Volatilization and Corn Yield Response to a Urease Inhibitor Under Tillage.

Abstract

                Urease inhibitors are often used with urea fertilizers when surface applied to prevent volatilization.  With minimal rainfall, it is suspected that a light tillage incorporation of urea may actually have greater volatilization losses than a deeper incorporation or even a surface application due to soil moisture.  This study measures the loss of nitrogen by volatilization with ammonia traps and corn yield as affected by urea with and without a urease inhibitor (NBPT-NPPT, Limus®) and under a surface application, a light tillage incorporation, and a medium tillage incorporation. The ammonia traps consist of a PVC collar with a suspended polyethylene foam pad soaked in an 11.45% phosphoric acid and 4.55% glycerol solution. The ammonia traps will be sampled at 5, 10, 20, and 30 days after treatment. This research will help inform farmers and potentially provide a cost savings by determining when to use a urease inhibitor and how to incorporate the urea to help minimize nitrogen loss due to volatilization to prevent yield loss.