Nitrogen is cheap and it is less costly to apply more N rather than investing in a variable rate application system. Why not continue to use pre-plant N?
Anhydrous ammonia is inexpensive, approximately $0.28/lb., and it is often considered appropriate to apply 100 lbs. of pre-plant N (wheat) and ignore the in season crop N needs. Pre-plant application of N is extremely inefficient (~33%). Prior to the 5 leaf stage, wheat’s N needs are small and high rate pre-plant application of N is potentially wasted because the crop will not use it. The unused portion of the N that remains in the soil is often lost before the crop is able to use it. This may result in N stress later in the growing season and, ultimately, yield losses. The amount of N supplied by the soil is not well understood and unpredictable. The organic fraction of soil is a huge reservoir of N. In fact, 1% organic matter contains about 2,000 lbs. of N per acre. If the organic fraction of N is mineralized and made plant available, the need for supplemental N is reduced or precluded. The GreenSeeker® saves unnecessary expense by applying the optimum amount of N for the soil condit
