INFILTRATION RATE AND ITS RELATION TO IRRIGATION SCHEDULE FOR WATER ERODED AREAS IN EL-MAGHARA LOCATION, SINAI, EGYPT

This study was carried out in El-Maghara Experimental Station of the Desert Research Center, Sinai. The purpose of this study was to investigate and evaluate the some soil physical and chemical properties, i.e. soil texture, soil infiltration rates, bulk density, available water and soil chemical properties of water eroded areas (runoff) and what are the best method for irrigation systems and the type of crops to be cultivated.
                The area under studies is divided into three zones along water direction, eroded zone, transport zone and depositional zone. The first zone (eroded zone) is about 600 m long and represented by four soil profiles (1, 2, 3 and 4) the distance between them is 200 m (the first soil profile at point zero, start of water erosion). The second zone (transport zone) is about 680 m long and represented by four soil profiles (5, 6, 7 and 8), the distance between them is 170 m from the end of eroded zone. The third zone (depositional zone) is about 450 m long and divided to three soil profiles (9, 10 and 11), the first of which starts about 150 m apart from the end of the second zone (transport zone).
                Results show that the values of infiltration rate vary from zone to zone and even within the same zone according to water direction. The values of infiltration rate at these zones range from 41.65 to 106.70 cm/hr, 23.62 to 30.60 cm/hr and 15.48 to 18.41 cm/hr for the 1 st, 2 nd, and 3 rd zones, respectively. All values of infiltration rate in the studied zones are very rapid and rapid. Also, the results point out that the gravel content is higher in the first zone than the second zone while being absent in the third zone. The percentage of fine fractions (silt, clay and silt plus clay) and concentrations of cations and anions increase along water direction, while the reverse is true with sand.
                The data showed that the irrigation frequencies can be predicted for different crops according to soil infiltration rate, available water and soil texture.