ABSTRACT

CURRENT MANAGEMENT OF NITROGEN IN CROPPING SYSTEMS Production at Low Cost with Desired Quality By understanding the effects of nitrogen nutrition on harvested parts of crops, especially their quality, produce is improved. The digestible nitrogen content of forage, the protein content of cereal grains, the alpha-amine nitrogen of roots of sugar beet and the nitrate content of lettuce leaves are criteria directly related to nitrate metabolism. In some instances, the goal for high productivity is difficult to reconcile with obtaining the resultant quality; a high nitrogen nutrition, favourable for growth and productivity, can result in very high nitrate concentration in lettuce leaves, and in high protein content in barley, which is not compatible with use in the malt industry. Understanding and prediction of the relationship between nitrogen assimilation, floral differentiation, grain set and filling, and senescence, or understanding and prediction of the fate of nitrogen within the plant (protein synthesis, nitrate accumulation, proteolysis, allocation to various parts) in relation to the kinetics of absorption, are basic essentials for gaining control over production.