Importance of nitrogen in maize production

Among several functions, the nitrogen plays a key role on plants metabolism, this element takes part in different metabolic path ways of great importance to plants and participates in the protein synthesis. Most of the cultivated soils allow plants growth without addition of nutrients in mineral form. However, to seek higher production levels, the application of nutrients in mineral form is required, the current recommendation of nitrogen fertilization to define the amount to be applied. More than 95% of the nitrogen in the soil is organic, this organic form is not assimilated by plants, requiring to go through a mineralization process, in other words, the transformation from organic to mineral nitrogen called amination and ammonification. The identification of the character of highest contribution to maize yield is an important tool which assists identifying the critical period of the crop development, allowing the adoption of management practices in order to optimize the conditions at the moment of the main grain yield component definition. Generally, nitrogen is present in the soil solution on nitrate or ammonium forms, however the plants are physiologically responsive only to nitric nutrition, there were verified different responses among genetic materials regarding on nitrogen utilization efficiency