Renewable Farming

Beans out, waiting on corn to dry down? Spray stalk residue digester into standing corn

Dean Craine, manager of AgriEnergy Resources in Princeton, IL, says “I wouldn’t be afraid of spraying Residuce on standing cornstalks if a grower has a window of opportunity before combining.” 

Oct. 18, 2019 — This fall could bring such an opportunity for getting stalk digestion started early. Soybeans have dropped leaves rapidly since a couple of sharp freezes, and warmer weather this week will speed soybean drydown. But even when your beans are in the bin and the grain table has been replaced with a corn head, your corn may take several more days of drying to harvestable levels. AgriEnergy has long observed that moisture exits corn kernels faster while stalks are alive, because the vascular system between stalk and ear are functional. When the stalk dies, the kernels must dry by evaporation only.

A pause between finishing bean harvest and starting corn sets up a scenario we’ve heard talked about for years, but haven’t personally seen a grower try: Spraying standing cornstalks with residue digesting microbes. Gaining two weeks or longer for establishing beneficial stalk-digestion organisms on corn could make a major difference in stalk decomposition and improved planting conditions in 2020. If you’ve had little stalk lodging or green snap, a high-clearance sprayer can drive through without mashing many leaning or downed stalks. We’d recommend 20 gallons of water per acre, plus 3 ounces per acre of WakeUP Spring for best coverage and penetration.

With daytime temps above 50 degrees and occasional showers like we’ve been having, this offers a chance to establish base populations of bacteria and fungi which munch cellulose and lignin. Corn hanging in the husk would not be affected. Nor would digestion occur so rapidly that it would weaken stalks.

A few years ago we heard second-had reports of Nebraska farmers who applied Residuce late in the season on standing corn through their pivot irrigation system. One full rotation and the job is done. We haven’t been able to track down the source, it but sounds like a cost-effective idea. 

Yettter Devastator rolls under combine head on Steve Schmidt farm, Iowa

You also have access to several technologies for aggressive stalk munching with the combine. Aggressive rolls like the Calmer chopping rolls or the 360 Chainroll crack the tough outer lignin and open up the soft interior pith to moisture and microbes. We’ve done some research with the Yetter Devastator and found it helpful for crimping and flattening stalks. It’s also a useful tool to reduce tire damage on combines and tractor/grain wagon units.

Our standard recommendation is to line up a retired farmer to chase the combine with your lighter-weight utility tractor and cheap pull-type sprayer. If the sprayer gets caught in a freeze overnight, you haven’t damaged your $250,000 new GPS high-clearance rig.  We’ve bought nice towed sprayers with 60-foot booms for around $2,000.

Iowa research farmer and Veridian manager Dave Schwartz uses a wide flail-type stalk chopper teamed with a spray boom for applying Meltdown, a residue digester from Biodyne USA. There are many, many other bugs-in-a-jug or dry blends you can use for the job. We wish someone would do a field-scale trial comparing the newer digesters!

Leading Iowa crop consultant Bob Streit recommends a stalk digestion treatment, noting that  “It should be step #1 in your 2020 disease control program,” especially if you’re planning corn after corn in 2020.

When we mentioned spraying a crop digester early into standing corn to one of our innovative clients in north central Iowa, he told us, “I would have tried that if I had thought of it!”  He has a new high-clearance sprayer with a 120-foot boom, so it wouldn’t take long to get over the 500 acres of corn he has yet to take out.

His high-clearance spray rig already earned big dividends this season by Y-dropping 105 pounds of 32% (about 34 units of N) with a stabilization product. Corn where he Y-dropped N outyielded untreated corn by 20 bu. per acre. His best fields are ranging between 275 to 285 bu. per acre.

Piggybacking a fall-applied herbicide with a fall residue digestion spray is another money-saving idea. More growers are using fall residual applications to control overwintering weeds, reducing spring weed pressure. Tank-mixing weedkillers with residue digesters saves a trip. Gromark has a background report on fall weed control at this link.