Yield monitors have helped farmers track crop performance for years. But to maximize profit, the data have to be taken a step further, according to Dr. Terry Griffin, an associate professor of agricultural economics at Kansas State University. Griffin spoke with Country Folks about how farmers can benefit from the creation of yield maps and profitability maps.

Tell us about yield monitors, yield maps and what insights they offer to farmers.

Yield monitors are instantaneous sensors that measure yield (flow of crop) and moisture after grain or seed are collected but before being unloaded off the harvester. Yield monitors log the sensed data on onboard devices and sometimes push to online storage in near-real time. Many harvesters have GNSS (global navigation satellite system) receivers such that the instantaneous point data can be geo-referenced, i.e., stored with latitude and longitude coordinates so that a map can be produced from the data.

During harvest, near real-time yield and moisture data are viewable on the yield monitor display screen in the cab so the operator can keep an eye on the numbers. Maps produced from geo-referenced yield and moisture data can be used after harvest for decision making for upcoming seasons.

Yield monitor data have been used to evaluate yield response from on-farm experiments where the farm operator compares new products, services, rates of inputs, tillage equipment or even timing of existing products. Sometimes yield monitor data is used in deciding if variable rates of inputs or fertilizer could be beneficial or in deciding where to place drainage structures.

Yield maps are also useful in reporting to landowners for possible negotiations; yield maps printed on coffee cups have been known to maintain landowner relations.

Why yield monitors matter

Dr. Terry Griffin is a professor of agricultural economics at Kansas State University. His research in profitability mapping has helped countless farmers maximize their profits. Photo courtesy of Terry Griffin

What about profitability maps? How are they different? What more do they offer?

When fields are treated uniformly with respect to input applications, yield maps and profit maps are essentially the same with exception of the scale of the legend, i.e., instead of yield, the map is yield multiplied by crop price which is constant across the entire field. But when input applications differ across the field, such as variable rates of seeding, fertilizer or other crop protection chemicals, visual assessment of yield maps and profit maps become much more interesting. They can show areas that are relatively more profitable and whether portions of the field may be better served in different capacity (especially with multiple years of yield data).

How can these tools be used to help a farmer identify both undervalued and overvalued aspects of an operation?

Conducting on-farm experiments has been one of the most profitable uses of yield maps along with other precision agricultural technologies, i.e., digital agriculture. When information gained from an experiment is applied to 1,000 or 5,000 acres the following year, considerable gains can be made relative to not making a “worse” decision.

Are there any other tips or best practices you’d like to mention?

When farm operators begin to make use of yield monitor data, they sometimes decide that better data can be obtained when a field is planted differently, maybe in a different east-to-west rather than north-to-south direction. This may be to avoid having the harvester moving upward or downward while the yield monitor is measuring yield; the yield monitor may not be able to make correct measurements when the harvester is operated under some circumstances, and these may be avoided with some planning.

For more information visit ageconomics.k-state.edu.

by Enrico Villamaino