The nitrogen fertilizer has a critical role in the plant growth and development processes by which the plant derives nitrogen which is in one content of cells. As a key element in the formation of many compounds whereas the most important are amino acids that compose the protein. Therefore, Nitrogen considers as important for growth and plant development and consequently for the increased outcomes. The Forage grass plants respond well to nitrogen fertilization and collect about half of the nitrogen absorbed by the plant during various stages of plant grains growth. Nitrogen positively affects the photosynthesis rate by increasing the rate of chlorophyll amount in the leaves, as it is the main element in the increase and composition of the dry matter of the plant, the size and capacity of the grin, and the final crops of grains as each ton of grain crops such as maize contain about 16 kg of nitrogen.