw biochar>moringa seeds cake>zeoliteswhile the order wasrice straw biochar>sugarcane bagasse biochar>moringa seeds cake> zeolites for nickel