Impact of Sensor Based Nitrogen Management On Grain Yield and Soil Components.

The Sensor Based Nitrogen Rate Calculated (SBNRC) developed at Oklahoma State University has been documented to increase profit of winter wheat production through either the reduction of inputs without loss of yield or increase in grain yields with increased inputs. The technique utilizes the GreenSeeker™ sensor, which records NDVI, to measure a high nitrogen strip place in the field at pre-plant and an adjacent farmer practice.  These values placed are then put an algorithm that provides an estimate of potential yield and nitrogen rate recommendation.  To date the studies reported were established and concluded in three years or less.  There has yet been any documentation on the long term impact of using such a technology not only on yield and economics but also soil quality factors.  This paper examines a study that was established in 2005 designed to evaluate the sensor based technologies and typical yield goal based management practices.  The study consists of six treatments replicated three times; check, n-rich plot, Yield goal all pre-plant, Yield goal 50/50 split, 0 pre-plant SBNRC, and 44 kg N ha^-1 pre-plant SBNRC.  This current year will mark the 8^th winter wheat crop harvested from the location.  Nitrogen application rates, grain yield and nitrogen use efficiency will be analyzed across years along with soil properties such as percent organic matter, surface and sub-soil nitrate levels