N-STAR: Connecting The Dots For More Sustainable N Fertilizer Management.

The University of Arkansas directs one of the few remaining “free” soil testing programs in the United States and has long been a leader in the development, correlation and calibration of soil testing methods for Mid-South row-crops such as rice, soybean, corn and wheat. Researchers at the University of Arkansas have led the way in the development of the first soil-based N test for rice; N-STaR. Soil-based N tests have been the focus of soil fertility research programs for the past 50 years and the recent success of N-STaR highlights the importance of continually developing new soil test methodologies and ensuring current methods provide the proper rate recommendations. The research involving N-STaR in rice has involved both small-plot and field-scale validation in production fields and has led to the incorporation of the soil test on a wide scale.Continued work in wheat shows the ability of this soil analysis procedure to predict N rates for upland crops. Future work will focus on the devlopment of this technology for corn. In a world of rising commodity and fertilizer prices coupled with the increase in potential environmental impact the identification and application of proper nutrient rates has never been more important.