Monday, November 13, 2006 - 2:30 PM
97-5

Agricultural Management of Enhanced Efficiency Fertilizers: South.

Gregory Schwab, Univ Kentucky, Dept of Agronomy, N122T Ag Sci Bldg North, Lexington, KY 40546, Lloyd Murdock, Univ Kentucky, PO Box 469, Princeton, KY 42445, and Stephen Ebelhar, Dixon Springs Agric. Res. Cnt., Simpson, IL 62985.

Enhanced efficiency fertilizers have historically been used in the Southeastern U.S. for high value horticultural, vegetable and turf crops.  However, increasing fertilizer expenses and relatively stagnate commodity prices are causing producers to consider these technologies for agricultural crops.  The farmers' goals are to improve fertilizer use efficiency and reduce the overall need for fertilizers, but the added cost must be offset by either an increase in yield or a reduction in overall fertilizer need.  Several commercially available products have been designed to improve efficiency by either preventing fertilizer loss or increasing uptake.  For nitrogen, urease and nitrification inhibitors have been used successfully for many years.  Recently, a low priced polymer coated urea (ESN®, Agrium Int.) with a release curve similar to N uptake in corn has been made available.  Research results show that corn and wheat yields can be increased as a result of using this product when soil conditions are favorable for both denitrification and volatilization losses.  For phosphorus, a high charge density polymer (Avail®, Specialty Fertilizer Products) has been show to reduce P fixation and increase yield of rice and soybeans.  Other products and application techniques such as foliar fertilizers have not demonstrated consistent economic benefits.  When used appropriately, enhanced efficiency fertilizer products can improve the profitability of production agriculture.