Balanced fertilization of major crops in egypt : a review

The aim of this study will be to have the ratio of nitrogen fertilizers applied to the main crops, using various sources of nitrogen, time and method of application, in order to increase the efficiency of nitrogen fertilizers and nitrogen to reduce losses. Most of the soil cultivated in clay, Egypt is alluvial soils in texture. About 420 thousand hectares, sandy and limestone. The results of the average physical and chemical analyses of the soil and samples from different sites to represent the different types of soils. The results obtained indicate the presence of a wide range of physical and chemical properties. The organic matter content is low and, accordingly, is the total nitrogen concentration. With regard to alluvial soils and available phosphorous determined by the Olsen method is generally moderate. The results indicate that available (soluble and exchangeable) potassium extract with a neutral solution of high ammonium acetate, this is a characteristic of alluvial soils of most Egyptians. Available levels of phosphorous, potassium, and micronutrients are relatively low on limestone and sandy soils.