A new study on soil fertility in 12 Corn Belt states is showing a large number of tested fields are deficient in phosphorus and potassium, or P & K. Deficiencies in those two primary nutrients for a corn crop can rob from yield in both corn and soybean fields, squeezing that field’s profit potential.
Kirk Reese, Agronomy Research Manager for DuPont Pioneer which conducts the survey, said Indiana soils score well in fertility.
“What we found was that Indiana by and large from a phosphorus fertility point of view is in pretty good shape. I’d say greater than two-thirds of the samples that we collected, of which there is over 1,100, so it’s a fairly good sample size, were in that optimum to high range. That’s the good news, but the other news is that about a quarter of those samples that we took were below optimum for phosphorus fertilizer. So there is about a quarter of the fields that we sampled that we saw some kind of deficiency in phosphorus.”
Reese said the majority of sampled soils in Indiana also scored well in potassium levels.
“Three-fourths of the fields that we found were in the optimum to high range for potassium, but again about 20-25% of the fields we sampled were low in potassium fertilizer as well.”
“The next step is to go get grain harvest off those locations and then try to match up what yield results look like vs. fertility levels. So that’s the next step and will be made available after harvest season.”
The majority of the soil sampling in Indiana was done north of Bloomington and all the way up to the Michigan border. Samples in the south are scarce because of the amount of rain in the spring. Throughout the Corn Belt there were more than 22,000 soil samples, and the overall negative nutrient balances could be impacted by higher nutrient requirements from the more productive hybrids and varieties in use today.
DuPont Pioneer offers the Encirca Fertility service to help farmers with a precise and efficient fertility management program. Talk to your local Pioneer sales professional for more details on the fertility trials.
The study was conducted as part of the Pioneer® GrowingPoint® agronomy program, which provides valuable management insights for growers on production practices to help growers improve yields. Pioneer has developed individualized P and K reports for states and regions, as well as aggregate results for the Corn Belt.