How you can unlock the small secrets to big yield gains
All plants need 17 nutrients to survive and thrive. Catherine White, a plant nutrition specialist with WinField, says fertility thrives on synergy, and while nitrogen, phosphorus and potassium get top billing, several micronutrients play important supporting roles.
"There are several essential relationships between macronutrients and micronutrients," she says. "Very few processes in the plant only involve one nutrient. Most systems are driven by nutrient interactions."
In particular, wheat needs four micronutrients to capitalize on big yield boosts, explains Ron Olson, senior agronomist for North America with The Mosaic Company.
"The importance of micronutrients steps up a bit when you want to grow high-yielding wheat," he says.
Zinc. Nutrient interaction is very much a "team sport," Olson says. Zinc is a prime example—it plays a vital role in assisting phosphorus uptake.
"Zinc is the spark plug," he says. Zinc deficiencies are most common in sandy soils and soils with low organic matter. They also tend to occur more often during cold, wet spring weather. Around 75% of soils east of the Mississippi would likely benefit from more zinc in the profile, Olson says.
"That’s why a really good soil-testing program is so important," he adds.
Boron. In all crops, boron is directly related to the reproductive functions of the plant, Olson says."If wheat is short on boron, you’ll have flowering and pollination problems," he says, adding that boron is critical for stem strength, as well.
Boron deficiencies tend to be more pronounced during drought conditions when root activity is more restricted, Olson says.
Chlorine. When nutrients such as calcium, magnesium or potassium need a lift, chlorine gives them a ride.
Chloride is also needed for stomata regulation, which minimizes water loss during drought stress.
Copper. This micronutrient drives home why soil testing is so important, Olson says. If the soil pH is too high, wheat plants will struggle to take up enough copper, he says. But if the pH is too low, copper could be present at a toxic level.
Farmers with heavy clay soils need not worry about copper deficiencies, Olson says, but fields with high organic soils are more vulnerable.
Mosaic has developed an educational tool for these and other key nutrients at www.cropnutrition.com.
Seed companies are reaching out to learn more about micronutrients as well, White says. All of WinField’s Croplan corn seed comes coated with zinc, for example, and their agronomists investigate data generated from Answer Plot trials to further develop a sound nutrition plan.
"Looking at nutritional needs season-long has become an educational initiative for us," she says.
Strip Trial Tips
A research team at Kansas State University has seen yield gains vary by soil type from their wheat micronutrient trials. As a result, they encourage farmers to conduct their own strip trials to try new practices or products to identify what works best and where it works best. Remember:
- Keep on-farm trials as simple as possible.
- Control all variables in replicated trials so results will be statistically repeatable.
- Use three replications of the treated and check strips in each field or farm.
You can e-mail Ben Potter at email@example.com.
- February 2014