Optimal Nitrogen Fertilizer Rates Given Current Fertilizer and Crop Prices

Given the recent increase in nitrogen prices, it is ever more important for producers to make management decisions that account for both input (fertilizer) and output (crop) prices in order to maximize profits. Historically, few Universities explicitly considered prices when making fertilizer recommendations. The cost of ignoring prices was low given nitrogen prices such as those observed from 1976-1994, however as nitrogen prices have increased, the cost of ignoring prices in fertilizer decisions has increased. This paper presents results from previous research where prices are incorporated into K-State’s official nitrogen fertilizer recommendations. The high crop prices forecasted for 2007 offset much of the impact of higher nitrogen prices, but irrigated producers still face high pumping costs which also need to be accounted for. Based on forecasts for nitrogen fertilizer prices and crop prices for the upcoming year, optimal nitrogen levels on dryland crops are generally 2 % to 5 % lower than official KSU recommendations. Reductions in optimal rates for irrigated crops are considerably higher, 10 % to 20%, due to the impact of higher pumping costs as well as the higher nitrogen costs. It is important that producers consider optimal nitrogen rates for their own situations as opposed to relying upon general recommendations so as to maximize return