Self steering combine
Self-steering combines, which require G.P.S. technology, have made field operations more accurate.

WASHINGTON — Information-based production (precision agriculture) technologies have seen rapid growth in the United States, according to a May 2 article on Amber Waves, an on-line publication of the Economic Research Service (E.R.S.) of the U.S. Department of Agriculture. The advancing technologies allow farmers to more closely monitor farm-production management decisions and possible cost savings. The four most commonly used precision agriculture technologies are: yield mapping, soil mapping, auto-guidance machinery steering, and variable rate technologies (V.R.T.).

The first three are more developed technologies because they may be used independently of each other, according to E.R.S. 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 (G.P.S.) 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 G.P.S. technology, have made field operations more accurate. These systems stopped tractors and other machines from missing patches or covering the same ground twice.

Auto-tractor guidance system
Auto-tractor guidance systems stop machines from missing patches or covering the same ground twice.

V.R.T. is the only one of the four technologies that often needs to be developed in conjunction with other precision technologies. V.R.T. 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.

E.R.S. 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.

Yield mapping, used independently or with V.R.T., was determined to have the highest savings among corn farmers using one of the four precision agriculture technologies, the researchers said. Farmers reported having saved about $25 per acre. The yield mapping provides information on the growing conditions throughout the year, which reflects the yields across the farmer’s fields. The yield mapping provides useful information regarding the effectiveness of recent practices, with savings from the technology estimated at almost double the $13 per acre savings reported from soil mapping with G.P.S. Because soil mapping uses individual data points on a soil map, each point requires individual geo-located soil tests.

The researchers found a similar cost-saving effect when V.R.T. was used with soil mapping. V.R.T. with yield mapping has slightly higher per acre savings than V.R.T. with soil mapping (about $22 compared to $21), they said. Guidance systems utilizing G.P.S., which require tractors and other mechanical hardware, post per acre savings higher than G.P.S. soil mapping ($15 per acre). The systems save fuel and wear on the machines, as well as hard to measure factors unaccounted for in the savings like operator fatigue and stress-related factors.