Micronutrients at Planter Time

Micronutrient Replacement at Planter Time for Better Corn and Soybean Production

Planting time is the perfect opportunity to replace micronutrients in the soil.

With crop yields continually on the rise, nutrients such as nitrogen (N), phosphorus (P) and potassium (K) are being used up in growers’ soils—but so are micronutrients. Planting time is the perfect opportunity to replenish soil nutrient supplies.

Micronutrient deficiencies can be difficult to recognize because they resemble other problems. For instance in corn, manganese deficiency produces yellowing, which can look like a sulfur deficiency or even be confused with nitrogen deficiency. Often tissue testing can determine the cause, but it is best to have a good soil test so any problems can be addressed ahead of seeing yellow leaves.

The most heavily used micronutrients by grass crops such as corn are zinc and boron. Zinc deficiency symptoms are often localized and result from specific soil conditions: high pH, free carbonates and eroded topsoil with subsoil exposed.

Manganese is important for soybeans because so many of the upper Midwest soils are short on it. Often in the summer, manganese shortages cause soybean fields to take on a yellow cast. (Note that while manganese deficiencies can cause problems, researchers have proven that recent yellow flashes appearing in some fields can be traced to a glyphosate breakdown product.

What to Use and How
Planting is usually the best time to apply micronutrients because it is easier to prevent a problem than correct one. If you see symptoms, the damage is already done and yield losses have already occured. Roots are the best avenue to feed a crop, and putting some nutrients in the root zone at planting can usually make up for shortages in the soil.

At Agro-Culture Liquid Fertilizer’s 710-acre North Central Research Station, experts conduct replicated trials with a variety of crops and nutrients. A strong performer is Micro500, which contains five main micros: zinc, manganese, iron, copper and boron. Numerous tests show that Micro500 increases corn yields from five to nearly 20 bu/A, depending on the situation. These nutrients are synergistic. Growers get better uptake and response from a micronutrient in Micro500 than if they apply an equal volume of a nutrient alone. In addition, having this combination available is helpful in pockets of a field where a grower might be unaware that a particular nutrient is lacking. Trials show that AgroLiquid micronutrients perform better than dry micros because applicators can place them in a root zone band (to the side and below the seed). Products also offer better results compared with other conventional EDTA-chelated micronutrients.

In corn, yields have shown the greatest increase with a combination of Pro-Germinator (a dual-form phosphate fertilizer with multi-form nitrogen), Sure-K (a chloride- and hydroxide-free potassium fertilizer) and Micro500. In one trial, this combination produced 213.8 bu/A (NCRS 11-715).

In soybeans, a program using the same three products generated a yield increase of 57.7 bu/A harvested. Research trials at the North Central Research Station have not only shown the benefits of using micronutrients on corn and soybeans, but other crops from asparagus to wheat also require balanced nutrition.  Research shows Micro-500 and the other MicroLink products are necessary for balanced nutrition and optimal yields.

The corn and soybean micronutrient studies are found in the 2011 Research Report, to see the most recent studies, refer to the 2012 Research Report.