How a biological product is helping soybeans recover from waterlogged soils

Yesterday, July 18, one of our northern Iowa clients counted 60 pods per plant on his thriving soybeans. They're loaded with blooms. Three weeks ago those beans were yellowing and wilting, with fungus attacking roots in rain-soaked soil.

July 19, 2018 — This 114-acre field of beans is an especially valuable variety grown for seed, and the grower anxiously searched for a way to fight off fungal attacks and restore chlorophyll levels. He phoned Iowa crop consultant Bob Streit, who suggested a biological foliar with an unusual name: Oll-YS from O2YS Corporation. The grower hired a spray plane to apply Oll-YS on July 2, as incessant rains had left the ground too saturated for a ground sprayer. Most of north central Iowa had endured excess rain through April and June. 

Here's a photo series showing how the beans responded — to a biological foliar, not an NPK nutrient. This is a Midwest introduction for a product already widely used for high-value vegetable and fruit crops in Southern states and California. We need to describe this cautiously: No microbe or nutrient or biostimulant is a magic bullet.

July 1: Yellow, wilting beans the day before Oll-YS was applied July 2. These imported soybeans (photo below) got off to a strong, early start. But pounding rains and nearly level terrain filled soil pore spaces and choked nutrient uptake. Roots showed brown growing points, signaling fungal attack. The grower feared early onset of SDS, the fungal complex labeled Sudden Death Syndrome. The pilot sprayed 101 acres, leaving about 13 acres for a check area. The untreated acres are higher ground and better soil, less impacted by saturation. As we understand the product, a pint per acre is a product cost of about $16.25.

Study the leaves closely: Wilting and yellowing dominated on Sunday, July 1, the day before Oll-YS was flown on. A lack of vibrant growth — a common concern we heard from upper Midwest soybean growers this past month.

 

July 5: Ground still wet, but some turgidity in the leaves. (Photo below) Recovery of chlorophyll is beginning, following application July 2. A darker green shade is emerging in a part of the field which rises gently into somewhat better drainage. 

 

July 11: New leaves emerging and a continuation of deeper green — especially on the gentle rise you can see near the top of the photo. This photo (below) was taken from the same spot as the previous two. A pause in the rains allowed soil to recover some gas exchange with the atmosphere as moisture migrates deeper into subsoil. (It's another dramatic reminder of the importance of living soils which allow rainfall to percolate deep. This grower has done an excellent job of that with gypsum and varied biological management tools for several years. We're convinced that this is an important factor enabling the biological energy of Oll-YS to flourish.)

 

July 16: Resurgence of chlorophyll in the leaves signals restored nutrient uptake from the roots. New root growth is showing up, and the brown slimy color on roots appears to recede. Farther into the field from this original vantage point in the photo below, blooms are emerging and pods are forming as the beans shift to R1 stage. 

July 18: Seen from a different vantage point on slightly more elevated ground, pod growth is vigorous. (Final photo, below) The grower is now studying options to foliar-feed some nutrients or biostimulants which could encourage further recovery and protect against a late-season invasion of SDS. A major distributor of Oll-YS, Mark Nichols, visited this field July 18 and told the grower, that Oll-YS "is doing what it's supposed to do."

So — what is this stuff, and why does it work? Oll-YS is labeled as an adjuvant and surfactant. 

The flyer for Oll-YS (see image below) describes it as containing "a proprietary mixture of food-grade chitosan and yucca extract." But it indicates that "chitinolytic organisms" are also present, meaning living bacteria which exude chitosan.

That probably refers to some variant of Bacillus amyloliquefaciens, a bacterium active in soils and also within crop roots. The bacterium works in symbiosis with crops, generating plant growth-promoting compounds and serving important purposes in fighting pathogens. A benefit of Oll-YS is that it helps encourage production of chitosan.

A substantial body of research confirms that  chitosan (a natural biopolymer and the second most abundant natural polysaccharide after cellulose) inhibits many pathogenic fungi and bacteria. Dr. Robert Kremer, now semi-retired microbiologist at USDA-ARS, University of Missouri, has done extensive study of this biological process.

It's scientifically well-known that chitosan attacks the chitin 'armor' on the stylet or penetrating point of nematodes, rendering them harmless. Biodyne USA, makers of the Environoc microbials which we market, includes chitinolytic organisms in its Environoc 401 in-furrow product. 

In our Iowa grower's case, Bob Streit tells us he plans to look into nematode counts where the Oll-YS was applied in this field. We will follow through the season and bring you relevant updates. He tells us that this product and similar ones can be classified as "elicitor" compounds, meaning a natural biostimulant which switches metabolic processes on or off. 

We've visited by phone on this technology with Mark Nichols, Sales and Marketing Vice President for O2YS corporation, and also with Dr. André Blanchard, Technology and Operations Vice President. You can see their bios at this link.

Our view is that this subject is just opening. Stay tuned for further updates in coming weeks!