By Brian Morgan

“Although cellulose is the most readily available food (and energy source in the world), animals delegate the difficult task of decomposing it to the microbes living in their gut,” say David Montgomery and Anne Bikle in The Hidden Half of Nature, one of my favorite science-driven agricultural books. While microbes are breaking down cellulose (the fibrous component of plants) in a cow’s stomach, they are also working to make nutrients available to plants in soil.

One of the best ways we can encourage this massive lift of microbial life is to regularly add compost to our fields and veggie beds.

To think of compost as a sort of probiotic in the soil may be kind of odd, but it portrays the activity and significance of that material we often think of as inert. One inch of dark-chocolate-colored compost on top of our veggie beds helps us in so many ways, both now and in the future.

A layer of compost on garden beds gives us the option to plant directly into it

In the near term, adding plentiful compost to our veggie beds helps to create a fluffy surface for planting - whether we are direct seeding or transplanting. If we have the ability to go heavy on compost, it also contributes to weed suppression, burying the weed seeds that exist in the soil beneath. So it gives us the option to plant directly into it, it gives us increased confidence that the plants are able to uptake the nutrients they need to thrive, and it contributes to the long term composition of the soil, the ability for it to take in water, and the likelihood its structure will become more robust, wherever it is added.

“One of the best ways we can encourage this massive lift of microbial life is to regularly add compost to our fields and veggie beds.”

The Livestock team, managed by Ed Pitcavage, does the collection, composition, and maintenance of our compost here on this farm. The Garden team (myself included) just gets to reap the rewards!

I spoke with Bennett Weinberg, Land and Livestock Equipment Lead, to get more details on what goes into the process. “In June and July, the peak of our compost making season, we might have four windrows of compost to build and to turn over for aeration,” says Bennett.

Cows in our pack barn in the winter months

Each windrow is about 150 cubic yards, or the volume of a very large residential swimming pool, and it takes several hours just to turn all the material, which is done on a weekly basis. Turning the windrows introduces oxygen and incorporates more materials to encourage the large mass to stay steaming in the 140F to 160F range, and to continue to decompose.

“The scientific community is still learning so much about what’s happening beneath the soil surface.”

Hay will be combined with woodchips and sawdust to create bedded pack in the pack barn

Where does all that material come from? The cow/calf group enjoys a plush flooring of hay and wood chips (called bedded pack) throughout the winter months, and that hay all comes from the fields at Philo Ridge Farm.

There is also bedded pack from the sheep group, steer group, chickens, and pigs, which all have varying combinations of hay, woodchips, sawdust, and animal waste. The diversity of inputs from these different animal groups also helps balance the end product of compost.

Bennett continues, “We put roughly 130 hay bales into the winter pack barn for bedding alone, and then feed out twice as many throughout those colder months. What’s really cool is that as the animals live in that space, they trample the hay, their manure and urine get incorporated into the bedded pack, and when we remove that material for compost, it’s already actively breaking down, accelerating the composting process as other organic matter is incorporated.”

“The on-farm poultry slaughter facility is another great source of compost inputs. We have 1,000 gallons of nitrogen-rich wastewater from the poultry plant-in-a-box that helps catalyze the breakdown of compost while also adding nitrogen.” During the season, this is happening on a weekly basis.

Turning the windrows introduces oxygen and incorporates more materials to encourage the large mass to stay steaming in the 140F to 160F range, and to continue to decompose

After 4 months or so, the compost is decomposed and transformed enough to be spread on the pastures in the fall, and another 2 months after that the granules are fine enough for application on our veggie beds. If we need to sift the compost further, we use our on-farm sifter, which results in a really fine end product that gives us more flexibility to direct seed or plant into. The downside is that it takes us more time to also sift it, so the decision of whether or not to sift comes down to where that compost will go.

Regardless, we have flexibility and plenty of potential applications, and whatever we don’t use in the veggie beds can always be happily applied to the pasture. As a team we’re often observing what’s working and what we might like to change, but the basic on-farm inputs we have available for compost, and the team that’s doing it is churning out an amazing product that we are so lucky to benefit from.

The scientific community is still learning so much about what’s happening beneath the soil surface, and the connection between microbes in the soil and microbes in our gut. But it’s pretty clear that adding compost to our soil is nurturing a vibrant, healthy environment on multiple fronts.

As Anne Bikle and David Montgomery say in The Hidden Half of Nature, “A couple of decades ago, it would have sounded crazy to argue that plants and microbes in the soil run a biological barter system that functions as a plant’s defense system and allows us to harvest nutrient-laden plant food essential to our health… In medicine, as in agriculture, what we feed our soils—inner and outer—offers a prescription for health forged on the anvil of geologic time.”

The Art and Science of Composting