Efficient nitrogen (N) fertilization is crucial for economic wheat production and protection of ground and surface waters. Excessive plant-available N produces wheat plants that are susceptible to lodging and disease with resulting decreased yields and increased input costs. The potential for enrichment of ground and surface waters with nitrates also increases with excessive N fertilizer applications.

Corn must have adequate amounts of nitrogen (N) and phosphorus (P) for profitable production. Nitrogen and phosphorus are also the nutrients that produce excessive algae growth in surface waters when concentrations increase above certain critical levels. Profitable and environmentally sensitive corn production requires that N and P be managed in an efficient manner. Economic returns from the use of these nutrients can be maximized, while the potential for surface and groundwater enrichment with N and P can be minimized with the use of appropriate technology. Available technology includes soil testing to evaluate residual soil nutrient supplies, and the use of proper application rates, methods, and timings.

Modern winter barley cultivars are capable of yields in excess of 170 bu/acre with relatively high test weight. Efficient nitrogen (N) fertilization is crucial for economic barley production and protection of ground and surface waters.