Doubling the Size of the Cover Crop “Pie”

That’s the impetus behind GO Seed’s recent hiring of Dr. Shannon Cappellazzi: to scientifically demonstrate the value of – and increase the market for — cover crops.   By working more closely with farmers and universities to facilitate research on what’s going on beneath the ground, the company hopes to determine which varietals of cover crop, turf, and forage seeds will best help farmers reduce input costs, increase profits, and mitigate the impact of climate change.

“Leveraging Shannon’s expertise in soil and plant relationships and her wide network within the agricultural research community, we’re going to be able to understand so much more about the impact of products and current management practices on the environment,” says Jerry Hall, co-founder and head of breeding for Salem-based GO Seed. “Much of the research will be in the public domain, so this will benefit our entire industry.”

The idea of hiring a highly respected soil health scientist to help shepherd research grants came to Hall when he was asked by a land grant university to design a study on perennial cover crops. He recognized that there was a desire and need for more industry guidance and input on research and Dr. Cappellazzi, who is a member of the Soil Science Society of America and serves as a board member of the Oregon Society of Soil Scientists and the Oregon Forage and Grassland Council, was an obvious choice to help lead these efforts.

The study of soil health requires an integrated approach, so facilitating interdisciplinary research will be an important part of Cappellazzi’s work. “While there may be a great agronomist at Washington State, that person is only dealing with agronomy; and the amazing microbiologist at Oregon State is only dealing with microbiology; and the top-notch crop scientist at Utah State is only dealing with crops.  Our goal is to help build interdisciplinary teams to design research projects that reflect what farmers are dealing with, which often crosses multiple disciplines,” says Hall.

“Nothing happens in a vacuum – the data doesn’t make sense if we don’t connect the dots,” said Cappellazzi, who brings her background in animal health, economics, and entomology studies to soil research. “I’d like to see experts from a wide range of disciplines studying the same set of treatments to see how their specific science is influenced by place-based soil characteristics, crop varieties, and management practices. We’d explore the whole interactive system from multiple angles.”

GO Seed is looking at three parallel paths for their initial research: carbon additions, root architecture, and mycorrhizal associations.

To claim anything meaningful about carbon sequestration, Cappellazzi believes, it is necessary to know how much carbon is being added by a specific plant and how those carbon inputs interact with the soil, biology, and management to understand how much remains in the soil. Long-term measurements, over time, are needed to determine the impact of place and management practices.  “When producers want to join a carbon market, they want to know if the products will get them to their goal. If we can quantify the carbon addition, that’s going to have an impact.”

Studies have shown that there is more carbon in the top meter of soil than in all of the plant biomass and the atmosphere combined. Still, between 30-50% of the carbon that was previously in agricultural top soil has been lost.

“Where did it go? The carbon has to move somewhere,” says Cappellazzi.  “When we reallocate that carbon from the atmosphere through photosynthesis back down into the soil through roots, we move in the right direction.”

Looking at the amount of carbon in the root biomass and exudates is part of the calculation for carbon additions and informs GO Seed’s second research focus on the root architecture.

“We know if carbon is put down deeper in the soil, it’s more likely to stay in the soil. There’s generally less microbial activity deeper so carbon is not being turned over as quickly,” says Cappellazzi. “We’ll be looking at the total volume and the biomass of roots, but also where those roots are exuding materials and where the root die-off is. Where that happens in the soil profile is going to influence how long that carbon is going to stick around.”

The third research focus will be on mycorrhizal associations, which are known to help cash crops with nutrient acquisition and water use efficiency, and to enable input reduction. If plants have a higher rate of these mycorrhizal associations, it is better for plant health.

“We want these mycorrhizal associations in the main cash crops, but there are some mycorrhizae that will associate with both the cash crop and the cover crop,” says Cappellazzi. “If we can work on building the hyphal networks and these mycorrhizal associations during the cover crop time, we think that will enhance the cash crops’ propensity to form mycorrhizal associations, as well.”

In some cases, farmers are ahead of universities in their research.  The orchard and vineyard industries, for example, had been focused on above ground biomass, but are now looking below.  Keith Berns, co-founder of Nebraska-based Green Cover Seed and a popular speaker on the soil economy or “carbonomics,” said, “Interest in cover crops and other regenerative agriculture tools is at an all-time high.  The creative applications of cover crop species by innovative farmers are really pushing the limits of the current seed offerings on the market.  We need new and improved cultivars of cover crops to help these producers meet their goals.”

“Farmers are taking a lot of risks on large-scale experiments over acres of land while much of the research at universities is conducted on square meters,” says Hall. “This doesn’t always reflect the variety of soils and other factors found on real fields or pastures.”  Cappellazzi is hoping to facilitate more on-farm studies and even to build a network of farmers across the country to do trials with different variables to determine the impact on yield, crop quality, ecosystem health, and profitability.

“For hundreds of years we thought we knew how to farm, but looking back now, I realize that we only knew how to destroy our soil instead of how to foster it and embrace it’s true potential,” said Jimmy Emmons, a well-known no-till farmer and conservation advocate from Oklahoma. “Dr. Cappellazzi has knowledge about the biological world and its ability to save our soil and to regenerate it back to where we started. Her work will help us understand how cover crops not only help protect the surface from erosion and extreme temperatures, but most importantly, how they feed the biological community so it can feed the soil and in turn, feed us.”

It is well known that in order to sequester the most carbon, tillage must be avoided, but Cappellazzi would like to know how what happens when cover crops and no-till are combined. How does this increase the efficacy of one or the other? How does the combination build up the system? And how can the cover crop industry encourage farmers to adopt these?

Universities from Oregon to Georgia have been studying nutrient cycling, but there remain questions about no-till situations where the nutrients are not incorporated into the soil. How does microbial presence factor into nutrient availability?  And even with nitrogen-fixing cover crops, do farmers need to use more nitrogen?   How much nitrogen becomes available during the growing season and what is the timing of its availability?

“Our goal as an industry is to help producers make sound economic decisions. We know there’s a cost in purchasing seed; we plan to add to the growing body of evidence that shows the upfront costs will be made up for by reduced fertilizer, water, labor, fuel, and chemical input costs,” says Cappellazzi. “But different species perform different functions in the system and varieties have different potential. We want to use these cover crops as tools to address producers’ goals; it goes back to GO Seed’s tagline, ‘Novel solutions for growing concerns’.”