Precision Agriculture
Glossary
V
VARIABLE RATE APPLICATION (VRA). Adjust the amount of crop input such as seed, fertilizer, lime, or pesticides to match conditions (yield potential) in a field.
VARIABLE RATE TECHNOLOGY (VRT). GPS and precise placement technology that uses an “application guidance” map to direct the application of a product to a specific, identifiable location within a field.Instrumentation such as a variable-rate controller for varying the application rates of fertilizer, pesticides, and seed as one travels across a field. VRT consists of the machines and systems for applying a desired rate of crop production materials at a specific time (and, by implication, a specific location); a system of sensors, controllers, and agricultural machinery used to perform variable-rate applications of crop production inputs; refers to a system that varies the rate of agricultural inputs such as seed, fertilizer, and crop protection chemicals in response to changing local conditions.
VECTOR FORMAT. A format for storing and displaying GIS spatial data that is stored as points, lines, or areas to create a map object. By using a nearly continuous coordinate system, vector data can be more accurately georeferenced than raster data.
VEGETATION INDEX (VI). - A ratio created by dividing the red by the near-infrared spectral bands used to identify and enhance the vegetation contribution in a digital remote sensing analysis.
