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Variable-rate applications (VRA) of nitrogen (N) fertilizers are a new option to assist producers with real-time fertilizer rate decisions. Two commercially available systems that allow variable-rate nitrogen applications are GreenSeeker (Trimble Navigation Limited; www.ntechindustries.com/greenseeker-home.html) and the OptRx Crop Sensor (Ag Leader Technology; www.agleader.com/products/directcommand/optrx/). A discussion of the science behind these systems, potential economic benefits, and other methodologies to make VRA is discussed in Virginia Cooperative Extension publication 442-505, “Precision Farming Tools: Variable-Rate Application” (Grisso et al. 2011).
Virginia Cooperative Extension materials are available for public use, reprint, or citation without further permission, provided the use includes credit to the author and to Virginia Cooperative Extension, Virginia Tech, and Virginia State University.
Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Edwin J. Jones, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; M. Ray McKinnie, Administrator, 1890 Extension Program, Virginia State University, Petersburg.
August 8, 2014