SOME PHYSICAL AND CHEMICAL PROPERTIES AND STATUS OF NUTRIENTS AS AFFECTED BY SLOPE POSITION IN MARSA-MATRUH

Abstract

The current study aims to study some soil physical and chemical properties and available nutrient content in relation to soil erosion. Five soil profiles were dug in Wadi-Madwar in Marsa Matruh. The name of soil profiles were represented (South Wadi-Madwar, Soil stone, Bir Haiyub,Elshiyab cemeter and El Qasr ). Soil profiles along the main slope inside Wadi-Madwar reflect the effect of water erosion process on soil properties with slope 122-4mm. The results can be summarized as follows:- Particle size distribution and soil texture class for soil profiles revealed that silt and clay fractions were gradually increased down slope and soil texture of Wadi-Madwar were sand, sandy loam and loamy sand. Values of gravel percentage were decreased with down slope. The changes in pore size distribution due to soil erosion were identical and revealed that values of slowly drainable pores (SDP) in the soil profiles under investigation were very small. Water holding pores (WHP) and fine capillary pores (FCP) values were increased with increasing the slope length to the sea direction. Field capacity (FC) and wilting point (WP) values in the soil profiles under study increased with slope length toward the sea and Hydraulic conductivity (K) values decreased down slope toward the sea. Soil bulk density value in the deep layer was slightly higher than of the surface layer, at the same time, soil bulk density values were higher beside the mountain and decreased gradually with slope length towards the sea. Total porosity values decreased in all profiles beside the mountain and increased with down slope. Soil pH values of all soil profiles ranged between 8.1 and 8.9 and reflect the alkalinity of studied profiles. EC values were low and decreased with increasing soil depth and ranged between 3.1 and 6.9. Average content of calcium carbonate tends to increase with soil depth and at the down slope. Organic matter content tends to increase with soil depth and at the down slope. Cation exchange capacity (CEC) was mainly correlated with the soil fine fraction content and it was increased at down slope. The contents of available N, P, K, Fe, Mn, Zn and Cu increased towards the down slope area.