Corn production budgets: Minding your P’s & K’s
Their bottom line—which can make a difference in the amount of P and K that is applied for the next crop—is: “There was large variation in the P and K concentrations and amounts in cornstalks across the sites, but mainly from the black layer stage to late fall. This high variation resulted from differences in soil-test levels, fertilizer rates, hybrids, rainfall and other growth conditions.” The agronomists add, “Nutrient loss between the black layer and harvest was large for both P and K, loss from cornstalks between harvest and late fall were large only for K, and the overall proportional loss by spring was greater for K.” However, they are quick to add that variations can be great from year to year and the best way to get a good idea of how much P & K are being removed from the field is to sample the cornstalks that are being removed.
Since cornstalks are considered a valuable organic fertilizer that is returned to the soil, there is little doubt that removal of the stover will reduce the available nutrients available for the next crop. But timing of that process can have a great impact on the added expense of replacing the nutrient or saving on the amount of fertilizer that has to be applied.
Source: FarmGate blog