I’m not the type to feel excited by compost. That being said, I have been proved to be very wrong about my ideas about composting on a farm. I imagined a large pile of waste, stacked high, disordered, and decided without well-thought-out plans. So you may be wondering, what was it that lured me to embark on a two-hour tour of Frog Hollow Farm’s compost system? The answer — compost tea.
As a lover of fine teas, I had to know, “what is compost tea?” “How can I get my hands on this unattainable tea?” I was guided to a scientist working on the farm – to find him, Farmer Al told me “Just look for the guy with the goofy hat.” Once I found Christophe, I was off on a ride across the 133-acre farm. To understand compost tea I had to wait. First, I started with soil.
Christophe explained the beauty of soil as an alive microorganism with a structure. And that, the soil on Frog Hollow Farm is clay from the San Joaquin River that ran through years ago. The nature of this soil is believed by farmers to have been preserved by the warm weather and cool nights – enabled by nearby Mount Diablo blocking Bay Area fog and from evening winds rolling in from off the Golden Gate Bridge. I had to admit, there was something mystifying about the way he was describing the ‘legendary’ nature of the land.
Next, adjacent to an acre of peaches, I learned that compost provides valuable nutrients to soil and plants. At the simplest level, it is the process of leaves and food breaking down into the soil. However, on the other side of the scale, it is a highly monitored process, with supervision over the moisture, air and carbon-to-nitrogen ratio. By monitoring the feedstock (compost pile), the natural process of decomposition is accelerated. And although a person is typically turning and measuring the feedstock’s progress, the ones who are truly ‘doing’ the composting are hundreds of tiny microorganisms.
Christophe showed me a laminated chart of the organism food web. Arrows pointed showing that bacteria uses carbon and nitrogen from the feedstock to grow and reproduce followed by excretion of nitrogen, phosphorus and magnesium. With enough carbon and nitrogen, the oxygen-loving (aerobic) bacteria will flourish and leave the microorganisms that are less productive in an oxygen-rich environment behind. Larger macro-organisms like worms, nematodes and flies help smaller organisms by chewing the feedstock down. Worms are especially important since they leave behind ‘castings’ that are equivalent to their weight each day and consist of nitrogen, calcium, magnesium and phosphorus.
Upon learning about the contents of the feedstock, I started feeling like Frog Hollow Farm must be the most luxurious place for a tree. The compost is made from a caliber of food that can be found at fancy restaurants (just a different grade). What is the recipe for Frog Hollow Farm feedstock? Infamous Bay Area-based Blue Bottle Coffee grounds and old Frog Hollow pastries are the “cherries” on top of the concoction. The base of the mixture is fruit and leaves (or other “young things”), horse bedding from across the street, and the farm’s wood chips.
We arrived at the end of the Frog Hollow Farm lot where piles from the feedstock are monitored for two main qualities – moisture and oxygen. A series of long feedstock piles run through the area in perfect piles. To control oxygen quantities within the pile, the woodchips are at a size where the air can flow in. With the right amount of air, the bacteria are happy and can grow and secrete quickly. Another way to make sure that all parts of the feedstock are getting air is to turn the piles (with a very impressive machine, I must add). Frequently, the machine that turns the piles is used simultaneously with a watering. Every day optimal moisture and oxygen levels are measured to ensure that at least 40% moisture and temperatures between 90 and 140 degrees are maintained.
As we wrapped back around the farm we started heading for the compost tea. Very large netted tea satchels are stacked up near the compost. I learned that compost tea is made from steeping compost in water in the satchels and that the remnants are used to spray on leaves and soil. This process replaces chemical-based fertilizers, while increasing plant growth and providing nutrients to plants and the soil.
I feel fortunate to be taken on Christophe’s tour of Frog Hollow Farm. It’s amazing how farming requires a combination of science and trial-and-error in an effort to create the best recipe for the land. Composting is a perfect example of the collaborative effort needed with farmers, critters and scientists. Frog Hollow Farm is willing to put in the effort to adjust and create a better composting system and will continue to experiment until the recipe is perfect.
- Katie Gronsy
Katie Gronsky is a Certified Health Education Specialist who has a passion for local food and fresh fruits and vegetables. She works to create a more just and sustainable food system for all and loves connecting food and community, whenever possible.