This guest post was contributed by Nena Johnson, Public Programs Director at Stone Barns Center For Food and Agriculture.
About a week ago, Stone Barns Center for Food and Agriculture welcomed 35 farm interns from around the region for a CRAFT visit. CRAFT (Collaborative Regional Alliance for Farmer Training) is a network of farms in the Mid-Hudson and Lower Hudson Valley that offers field trips for interns, apprentices, and staff throughout the growing season – giving them a glimpse of the varied types of farming going on nearby. Typically the two-hour visits end with a potluck dinner, so in addition to getting some great technical content in, it’s a nice way to meet other like-minded young farmers from the area.
For the Stone Barns visit, our focus was compost. Gregg Twehues, Director of Nutrient Management at Stone Barns, started us off in the courtyard with an overview of composting basics. The recipe for compost is one of the simplest on earth: Carbon + Nitrogen / Time = Compost! The carbon ingredients are your “browns” – leaves, wood chips, shredded cardboard (more on that later); the nitrogen ingredients are your “greens” – table scraps, lawn clippings, garden material, and animal manures. A ratio of 30:1, Carbon:Nitrogen, ensures active aerobic, and timely composting. The materials begin to decompose, giving off heat and breeding good biology – critters that turn old leaves, food waste, manures, etc., into the “black gold” farmers spread on their fields and gardens as a natural and healthy fertilizer.
To see this in action, Gregg led us down to the poultry processing facility. Our destination was the O2 forced-air composter right next to the barn. The large cement box – divided into three bins and covered with a tarp – was odorless. Gregg explained that as plans for our on-site poultry slaughter ramped up, it was clear that we’d have a lot of remnants and mortality to deal with (think beaks, blood and feathers). Our existing windrow composting operation wouldn’t be the most efficient way of treating those materials. Enter the forced-air system! Between the floor and the waste material is a grate, leaving a gap of a few inches for air to permeate. A vent on the floor of each bin is connected to a valve on the outside, and at an interval of three minutes every 20 minutes, air blows into the bin from below, helping to speed up the decomposition process. With this type of system, we’re also able to include post-consumer food waste (compostable napkins, plates, cups, straws, and utensils – plus any unfinished food), helping to close our waste-management loop on the property.
So that takes care of our “greens” – now for the “browns.” Like any other business or organization, Stone Barns has a lot of things delivered in cardboard boxes every day. Unlike most others however, we shred our cardboard and toss it in with our Berkshire pigs! They use it as bedding and they also enjoy giving it a chew now and then. The resulting material is a great carbon source for the O2 system. We add that, plus wood chips and mulch, to the mix and a short 35 – 40 days later, we’ve got some lovely almost-compost.
Next, that material is carted out to a 1.3 acre pad in the woods where we’ve set up compost windrows – long, narrow rows of compost in various stages of finishing. Which brings us to the second part of the CRAFT tour.
The majority of the windrows are part of our vegetable compost operation – no poultry bits here! It’s made up of pre-consumer vegetable scraps, lawn clippings, animal bedding, and green materials from our produce operation. As it breaks down, it’s laid into long windrows and covered with heavy felt-like blankets. Periodically, the material is turned (using an attachment on our tractor) to ensure healthy, aerobic decomposition. The temperatures in the middle of each pile hover around 140 degrees – turning the material guarantees that every last morsel hits that magic 140 mark, necessary for breeding good biology. This area was noticeably odorless as well. Gregg gave us a great tip – if your compost stinks, something’s wrong. Healthy compost shouldn’t smell like much at all. After several weeks, the material passes through a screener to weed out anything that might not have decomposed entirely (e.g. bones), and the result of that process is gorgeous, finished compost.
Next we walked in among the windrows and were invited to sink our hands and arms deep into the pile, feeling the intense heat and seeing a little steam rise out. That right there felt like a great finale to a fact-filled two hours, but Gregg wasn’t done with us yet! He hopped on his tractor and proceeded to turn half a windrow – compost and steam flying – as the crowd erupted in applause. That’s how you end a compost class.
The finished material ends up in a few different places: the O2 compost goes back out on the pastures to keep the Stone Barns grass lush and healthy season after season; the vegetable compost is used in our greenhouse, vegetable fields, and gardens; and the large remainder of that is bagged for sale at our Farm Market and several nurseries in the area. Gregg also sells in bulk to landscapers.
Hands dirty with compost, we headed back up to the courtyard to dig into a potluck feast of seasonal goodies prepared by all the visiting farmers and local beer donated by Captain Lawrence Brewing for the occasion. We spent almost two hours eating, talking, and enjoying sitting out under the night sky.
The CRAFT season is a little more than half over – if you can, join us on one of the next tours – you’ll get the chance to know a farm (and a few farmers) better than before! View the complete CRAFT schedule.
Nena Johnson is Public Programs Director at Stone Barns Center For Food and Agriculture in Pocantico Hills, New York.
This entry was posted on Wednesday, August 4th, 2010 at 9:46 pm and is filed under CRAFT. You can follow this blog through the RSS 2.0 feed. Responses are currently closed, but you can trackback from your own site.