Learning the ABC's of VRT

VRT potash app map

Variable Rate Technology (VRT) can be used for a variety of purposes to make automated applications of ag lime, fertilizer, seed, and chemicals as well. Federated growers most widely use VRT for ag lime and fertilizer, “but some growers are using variable rate seeding also,” said Craig Peterson, Federated agronomist at the Ogilvie location.

What makes VRT valuable? “As you cross your fields, many change elevation and soil type from one end to the other, from one side to the other; in most cases we also find changes in pH, P, and K [based on soil testing] – some at extreme amounts,” said Peterson. The variability is due to multiple factors, but with VRT it is possible to first test and then correct the erratic levels of nutrients in the geo-specific areas where variations occur.

Soil tests are the most basic way to get a return on nutrient investments, and VRT takes soil testing to a higher level with grid sampling, which “will dial in your investment,” said Peterson, by putting the right nutrient in exactly the right – most needed – place in every field.

For example, said Peterson, “Ag lime is a key step in the technology . . . we see a general lime application at 2 ½ ton per acre across a field [based on] a composite sample. When gridded you may have 4 ton [applied] in some areas and zero in other areas.” Peterson observed that in some cases VRT lime application has resulted in less lime being applied to a field overall.

P and K applications are similarly better with VRT. “In many cases we have seen the higher pH areas in the field with lower P and K than the low pH areas,” said Peterson. With VRT applications of ag lime based on grid soil sampling results, those variations can be evened out, putting the nutrients where they are most needed.

“Your dollar is invested where it’s needed and not driving high pH areas higher or under applying low pH areas,” he said.

In the end, VRT maximizes overall profitability on every acre it’s used.

Before harvest, talk to your Federated Agronomist about trying VRT. “Pick a field or two as a great start to look at variation on your farm,” Peterson said. The results will speak for themselves, proving the worth of VRT.

(If VRT isn’t in your plans, Peterson recommends getting fields lined up now for composite sampling “so when the combine leaves the field it can be sampled; then ag lime, P, and K can be fall applied in a timely matter.”)