Fertilizer Input Costs: Perceptions and Strategies.

Surveys of producers attending Extension meetings in February 2009 indicated that their top economic concern is rising fertilizer prices. Two common responses to this concern were to start using precision or variable-rate nutrient application and to start using nutrient placement. Spreadsheets on the economics of these two practices for P and K management were developed. A ‘front page’ with a dial indicator was developed that shows profitability of these practices relative to conventional broadcast management. This ‘front page’ also has a number of inputs that can be modified by the user, including fertilizer and commodity prices. Our analysis suggests that precision P and K management is profitable at current prices if soil test target values are reduced when using this practice (as supported by recent response data). It also suggests that subsurface placement of P and K will rarely be profitable even with low-testing rented land. Precision application of N using crop sensors has been profitable in 55 on-farm demonstrations in Missouri. Judicious use of precision agriculture technologies has the potential to reduce fertilizer input costs without reducing yield.