Properly credit nitrogen contributions for the first and second years. Irrigation Water Application Irrigation water can be a valuable source of nitrogen for crops. The amount of nitrogen available depends on the nitrate concentration in the water and the amount of irrigation water you apply. In order to take credit for this component, you must have the irrigation water analyzed for nitrates and estimate how much irrigation water will be applied during the growing season. Manage Commercial Fertilizer Use The rate, form, placement, timing, and method of commercial fertilizer application can affect ground water quality.
Commercial fertilizer is the easiest component to manipulate and offers the most potential savings.
To get maximum benefit from the dollars you spend on commercial fertilizer, do not apply it on coarse-textured soils in the fall or before planting. Apply commercial fertilizer for crop utilization, not crop removal. Split the fertilizer amount needed into two or more applications for maximum crop utilization of nutrients. Use fertilizers that are in a stable form. Use a nitrification inhibitor with early sidedress nitrogen applications.