Farm Scale Composting

Herman Holley and Louise Divine own and operate Turkey Hill Farm, a vegetable and fruit farm in Tallahassee, Florida. This farming couple has worked tirelessly over the years to grow the local food movement in the region. Turkey Hill is a founding farm of the Red Hills Small Farm Alliance which provides the Red Hills Online Market for its members.

Of the many factors that allow the farm to thrive, the most critical is a dedication to soil fertility. Over the years Herman has developed a composting process as the core of their soil fertility management.  In the areas longest under cultivation soil tests have documented that the percentage of soil organic matter has increased over the years from 1% to 7%.

Before buying the farm in 1999, Herman and Louise had always gardened and composted on a small scale. “There was only one acre of land that was not planted with pines, but its soil was exhausted. We knew that to bring it back we needed compost,” said Herman, a dedicated composting missionary.  “We cover crop too, but we grow year-round here, so we need a more intensive way to build and maintain the soil,” he said.

The Recipe

At the beginning of their farm years, one of their neighbors made horse-stable muck available to them. They sheet composted with this material until they got a tractor with a bucket which allowed them to begin hot composting it.  They expanded their composting scale by getting a dump trailer to haul stable muck from other sources.   Stable muck, a mixture of pine shavings, hay and horse waste from stalls, if it is reasonably fresh, readily heats up beyond the necessary temperatures.  This was the basis for their composting for several years.

One day, at their Saturday farmer’s market, they chatted with a seafood supplier. “They had quite a bit of fish waste, and this material would go to a dumpster, a special dumpster, it was a headache for them… We said, we’ll come and pick this up from you and they thank us for making it easy on them,” Herman said. So, they have replaced the stable muck with “fish and chips”.  Two to three times a week Herman gets fish waste from the local fish market. Herman believes that the fish provides a broader spectrum of trace minerals, since it is coming from the ocean.

Turkey Hill Farm has become well known among the workers who clear the power lines of encroaching trees.  Herman said, “We make it easy for them to drop their chipper trailers, maneuver their trucks, dump their chips, reattach their chipper trailers and get back to work.” They will travel considerable distance to dump here because it is easy and free.”

Building and Managing the Piles

Turkey Hill’s dump trailer handles 6 cubic yards of wood chips per load.  “I dump these 6 yards of wood chips in the composting area, then I create a depression in the middle of the pile and I dump six 32-gallon containers of fish waste. So, the rate is 1 cubic yard of wood chips to 32 gallons of fish waste. After dumping the fish, I thickly cover it with 1-2 feet of chips.”

In the space of two weeks, Herman makes six piles like this. After making the last one, he lets the six piles rest for one week. After this he does a thorough mixing of the 6 piles, making a bigger 36 cubic yard pile. In his experience, smaller piles require more management.  “30 to 40 cubic yards is a good size to hold the heat and not get too soaked when it rains or dry out in a dry time,” he said.

Herman uses his tractor front loader to pile up and turn the ingredients. He knows that the process is working by checking the temperature with a 2 foot-long thermometer. His farm was certified organic for two years in the past, and he had to closely monitor record the temperatures in his piles of horse-stable muck.  Due to this experience, he can tell when it’s time for turning the pile. The minimum volume to create good conditions for composting is 1 cubic yard. “It’s easy to reach temperatures in 130’s °F.  The temperature increases and reaches a plateau; when the temperature drops, this is the time for turning. After you turn, it will heat back up, plateau for longer this time and eventually start to drop.  Turn it. When it will heat back up to only 115 to 120 °F it is ready to use, which typically happens in two to three months,” Herman said.

Advice for Dealing with Challenges

Smells: After the first turning even fish and chips compost shouldn’t smell bad.  Aerobic decomposition doesn’t smell bad.  “You can tell by the smell when the pile starts to go anaerobic, it has a sour smell. You need to turn it to get air back in it.”

Air: Herman warns against compaction. The compost pile needs to be porous so that enough air can enter the pile. When turning, Herman turns the pile uphill, that way he minimizes compacting and prevents early stage run off into a more advanced pile. In his experience, air can be the most common limiting factor. “Usually, the temperature of the piles goes down when the pile can no longer breathe; it’s time to turn it again,” Herman said.

Vultures and Vermin: They have had problems with these creatures before. Herman has tried chicken wire in the past, but has moved away from using it. From a fellow farmer he learned that by putting some material from the next older pile, one layer on top of the new pile helps to inoculate the new pile and apparently discourages or confuses any creature from digging in the pile.

Managing moisture: When Herman knows there is a big rain coming, he manages the pile according to the level of moisture. If the pile is dry, Herman sets up the pile in a concave form, so that it catches more moisture. On the other hand, when the pile does not need more moisture, he places the pile in a conical shape to prevent too much rain entering the pile.  It is important to have a water source available as you may need to irrigate when there is drought.

Finished Compost: Herman recommends making sure that the composting process has finished. “When the compost is unfinished, applying this material to your soil could tie up nitrogen; as the microbes use the available nitrogen in your soil to finish the composting process,” he said.

Using it, enjoying the benefits

When the material is finished, he applies two inches of this sterilized material to the crop beds.  It is a method Herman calls the “sterilized mulch method.” He does not incorporate the material. The material reaches temperatures of 130 to 140 °F and this kill weed seeds and other pathogens. “After application we don’t have much trouble with weeds. No cultivation is needed either as there are no weeds and the soil does not get compacted by heavy rains or form a crust after rain, thanks to this material. And, we haven’t had to lime; the bones from the fish carcasses provide enough calcium for us,” Herman said. All around, he feels that this is worth doing.

You can do this!

Herman had a few words of advice for those exploring the possibility of farm scale composting. “Get what is free and nearby. In my case, I had to haul the stable muck. Now, the wood chips are delivered and all I have to haul is the fish waste. Look around and see what is free or inexpensive. Something somebody else looks at as waste or as a problem, like stable muck. Keep this stuff out of the landfill!” he said.  “Try with a couple of cubic yards. Try the proportions, work out your recipe. If using horse waste, try to get fresh material, as old manure has lost most of its nitrogen,” Herman said.

“It’s a win-win-win when you build your soil. One year when you can’t make compost, it’s money in the bank, you have built a healthy soil… This is not rocket science; it’s so doable. Put it in your soil, heal the earth” he said.