Renewable Farming

Fully mature ears of corn on mostly green stalks — a residue-recapturing opportunity

Here in our little “garden spot” of Iowa, it has been many years since we’ve seen so many fields of corn maturing with white-shucked ears hanging down from mostly green stalks. Those sugar-laden stalks are ideal feedstock for a spray with residue-digesting organisms right behind the combine. 

October 3, 2019 — In the past several seasons, most cornstalks began dying down in September, reducing the amount of plant sap for nutritional use by beneficial bacteria and fungi in products like AgriEnergy’s Residuce or Biodyne’s Meltdown. Even though this fall’s general harvest progress will slide later into October than usual, you may be able to capture more carbon and nutrients from this crop than in previous years of early stalk die-down.

Huge ears in white husks, filled to the tip. Mike Williams planted this corn April 24 in northeast Iowa.

Mike Williams applied these products on this corn in northwest Iowa: 

In-furrow:  3.5 gal. per acre of 8-19-3, 1 pint  Environoc 401, 1 pint humic acid, 1 pint zinc, 1 lb. sugar with fulvic acid.

Post-plant:  1 pint (half rate) micronutrients, 1 pound of sugar with fulvic acid.

Tassel:  Fungicide plus 1 lb. sugar with fulvic acid.



Digesting and releasing nutrients in the stalk and leaf residue from a 200-bu. corn crop reclaims about 30 pounds of nitrogen, 2.5 pounds of phosphorus and 57 pounds of K. The digestion process also builds soil tilth and crumb structure, which further enhance diversity in soil microbial life. And the more green and succulent the stalk, the more nutrients are available to recycle. If stalks could be digested in mid-September when still juicy, they’d offer 45 pounds of N, 4.5 pounds of P and 96 pounds of K. 

For years, farmers encouraged by AgriEnergy Resources have hired a residue-treatment assistant such as a retired farmer to follow the corn combine with a residue spray rig. A small tractor and cheap pull-type sprayer is all you need to keep up with one or two combines. Iowa research farmer Dave Schwartz at Guthrie Center pursues the combine with a stalk shredder and residue sprayer. By spring, his stalk residue is mostly black and crumbled; easy to plant into.

Waiting to spray until after the combining rush often pushes the residue-spraying job into late October or early November. Then, overnight freezes make spraying harder to manage. And there are fewer days with over 50-degree highs, encouraging microbial proliferation.

The long-proven “granddaddy” of residue digestion biologicals is Residuce made by AgriEnergy Resources, which dates back about 30 years. In the past five years, many firms have formulated their own proprietary blends.

One of the newest comes from Biodyne USA, a firm whose founder, Dr. Fred Farley, has more than three decades of experience with microbial technology. Introduced in Iowa five seasons ago, use of Biodyne’s biologicals started with about 2,500 acres of tests — and soared beyond 350,000 acres in 2018-2019.

Renewable Farming has also tested Biodyne products, working with Biodyne rep Bob Wagner, Larry Eekhoff of Agronomy Rx, and co-op agronomist Mike Williams. In this cooperative spirit, we’ve studied how WakeUP enhances the performance of products like Biodyne’s “Environoc 401,” intended for in-furrow use. 

This fall, Biodyne has brought online a new production facility based at Wells Ag Supply of Fonda, Iowa, to more readily supply rapid growth of biological product demand in the central Midwest. 

We’ve run root-growth trials on several of the in-furrow biological products, and the responses are clear-cut. All of the spring-applied microbial spurred root growth of corn.

We have yet to see a definitive random-rep trial answering the question, “Which fall residue breakdown product is most cost-effective?” They all show definite response, and it’s difficult to quantify a precise answer.

What we recommend is a fall residue spray over stalks with Residuce or Meltdown, followed in spring with either an in-furrow or over-the-row biological with AgriEnergy’s SP-1, Biocast or Environoc 401. We can supply any of those products, and we encourage use of 3 ounces per acre of WakeUP Spring with the spring biologicals.

One of the most bemusing tests of Biodyne’s spring-applied biological, Biocast, was done in 2019 by Brody Benton, a Verdesian rep in southern Iowa. He buried three pairs of identical new men’s white cotton shorts on June 10 — one in each of three test soils.

First burial was in a field which had not been treated with biologicals. Second was in comparable soils which had been sprayed with BioCast, a Biodyne residue digestion blend intended for spring strip application over the row. The third pair of shorts was buried at the same depth in an untilled fence row nearby, where natural soil organisms typically abound.

On August 27, Brody dug up all three shorts and compared the decomposition rate. The cotton fabric of shorts in untreated soil showed little decomposition. But those buried in the fencerow soil and Biocast treated soil were both about 50% decomposed after only 78 days. 

This photo is a screen capture of a video made as Brody Benton presented some of his experiences
with Biodyne biologicals at a Sept. 11 seminar near Webster City, Iowa, sponsored by Biodyne.
On the left, little decomposition in shorts buried in untreated soils. But those buried in soils treated
with BioCast or in a biologically alive fencerow were heavily “digested.”