A Nitrogen Recommendation Algorithm Utilizing Optical Sensors for Intensive Nitrogen Management of Winter Wheat.

Increasing yield has been the main interest of producers in Kansas.  However within the past decade researchers and producers have made extensive efforts to improve profit per acre without sacrificing yield potential.  Optical sensors offered the ability to evaluate the nitrogen (N) status of wheat during the growing season, thus allowing for more accurate estimation for N recommendation resulting in increased nitrogen use efficiency (NUE) and profit per acre.  However, the current algorithms available to Kansas producers are not designed for making N recommendations beyond jointing (Feekes 6).  This limits the use of optical sensors for intensive wheat management, and reduces the ability and opportunity for the grower to account for N mineralization.

Kansas State University has produced a new N recommendation algorithm that is specifically intended for intensive N management.  This algorithm is designed for making multiple N applications to winter wheat by evaluating the wheat crop’s current yield potential and how much yield can be obtained by making an N fertilizer application from growth stages Feekes four through Feekes nine.  The broad application range of this algorithm allows the producer to tailor optical sensor based N applications to best fit their current N management strategy regardless of the number of applications to be made or the planned time of application.  The intensive N management algorithm allows for the first N application to be more conservative so N mineralization can be better evaluated at a later growth stage so a higher NUE can be achieved without sacrificing yield potential.