While the AgroEcoLab were out in the field this summer, slashing through endless stands of Phragmites to plant lysimeters, a seven-year project funded by the NCCOS summarized their findings by stating the obvious: the invader was spreading. Specifically, the authors concluded that Phragmites australis prefers altered shorelines with elevated nutrients, a fact we had become more than familiar with. Our team’s research dealt with the previously soil-bound nutrients that sea level rise may unleash as farmlands inundate, and how this might impact our state’s fragile marshes. But as we slogged our way through farms and marshes collecting samples, we saw firsthand how pervasive Phragmites outcompeted what precious few native plants remained. The researchers behind this project advocated management efforts that prioritized wetlands and restored native communities. Beyond that, they were scant on specifics.
There are few Eastern Shore wildlife managers that haven’t heard of Phragmites. The weed chokes out natives and creates a monoculture with virtually no wildlife habitat value; it also finds convenient inroads in the many coastal agricultural plots along the Chesapeake. One study found that combined management efforts spent upwards of $4.6 million on Phragmites control between 2005-2009, with 94 percent focusing on herbicidal efforts treating 80,000 hectares. Even more disturbing, the authors concluded there was no correlation between resources invested and management success. (Martin and Blossey, 2013) Clearly, we’re in need of a new approach, and preferably one that doesn’t involve treating our most vulnerable ecosystems with toxins. In my search for a better alternative, I found something astoundingly simple: livestock. A study out of Duke University found that controlled grazing by goats and other livestock could effectively reduce Phragmites cover by about half in just a three week period, meaning this low-cost treatment has the potential to outperform just about any herbicide. (Silliman et al., 2014) Giving farmers a low-cost, chemical-free alternative to control the spread of this invasive could turn the tides of the fight, and guarantee that we’ll always have a thriving, biodiverse marsh to protect.
While it might be met with some initial skepticism, I think farmers will jump at the chance to tackle Phragmites without contracting chemical companies. Conservation managers can divert already scarce funds elsewhere, and farmers can employ one another instead. Plus, we met a few goats in particular at Anderson Farm that seemed in need of a day job.
References: Kettenring, K.M., Whigham, D.F., Hazelton, E.L.G., Gallagher, S.K., and Weiner, H.M. (2015) Biotic resistance, disturbance, and mode of colonization impact the invasion of awidespread, introduced wetland grass. Ecological Applications 25(2): 466–480.
Martin, L.J. & Blossey, B. (2013) The runaway weed: costs and failures of Phragmites australis management in the USA. Estuaries and Coasts 36: 626. doi:10.1007/s12237-013-9593-4
Silliman BR, Mozdzer T, Angelini C, Brundage JE, Esselink P, Bakker JP, Gedan KB, van de Koppel J, Baldwin AH. (2014) Livestock as a potential biological control agent for an invasive wetland plant. PeerJ 2:e567 https://doi.org/10.7717/peerj.567
A fermenter containing one of Burley Oak's fine beers
On November 16, I had the opportunity to give a tour of one of our research study sites as part of the Mid-Atlantic Crop School Tour set up by UMD Professor Bob Kratochvil. This experience was unique in that I was able to show people the effects of saltwater intrusion first hand. We hit six stops, all along Maryland’s lower eastern shore.
I spoke at the first stop. After working all summer on my site either alone or with a few other people, it felt very different to have a busload of fifty people with me this time. I took everyone on a short hike to the edge of the field where a stand of Phragmites was encroaching on the land. I showed them examples of salt damage in the soil as well. Many people had never heard of this issue for farmland and some were truly surprised to see the marsh essentially taking over a section of the field.
Then we headed over to a seed sorter. It happened to be owned by another farmer that I had collaborated with on my project this summer. He showed us the basics of how the seed sorter worked but was more excited to show us tile drainage, which he happened to be installing when we arrived. I knew about tile drainage and had always wondered how it worked. Tile drainage is an efficient way to remove excess water from a field. A tractor cuts a line at a depth about two feet into the soil and lays a perforated drainage pipe down in the cut. Another tractor comes through to smooth the soil over the cut.
At our next stop, we went to the Crisfield Airport to watch drones in action. The drones were managed by UMD faculty who showed us how they do aerial mapping. They told us that the drones were headed to Belize next to help a team of researchers study canopy cover in the rainforest. The possibilities for utilizing drones in research seem to be endless!
Next we headed to another farm field to see how phosphorus ditch filters work. They were invented by an innovative UMD alumnus who has been working to try to curb the pervasive problem of phosphorus runoff from ag ditches on the Lower Eastern Shore. The filters contain slag, a waste byproduct of the smelting process. Calcium oxalate in the slag works by reacting with the phosphorus to bind it and prevent it from polluting nearby water bodies. These filters can reduce phosphorus outflow from ditches by as much as 60%.
Our next stop was to an anaerobic digester designed by Planet Found. This group of scientists and entrepreneurs saw a unique opportunity to tackle the issue of excess poultry waste on the Eastern Shore. The digester extracts excess phosphorus from poultry litter. That phosphorus can then be cost-effectively shipped to other areas in need of the fertilizer and the manure with a lower concentration of the nutrient can be spread on to local farm fields.
The final stop on the tour was the Burley Oak Brewery. This is a small-batch brewery in Berlin, MD. The Brewmaster explained the fermenting process and other fine details of his art to us. He works with many local farmers to purchase ingredients for his beers. I tried the unfiltered Savage IPA, which was delicious!
Crop school attendees included MDA employees, Ag company reps, farmers, and environmental scientists. Discussions at dinner and on the bus showed me some unique perspectives on farming in the Mid-Atlantic. I was very pleased to see many people working on similar issues on the Shore and trying to come up with solutions to difficult problems that we face in agriculture on the Shore and the United States. - By Dani Weissman