Last week was “International Compost Awareness Week,” so compost was uppermost in my mind for much of the time. One major aspect that’s been on my mind is that, even though my six pet bunnies add a lot of old hay and bunny manure to my compost pile every week, there still isn’t enough compost for my whole garden, and my garden is not large.
I read once that the average WWII Victory Garden encompassed ~600 square feet. My vegetable growing space is just a little over half that. Remember — Victory Gardens during WWII provided about 40% of this nation’s produce at a time when that production was sorely needed. That is a huge amount of productivity!
The U.S. could do that again, if needed, but it would take a lot of compost. Maintaining a warren of rabbits in my garage is, apparently, not the answer to the question of where all the needed compost is going to come from. You may be asking — “why is compost needed in such large amounts?”
Part of the answer would lie in the brick-like consistency of Georgia clay in summer, or the non-absorptive properties of soils that are mostly sand. Even for conventional/chemical gardeners, compost can improve the physical properties of very poor soils.
Gardeners working in the kinds of subdivisions in which all the soil was rearranged by giant machines before construction even began, removing the topsoil and putting it who-knows-where, will totally understand what I mean by “very poor soils.” Many of us begin without any real topsoil at all! Compost improves moisture retention, nutrient availability, and biological activity in these soils.
For organic growers, abundant compost is basic to the whole process, with the “biological activity” part being of utmost importance, since without the underground microbes and their slightly larger associates, there would be no nutrients available for plant growth.
Even beyond the productivity gains that can come from nourishing the teeming billions of lifeforms underground, yet another reason to compost may lie in the ability of that compost to help move carbon underground. In my scanning of the morning news this past week, I read a surprising headline: “First time in 800,00 years: April’s CO2 levels above 400 ppm”. We all knew that was coming, but it does seem a little soon.
Couple that headline with an article that I had seen through Resilience.net, originally published at Yale Environment 360 — “Soil as Carbon Storehouse: New Weapon in Climate Fight?” — and compost is looking even more like the “black gold” that some gardeners call it, even though compost isn’t specifically mentioned in the article. Instead, it mentions other practices that could help store carbon in the soil:
“…replanting degraded areas, increased mulching of biomass instead of burning, large-scale use of biochar, improved pasture management, effective erosion control, and restoration of mangroves, salt marshes, and sea grasses”
Much further along, the article mentions the important role of fungi in storing carbon in the soil:
“…scientists from the University of Texas at Austin, the Smithsonian Tropical Research Institute, and Boston University assessed the carbon and nitrogen cycles under different mycorrhizal regimens and found that plants linked with fruiting, or mushroom-type, fungi stored 70 percent more carbon per unit of nitrogen in soil.”
Using composts and degradable mulches can do a lot toward welcoming the right kinds of fungi to a garden.
The article was aimed more at larger scale agricultural activities, but that doesn’t mean that gardeners can’t do their part to help out. If more of us are more intentional about what happens to the carbon that flows through our lives, it certainly can’t hurt.
This is my birthday month, and one of my best buddies, as an early birthday gift, took me to a book signing for Farmer D’s new book, Citizen Farmers (and she bought me a copy of the book, for Farmer D to sign!). One great aspect of the book is its focus on compost. Really, all gardening should start with compost, but most garden book don’t make that point so emphatically. Farmer D lists, right in the introduction, his citizen farmer basics, and number one on the list is “Make composting a way of life.” That sounds like a very good idea.