It’s bad enough when heavy rains and saturated soils wash away your applied N investment. But you really compound the economic risk if you fail to replace it, says Jeff Vetsch of the University of Minnesota. Vetsch used a 5-year yield response to various rates of N study to estimate how much yield would be lost if 25, 50, 75 and 100% of the N was lost.

In his estimates, yields from fields with no N loss averaged 220 bu./acre. He figures that if 75% of the N was lost, in continuous corn, an estimated 35% yield loss would amount to 77 bushels and $462/acre! Even a much more moderate loss of 25% of N lost and not replaced in a continuous-corn field would result in an estimated 11-bu./acre loss at a cost of $66/acre.