Tell me where your most productive piece of land is.
Is it over by that grove of trees? Over the hill and alongside the drainage? Down around that big hole?
Whatever your answer, let me, friend, point out one important thing to you: when you talk about your fields, you talk about zones. The field by the highway, the one south of the creek, where the snow drifts so badly in the winter, etc. Zones are physical. We can recreate them in our imaginations and with our words. They have features and stories.
Grids don’t. Odds are that however committed you might be to grid sampling and management, when I asked you to tell me where your most productive piece of land was, you yet answered with a zone instead of a grid number. Imagine that a true, in-the-flesh person—like a crop scout—posed that question to you. Imagine the poor soul’s confusion should you answer, “number 181.”
That zones better match our natural conceptions of our land is just one reason for their superiority over grids in terms of management. Zone management additionally allows for yearly soil sampling which in turn allows you to track the history of your soils and measure changes in them. Grid management, in contrast, requires so many soil samples as to make annual sampling cost prohibitive. The lack of annual samples prevents growers from establishing histories of their fields and thus measuring changes. When something goes amiss in soil managed in a grid system, it is often impossible to distinguish what went wrong and when.
Nothing is really wrong with grid management—at one point in our history, it was the best technology available—but it is 1) a lot of work and 2) simply not as representative of the reality of your fields as zone mpping.
Grid management relies on mathematical algorithms to predict the way soil changes between samples. Zone mapping, which relies on satellite imagery, uses not numerical predictions (however smart) but real measures of soil reflectivity and biomass indexing to map changes in your soil between one point and another. The numbers that dominate grid management are symbolic of the reality of your fields and the ways they change over space and time. That’s all good and fine, but why deal with the symbolic reality of your fields when you can just deal with the reality itself?
The adoption of zone mapping and its more realistic and exact representation of your fields helps you maximize your investment in your acres by supporting strategic decision making. If this is appealing, then might I mention also that zone mapping is a first good, big step toward the adoption and utilization of variable rate technology (VRT), which is the best practice available to help you achieve optimization of investments like seed, fertilizer, and water. Currently, VRT is capable of saving growers $15-$30 per acre on nitrogen by strategically placing only the necessary amount of it and in only the necessary places. Variable rate irrigation is also well on its way and is likely the next big deal in agriculture as water becomes an increasingly precious resource.
The change from grid management to zone mapping is an important step in maximizing the economic potential of your fields and an entry gate to the utilization of other advanced practices like VRT. The answer to low yielding corn isn’t always more fertilizer—often, the answer is smarter decision making and increased precision in your operation. Zone mapping supports these and additionally opens the door for you to other practices that will define the future of our industry.