Because soil tests for nitrogen are not entirely reliable, nitrogen application recommendations are based on yield goals. If your yield goals are overly optimistic, the recommended application rates for N will be high. The result: increased expense, increased levels of nitrogen in the soil, and increased risk to surface water and groundwater.

To set realistic yield goals, recognize that exceptionally good years are the exception. Establish realistic yield estimates for each field based on soil type, your own three- to five-year yield records, county average yields, and yields on neighboring farms. When figuring the average yield on a field, do not count years of abnormally low yields that resulted from weather-related conditions.