Mid-summer is an excellent time to evaluate microbial activity in your fields. Do you see white michorrhizal fungi? Are the residues degrading? How is the soil structure, does it have a nice crumb structure? Smell the soil, is it a good earthy smell?
August 3, 2017 — Here’s an update adapted from a field report by AgriEnergy Resources.
On a field visit in central Minnesota, an AgriEnergy dealer saw some major things happening in his client’s soil. The grower had broadcast a mix of AgriEnergy’s SP-1™, Residuce WS® and nutrients on corn stalks early last spring, then planted soybeans.
He left a pass untreated as a check strip. The dealer and grower digging roots saw that the untreated strip compared with the rest of the field demonstrated the power of biology to make distinct and beneficial changes in soil in a single season.
The nearby photo shows a spade full of treated soil. You can see signs of microbial activity: Tendrils of white fungi (the “stringy” stuff) and a crumb structure. There was also lots of soil clinging to the soybean roots, and a good earthy aroma. It looked, felt and smelled alive!
Then, upon digging in the check strip (not shown), the soil had an entirely different feel to it: no visible fungi, pieces of corn residue fully intact from last season, a more blocky structure, and a totally different smell. Definitely not as alive!
The presence of a rich, wide array of beneficial microbes helps make soil nutrients available to plants at a steady rate. The microbes go to work breaking down organic materials into forms readily absorbed by the plant.
Plants grown in a soil that’s alive biologically also have an active rhizosphere (the area immediately surrounding the roots) resulting in a larger root mass, with more soil attached to the roots. Microbial secretions act as “glue”, binding soil particles and organic matter together with a substance called glomalin. This results in improved tilth and aggregation — that “coffee grounds” structure.
We recommend broadcasting a spray of Residuce along with nutrients on crop residue as quickly after harvest as possible, to allow microbes to bloom before soil temperatures drop sharply. We have Residuce available at our WakeUP plant here in Cedar Falls. Some growers who’ve used Residuce for years arrange for extra help to run their field sprayer almost “behind the combine” to gain the maximum fall incubation time for the residue-digesting organisms to work. Today’s tougher-stalked corn hybrids with high lignin content especially need that time to digest before next year’s crop starts the seasonal surge in nutrient demand.
Our ideal for fall residue treatment on corn is this: A sprayer-equipped tractor and stalk shredder chases the combine, running almost on the ground to shatter stalks and coat them with a spray of Residuce plus a nutrient mix to jump-start the beneficial fungi and other microbes in Residuce. A pound or two of dextrose or molasses in the solution accelerates that microbe bloom. It’s worth finding a helper to get this done while you’re managing harvest. Here’s a link to an earlier, comprehensive report on how Jim Mitchell of Ohio gets this job done as one of his fall priorities.
Several companies offering biological products now make a “stalk digester” blend. Residuce has been refined for about 30 years and is a mainstay with clients of AgriEnergy Resources of Princeton, Ill.