- The enhanced efficiency (EEF) products we tested in our study hold the potential to increase the nitrogen utilization efficiency of sweet corn as well as reduce nitrate leaching when all N fertilizer is applied before planting. However, this potential is limited by weather (i.e. large early season rainfall events), irrigation management, and soil conditions (i.e. sandy soils). In most years and at most sites these products will likely not increase yield. But, for early spring plantings on sandy soils, use of these products add extra insurance against nitrate loss in the event of large storm events occurring within 4 weeks after planting.