As you may have learned, compost is a big deal at the farm. It is the foundation of our soil fertility program; helps with water retention; and is part of our pest management strategy. By the close of 2015 we will have produced between 3,000-4,000 tons of our thermophilic compost. We apply our thermophilic compost with a mechanical spreader that broadcasts a thin layer of compost under the trees, between the trees and in the wheel rows of the orchard.
Our thermophilic compost is a win for the farm because it allows us to transform large amounts of organic matter that would otherwise be waste into a vital product for the orchards soil health. Every year we turn tens of thousands of pounds of fruit too damaged or ripe for the kitchen and lots and lots of woody material from pruning and thinning our 30,000 trees into compost.
In addition to our thermophilic compost system, we have been steadily developing our vermicompost program. Christophe, our compost master, initiated a fledgling worm compost experiment in 2012. The first system was very primitive – a few plastic storage tubs in Becky and Al’s yard. We soon discovered that Brentwood was too hot for the worms to be outdoors in these small plastic containers. We purchased a wigwam, a heavy grade 1⁄2 ton capacity plastic bin made especially for vermicompost and placed it inside a shed. Our worms were happy in the wigwam but the amount of compost we could create was limited to about one ton of vermicompost a year.
In 2013 we wanted to increase our vermicompost production capacity so we created two outdoor worm beds and two “crocodile pits” , worm beds lined by concrete blocks under cover of another shed. To populate these compost areas we purchased 25,000 worms from Sonoma Valley Farm.
For the last two years, there has been a lot of trial and error in learning how to best manage these systems to keep our worms producing offspring and decomposing organic matter. Temperature is key to production. The ideal temperature for the worms is between 65-75F. In the summertime when temperatures in Brentwood break 100F, Christophe has made many an emergency run to buy bags of ice to poor over the worm bins and beds to keep the worms cool and prevent mass die off. He’s since learned he doesn’t need to do that.
The worms will just borrow deeper into the soil and reproduction and decomposition will come to a halt until temperatures cool. We are also learning how valuable vermicompost is on our farm. Stay tuned for more on our vermicompost in January!