Don’t Leave Mycorrhizae Stranded in Your Prevented Planting Acres

Oct 07, 2019

By Stephanie Karhoff

What is mycorrhizae, and why should I care?

Mycorrhizae are beneficial fungi that colonize plant roots. They aid plants in scavenging for soil nutrients, by extending the root system via structures called hyphae. In return, plants provide sugars produced during photosynthesis to the mycorrhizae.

Mycorrhizae also produce a protein called glomalin, which glues soil aggregates together to increase soil stability. Overall, this may increase soil tilth, drainage, and the soil’s ability to hold onto essential nutrients.

How has the 2019 season affected mycorrhizae levels?

Flooding events this spring have caused many acres to go unplanted – stranding the mycorrhizae populations that require a growing crop for survival. High soil moisture levels have also led to anaerobic soil conditions that are not conducive for mycorrhizal colonization. When mycorrhizae populations are reduced, the crops that depend on them for nutrient uptake can suffer.

What is Fallow Syndrome, and how can I prevent it?

Fallow Syndrome occurs when a lack of plant growth the previous cropping year drastically reduces mycorrhizae populations. Stunting and phosphorus deficiency (i.e. purple leaves) are common symptoms associated with Fallow Syndrome. These symptoms are exacerbated in cool, wet soils that limit phosphorus availability. Reduced mycorrhizal colonization is also correlated with yield loss in corn.1

The best way to prevent Fallow Syndrome from occurring in your Prevented Planting acres is to establish a cover crop this summer or fall. When selecting a cover crop, keep in mind that Brassicas, like turnip and radish, are not hosts to mycorrhizae, and need to be mixed with either a legume like clover and soybean, or a grass like cereal rye, winter, and oats.

If you have not chosen a cover crop yet, click here to access a recent C.O.R.N. article outlining the selection process.

Source : osu.edu

Video: Spring 2026 weather outlook for Wisconsin; What an early-arriving El Niño could mean

Northeast Wisconsin is a small corner of the world, but our weather is still affected by what happens across the globe.

That includes in the equatorial Pacific, where changes between El Niño and La Niña play a role in the weather here -- and boy, have there been some abrupt changes as of late.

El Niño and La Niña are the two phases of what is collectively known as the El Niño Southern Oscillation, or ENSO for short. These are the swings back and forth from unusually warm to unusually cold sea surface temperatures in the Pacific Ocean along the equator.

Since this past September, we have been in a weak La Niña, which means water temperatures near the Eastern Pacific equator have been cooler than usual. That's where we're at right now.

Even last fall, the long-term outlook suggested a return to neutral conditions by spring and potentially El Niño conditions by summer.

But there are some signs this may be happening faster than usual, which could accelerate the onset of El Niño.

Over the last few weeks, unusually strong bursts of westerly winds farther west in the Pacific -- where sea surface temperatures are warmer than average -- have been observed. There is a chance that this could accelerate the warming of those eastern Pacific waters and potentially push us into El Niño sooner than usual.

If we do enter El Nino by spring -- which we'll define as the period of March, April and May -- there are some long-term correlations with our weather here in Northeast Wisconsin.

Looking at a map of anomalously warm weather, most of the upper Great Lakes doesn't show a strong correlation, but in general, the northern tiers of the United States do tend to lean to that direction.

The stronger correlation is with precipitation. El Niño conditions in spring have historically come with a higher risk of very dry weather over that time frame, so this will definitely be a transition we'll have to watch closely as we move out of winter.