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Maximizing Soil Health with Compost

ELA invited a few members to talk about the compost they use, how they are utilizing that resource, and their compost sources. They also offer tips for managing soil.

Contributors

Willow Cheeley, Owner, Circle E Landscape Design, Andover, MA

Shawn Mayers, Designer/owner, groundSwell Designs, LLC, Jamestown, RI

Peter Shotzberger, Compost & Chemical Specialist, Mt. Cuba Center, Hockessin, DE

Tom Sullivan, Principal, Pollinators Welcome, Turners Falls, MA

Edwina von Gal, Principal, Edwina von Gal + Co and founder of Perfect Earth Project, East Hampton, NY

What types of compost are you using as soil amendments? With what success?

Photo courtesy Mt. Cuba Center

Peter: We use compost that we make here at Mt. Cuba Center. We mix our greens from the garden, wood chips from our chipper, and leaves. We monitor our temperatures while composting to ensure we get above 131 degrees and stay below 165 degrees, flipping the piles to keep them aerobic. We send samples out to Soil Foodweb and Penn State to see what quality compost we have. Our compost comes back with pretty good results.

Edwina: I make compost from kitchen waste, mulch mowed leaves, clean cardboard and paper, chicken manure from a local farm, and seed-free garden cuttings. I add it back to the veggie and flower/shrub beds and for planting. It isn’t fantastic because I don’t take care with correct proportions and it doesn’t get hot so there are always some weed seeds.

Shawn: We typically add about two inches of certified organic, screened compost to planting beds. The compost is made locally and sourced from local materials – and usually has high shell content.

Willow: For personal use, I have tried Coast of Maine lobster and blueberry composts and am not a fan of the blueberry compost because of the peat in it. Overall these seem to dry out.

Mad Mics mulch (Shirley, MA) is a good amendment – it is composted horse manure and bedding. Not technically compost, but works very well as a topcoat amendment.

This year I will be trying Brick Ends Farm compost and Organic Mechanics products based on recommendations and because they test their compost. Otherwise I have been very hesitant to use most compost – worried about toxins, anaerobic processing, and pathogens. I’m especially hesitant if I don’t know that they sieve out worm eggs.

Tom: In the last few years I have used a few commercial composts from relatively small operations in Franklin Co, MA. I usually use compost as a top dressing and am learning to apply less and less since most of my plants are native. I am trying to match the plant with the site rather than aiming to turn the soil into something else. Many native perennials become too big and floppy with thick applications of compost. I have had better success using commercial compost on vegetable gardens.

How are you applying compost and in what quantities?

Tom: When I do apply compost, I use it as a top dressing and only a few inches, rather than 4” to 6”.

Edwina: I apply a couple of inches on my fallow vegetable beds in fall. I wait until spring to put it on ornamentals as the voles love it and have been moving in and eating roots and stems.

Shawn: Since we are mostly dealing with new construction, the compost is mixed with native soils and tilled in to make a nice, loamy planting bed.

Peter: We have been applying most of our compost to our turf areas and some to the beds in the gardens. On the turf we are applying 0.5 cu. yd./1000 sq. ft. using a Eco lawn spreader and a compost spreader that looks a lot like a manure spreader but made for compost and other top dressings. Soil testing is important. You want between 3% to 6% organic matter in your turf soil and a 1:1 fungal to bacterial ratio. For your woody plants, you would want a higher fungal ratio depending on the type of garden.

We also have been using brewers to extract from our compost and brewing Compost Tea for the gardens and turf. Compost Teas are when you add things to your brewer while extracting to multiply what’s in your compost. If you don’t add foods to your brewer you are extracting from your compost. We find out through testing what we have in our compost and then can add different foods to increase what we need in our tea or extraction. We apply 100 gallons of tea per acre.

Photo courtesy Mt. Cuba Center

Have you found a reliable source?

Shawn: Yes, Earth Care Farm in Charlestown, RI is the best.

Edwina: For my clients we get leaf mulch from town landfill, but it is not as complete as it could be. Some of the contractors I work with have a source up island they like, but it is always a challenge to get great stuff.

Tom: Yes. I like Martin’s Farm compost in Greenfield, MA.

Do you have a soil management tip you’d like to share?

Edwina: I am trying to learn more about the soil biome so I can work on making it healthy. I will send samples this spring to the Soil Food Web Lab that Paul Wagner runs. http://www.soilfoodwebnewyork.com/

Peter: A good thing to keep in mind is you need to know what you have before you add things to your situation. Therefore soil tests are a critical part of doing anything to your soils so you know what is there and what needs to be changed for the appropriate situations.

Shawn: With new construction, soil erosion is a big problem when topsoil is stockpiled on site. We often ask the builder to plant a cover crop (winter rye, for example) to help keep soils in place. When it’s time to spread the pile, the rye adds organic matter, and since it’s an annual seed, won’t cause weeds.

Tom: This question seems easier to answer when there’s a lot of tillage to raise vegetables. With native perennials I believe soil becomes easier to manage when most of the heavy work is done up front to undo compaction and/or over acidification. When faced with a clay soil, I would use more compost than on sandy sites.

Willow: I have a few tips. I have not found bark mulch to be good for soil. Focus more on getting life into the soil rather than on pH or other standard soil tests. Be patient. Don’t leave bare soil exposed (except a little for the digger bees and wasps who are very beneficial). Don’t try to change the soil radically to accommodate plants that don’t belong there in the first place. Think about existing allelopathic plants that may be contributing to soil issues.

Tom: I agree with Willow about leaving bare ground so that native ground nesting bees have easy access to the soil. To support native bees I suggest:

1) using compost and/or mulch only at the base of the plant rather than broad scale on the soil surface

2) adding mulch only in shady areas where native ground nesters are less likely to nest

3) leaving well-drained soil in sunny locations open to favor ground nesting bees where they’ll find easier digging and better larval development due to the warmth and fewer fungi to contend with

If you see bees nesting in ground you intend to plant in, be sure to give them a wide berth and conserve this valuable resource by increasing the plants they currently are feeding on and research what else you can plant that will help them proliferate.

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