Nitrogen is the major nutrient input on most crops, helping provide a low-cost, abundant food supply. It can move into surface or ground water and, at high concentrations, cause health problems for babies and livestock. While addressing best management practices for agricultural purposes, the same principles and some of the same practices also apply to non-agricultural uses.

Top 9 Best Management Practices for Nutrient Management

1. Set realistic yields.

For crops, use the actual yield records on the specific field. If desired, adjust for the expectation of a 5% or 10% yield increase. Do not fertilize for an unattainable yield goal.

Benefit: Limits potential for excess soil levels of nutrients.

2. Soil testing.

A general soil sample for testing should be taken down to a depth of 6 to 8 inches. For nitrogen, sample down to a depth of two feet and analyze separately to obtain an accurate profile nitrogen test.

Benefit: Results from the test combined with credits for previous crops and manure application can be used to prevent over-fertilization. An unknown deficiency of a critical nutrient may also be discovered.

3. Placement.

Placing nutrients close to the target crop and not uniformly distributing it over the field feeds the crop and not the weeds. Care must be taken to not exceed the maximum amount in the seed row itself as recommended by the crop specialist.

Benefit: Reduced application rates. Lower production cost. less nutrients with the ability to be lost by leaching or surface runoff.

4. Application timing.

Split applications of nitrogen on sandy soils or soils with shallow water tables to match crop needs. Nutrients like phosphors if applied too early for the target crop will have a higher percentage tied up by soil particles for the current growing season.

Benefit: Places nutrients in the soil when it is most likely to be taken up by the crop. Reduces chance of leaching and other losses.

5. Site specific management.

Rather than applying a single nutrient rate over the entire field, nutrient application rates should be varied depending on soil type and actual history of small areas within the field.

Benefit: Helps ensure that no area of a field receives more nutrients than necessary.

6. Nitrogen inhibitors.

There are products available to slow down the rate at which ammonium-nitrogen is converted into nitrates.

Benefit: Less nitrates are available to leach into groundwater.

7. Manure management.

Sample manure to know its nitrogen and phosphorus content. Then calibrate the manure spreader and apply only as much manure as the nutrient requirements of the crop. Incorporate after application. Do not apply to frozen ground. Be sure to account for the applied nutrients in the manure if additional commercial fertilizer application is planned so over-application does not result.

Benefit: Manure adds humus and improves the physical condition of soil as it relates to plant growth, (otherwise known as soil tilth). When planned carefully with other nutrient sources, runoff problems and the application of excess levels of nutrients can be avoided.

8. Careful handling and mixing practices.

Store, handle, and mix nutrients products away from wells and other water sources. Keep manure and livestock wastes at least 200 feet away from wells to prevent problems with direct run-in.

Benefit: Helps prevent accidental contamination of water supplies with large concentrations of nitrogen.

9. Buffer zones.

Create "off limit" zones around environmentally sensitive areas.

Benefit: Helps prevent contamination of water.

Mostly from Kansas State University Extension MF-2202 Best Management Practices for Nitrogen: Water Quality.