Do you know how much nitrogen is available in your cornfield? Do you know how much fertilizer your cornfield needs this year? Most farmers will answer with an educated guess, but why guess when copy yields can be affected.

The most accurate means available to answer these questions is soil sampling. A soil test taken in March will accurately estimate the amount of P (phosphorous) and K (potassium) levels in the soil. This report will also recommend an application rate for nitrogen based on the amount of manure applied and expected crop yield. Unfortunately, this report does not give concentrations of N (nitrogen) in the soil as it does for P and K. This is because the methods used in sampling and testing soil for N are different then those used for P and K.

Soils should be tested for N as close to time of uptake as possible. For N testing in cornfields, one test available is the Pre-Sidedress Nitrogen Test (PSNT). A soil sample is taken from a cornfield when the corn is approximately twelve inches tall. Once the soil sample(s) are taken the results provide farmers with a means of rapid soil nitrate analysis. This analysis can be used to provide more accurate N fertilizer recommendations for their corn. These results can also give farmers a better idea of how much nitrogen is available from previous manure applications, and can be helpful when developing a manure management plan.

As a service to Cumberland County farmers, the Conservation District is offering this test free of charge. The staff will assist in sample collection, and will run the test. The results from the PSNT will be available within one or two days of sampling. If the PSNT sounds interesting to you, please contact Cumberland County Conservation District at 717-240-7812 to make arrangements to have your cornfields tested.