Two farmers might be using the same amount of chemicals, but one is managing them better, says Lindsay. The bill is still the same. Lindsay is finding a monetary payoff in nitrogen. Last year, he wrote a nitrogen prescription based on three layers of information an Iowa State computerized soil survey layer referenced to a database, a soybean nitrogen credit layer and a manure application layer. From the database, he multiplied the realistic yield by 1.2 pounds of actual nitrogen to determine the nitrogen needed for each soil type.
Few farmers have first-hand knowledge of yield monitors.
Those who do are invaluable sources of information on such topics as cost, management, payoffs and advice. Next, he subtracted the soybean credit and the applied manure layers to determine the needed nitrogen. He transferred the prescription to the Vision System in his tractor and applied the needed nitrogen. The map on the right shows how much nitrogen he applied. In the areas where he only applied 38 pounds, he saved money without hurting yield.