Precision variable equipment

In precision agriculture, variable rate equipment is used to variably apply site-specific prescriptions. The information used to vary the rates can be based on maps created from scouting reports, yield monitor files, and remote sensing data. Different types of information are used for different problems. For example, to vary seeding rates, archived yield monitor data files may be used to build management zone seeding rate maps, whereas the collection and real-time processing of crop reflectance information may be used to vary in-season nitrogen rates. Regardless of the approach, all precision variable rate systems require the collection of accurate information, proper configuration of location and guidance systems, and calibration of equipment used to apply the treatments. Because the calculations used to determine the desired rate are of no concern to the equipment, all calculations must be checked for accuracy. The equipment will do what it is communicated by either the map-based prescription or the on-the-go sensor readings taken in the field. This chapter discusses opportunities for variable rate equipment, recent options for variably applying seeds, pesticides, and fertilizers, recent advances in variable rate equipment, the basic components of variable rate equipment, and future research needs.