The first three are more developed technologies because they may be used independently of each other, according to ERS researchers. Yield maps are created by harvesters producing location-specific crop yield data that report growing conditions during the previous year. The data then may be compiled into a map. Global positioning system (GPS) technology provides information on soil-related growing conditions on corn farms, which is then compiled into a map. Nitrogen, potassium and phosphorous levels are commonly mapped, as well as soil-type and micronutrients, the researchers said.
Self-steering combine and auto-tractor guidance systems, which also require GPS technology, have made field operations more accurate. These systems stopped tractors and other machines from missing patches or covering the same ground twice.
VRT is the only one of the four technologies that often needs to be developed in conjunction with other precision technologies. VRT enables producers to vary the rate of crop inputs, which tends to utilize mapping systems to determine the rate. Farmers may program agricultural inputs using either yield or soil maps to apply different levels of inputs at different rates within a field.
ERS researchers analyzed factors relating technology adoption and practices to estimate cost-savings from precision agriculture technology usage. In their analysis, researchers took into account the effects of acres farmed, level of higher education of the operator, and age of the operator. Per acre production cost was measured as operating costs for seed, pesticides, fertilizer, paid and unpaid labor, machinery expenses, fuel and repairs, and custom service expenses. The production cost does not take into account capital investments.