By guest blogger Coach Mark Smallwood, Rodale Institute executive director
Just as the statement “milk is milk” is patently not true, so is the idea that all compost is created equal. Dictionaries and encyclopedias simply define compost as “rotted organic matter made from decomposed plant material.” And while piling plant material in a heap and waiting long enough might result in rotted organic matter, it would still be a far cry from the truly fertile whole-food nutrition on which plants will thrive.
Whether gardeners and farmers make compost themselves or get it from an outside source, there is a wide range of practices that can lead to the final compost product. What matters in the end, though, is whether it will help your plants flourish—or might it actually hinder the growth of your garden?
Simple recipes usually result in a mildly fertile and generally decent compost that gardeners can make without too much effort or background knowledge, a kind of Compost 101. But for master gardeners or farmers whose livelihoods depend on producing the best crop they can, there are few “best practices” resources out there for tried-and-tested master-level compost production. From community and commercial composting facilities to farmers and gardeners nationwide, what you most often see is the Compost 101 recipe on a variety of scales.
Here at Rodale Institute we’ve been making compost for decades. We already know that compost improves soil structure and can increase the water-holding capacity of soil—meaning even when there is a shortage of rain, gardeners and farmers have a better chance of still growing a good crop. Compost can also keep the soil pH in balance without additional amendments.
But it wasn’t until recently that we started to look a little more closely at our compost. We actually began to take a look at our compost under the microscope and discovered that not even all of our compost was created equal.
What breaks down organic materials into compost and creates a nutritious support system for plants is the microbiology living in the compost—the living, breathing, eating, and expelling organisms. Bacteria, fungi, protozoa, nematodes, and microarthropods all have a part to play in making top-quality compost. And all of these creatures need to collaborate in the right balance. It’s not just a matter of who’s in your compost, but how big their families are. Different plants require different amounts of each type of microorganism. For example, weeds like to grow in soil or compost with lots of bacteria. Woodland plants require more fungi.
So the next generation of compost questions we are trying to answer are about digging in a little deeper, improving upon the solid base of general information we already have about compost and making the potential benefits of compost more of a sure thing. What does soil disturbance or compaction do to the balance of microorganisms? How do cover crops select for particular microbial communities? Can we reduce or even eliminate weeds by tweaking the types of critters in our compost?
We’re looking at the compost recipe all farmers must follow to be USDA certified organic and identifying how to improve the process. Basing the recipe on temperature rather than a prescribed number of turns means following the biological processes of the microorganisms—turning and aerating the compost piles when it is beneficial to them and not detrimental.
Taking the idea a step further, if we can manipulate the microbiology of the compost so it is ideal for a specific crop plant, we should be able to build a compost recipe matrix that coordinates with what you want to grow. This is really Compost 401. It’s time to figure out how to make compost live up to its potential every time. A lot of people make compost. The question is: What’s really in it?
Next post, I’m going to talk about how these microbes in compost and soil make nutrients available to plants, aka nutrient cycling, aka “cake and cookies.” Stay tuned.
Coach Mark Smallwood has been dedicated to environmental sustainability, efficiency and conservation for decades. Since joining Rodale Institute in December 2010, he has brought heritage livestock back to Rodale Institute’s 333-acre farm, expanded and enhanced Rodale Institute’s research efforts, as well as launched “Your 2 Cents,” a national campaign to support and promote new organic farmers. In recognition for his sustainability efforts, Coach was chosen as a messenger for Al Gore’s Climate Project presenting to over 15,000 people on the effects of Global Warming. Last, but certainly not least, as a long-time organic farmer and biodynamic gardener, Coach has raised chickens, goats, sheep, pigs, and driven a team of oxen.