Extension of the Pre - Sidedress Soil Nitrate Test for New Jersey Field and Sweet Corn Growers

Extension of the Pre - Sidedress Soil Nitrate Test for New Jersey Field and Sweet Corn Growers

Summary

Our main objective is to extend the use of the Pre-sidedress Soil Nitrate Test (PSNT) to New Jersey field and sweet corn growers. The PSNT is an in-season soil test developed by Fred Magdoff at the University of Vermont that provides information about the nitrogen supplying capacity of a soil. PSNT results may indicate that an adequate supply of nitrogen is available in the soil to meet the needs of the corn crop or that a supplemental application of nitrogen fertilizer is required. This information helps farmers make better decisions about how much nitrogen fertilizer to use. The PSNT is most useful on manured fields where adequate nitrogen is available and nitrogen fertilizer use can be reduced substantially.

The PSNT is currently being recommended for use on field corn, but further research is needed before it can be recommended for use with sweet corn. The research and Extension activities supported by this grant, along with support provided by the New Jersey Agricultural Experiment Station, has facilitated the adoption of the PSNT by at least 30 New Jersey farmers. Experience among dairy farmers, the primary users of the PSNT, has shown that nitrogen fertilizer use can be reduced by an average of 50 pounds of nitrogen per acre while still maintaining crop yield. When nitrogen fertilizer rates can be reduced without loss of crop yield, there is a reduction in cost for fertilizer and less risk of nitrate pollution of water supplies. Total statewide savings to New Jersey farmers and the environment as a result of adoption of the PSNT are estimated at $53,000 and 177,000 pounds of nitrogen fertilizer not applied to farmland.