Building Ecosystems as a Side Effect of Growing Food
About a 5 minute read
Strongly interrelated and networked elements in a vegetable garden, an orchard, a community, or any other living system, are healthier and happier than isolated fragments of life subsisting alone and unmoored.
Let’s say that my family and I want to grow pumpkins.
At first glance it might seem that all we need to grow pumpkins is fertile soil and water.
We could just put fertilizer from a bag on the soil and set up an irrigation system. Right? Do we need anything else, to grow pumpkins?
A healthy food web, by definition, is complex
If we want our pumpkins to be healthy and bountiful, we need lots of things besides a patch of dirt, some fertilizer, and a hose.
Let's start with the teeming masses of small life forms we'll need, from pollinating insects down to the microscopic soil organisms that healthy plants depend on. (Unless we want to pollinate the flowers ourselves and to eat pumpkins fed purely on synthetic fertilizers.)
For these little critters to come to the party and stay to play, we need:
- shelter for the pollinators and other food sources for them when the pumpkins are not flowering,
- constantly replenished plant matter on the top of the soil that the soil critters can break up, pull down into the soil, and put to use, and
- a diverse community of living plant roots in the soil, since soil microorganisms rely on living plant roots at least as much as the plants rely on them1.
How many of these basic needs—for pollination, soil nourishment, and water, can we meet right in the pumpkin patch rather than having to import them?
The answer depends on how many other life-forms we can bring into the picture in harmonious ways.
And when we do that, how many other things can that same patch of ground yield, in addition to our pumpkins?
Who else can fit into this space?
Pumpkins are ground covering plants, but they don’t need much space under the soil. Sweet potatoes can co-exist with them.
That fills the ground level space, but what about the space above and below the ground covering plants?
Pumpkins and sweet potatoes can serve as a living ground cover under young fruit trees. Trees (obviously) will fill the space above our pumpkin vines, and they will also, less obviously, fill the space below the pumpkins and sweet potatoes with their roots. More roots means healthier soil, and deeper roots means all sorts of things from the drawing up of nutrients from deeper down, to the stabilizing and optimizing of water cycles.
Now in the same space we have three different types of food plants, an increasingly dense and varied network of living roots in the soil, and shelter and additional food sources for the pollinating insects when the fruit trees flower.
What else can we have?
Sweet potato vines tend to swallow everything in their path and could easily overwhelm young fruit trees. Luckily, pigs like to eat sweet potato runners. (We co-op with another family to raise pigs for happy, home grown pork.) Spoiled pumpkins, big tough old sweet potatoes, and overly enthusiastic sweet potato vines make up a good proportion of our pigs’ diet.
Are we done yet?
Nope, we're still not done. Some of our fruit trees are mulberries, which produce amazingly huge volumes of green, leafy growth in our warm season. So, throughout the growing season we’re constantly pruning the mulberries so as not to shade out things we don’t want to shade out.
What do we do with all those mulberry prunings? Mulberry leaves are an extremely useful animal fodder. Pigs love them, as do horses and cattle. And they can also be added to the mulch.
Which leads me into how we can get this pumpkin/sweet potato/fruit tree patch to grow its own mulch and fertilizer and even some of its own water.
Growing our own soil amendments and planting water
Between our fruit trees we plant leucaena and pigeon peas, which are both legumes2. Both these trees can be chopped and dropped for nitrogen rich mulch and they’re very useful fodders for cattle, goats, and probably also for sheep, lamas and such-like.
As well as legumes, we include other plants between our fruit trees specifically for the volume of mulch they can produce. Sugarcane, tiger grass, and large gingers all grow thick, tall and vigorous. They provide wind shelter to the young fruit trees and can be chopped and dropped as needed to lay mulch on the ground.
And we’ve begun to “plant water” in the form of bananas, Queensland arrowroot, and taros. These are mulch providers, but their other special talent is to hold lots of water and so help keep the system hydrated in dry times.
We planted comfrey too, although we don’t have nearly enough of it yet. Comfrey is an understory plant so it appreciates the shaded, moist environment under trees. And as you probably know, it produces abundant large leaves that are a highly nutritious addition to the mulch layer. Comfrey foliage is also a stellar livestock feed for pigs, poultry, goats, and cattle, as well as being a nutritive and medicinal herb for people3.
The connections make the magic
So. We started with pumpkin vines and now, crowded and connected and thriving and bustling and teeming, all in the same space, we have the beginnings of an ecosystem that:
- provides pumpkins and sweet potatoes, (which will fade out as the trees become more established, and will be replaced with fruit, so in that sense they're occupying a niche in time as well as in space),
- is home to birds and other critters like snakes, frogs, and lizards that appreciate the shelter and food provided,
- provides food and shelter for bees and other pollinating insects, as well as predatory insects that help keep pests down in our adjoining veggie garden areas,
- is somewhat self-mulching (the goal is for it to become fully self-mulching),
- is increasingly drought tolerant, and
- connects to our pig pasture, chicken coup, and house cow herd, via the food that goes to the animals and the composted manure that comes back to the fruit trees…
The connections between all these elements are where the magic lies.
It’s the connections and relationships and interactions that build holistic well-being into the equation. Strongly interrelated and networked elements in any system are immeasurably healthier, more resilient, more flexible, more full of vitality, than isolated fragments of life subsisting alone and unmoored.
A pumpkin by itself is just barely a pumpkin4. But when a pumpkin grows in an ecosystem, then it hums with the life-force and vitality that make food worth eating and life worth living.
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Did this post spark ideas for how you can create more connections between things that grow at your place? Have you combined different types of plantings to benefit each other? Please leave a comment below the Endnotes...
- Living plant roots are now recognized as a vital (perhaps the most vital) element in healthy soil biology. Among other important things they do, living plant roots exude sugars and compounds into the soil which are a major food source for the soil food web. Without living plant roots, the more diverse the better, present in the soil all the time, soil health collapses. For more on this, see “Maximize Living Roots,” “Going Underground: How Roots Could Hold the Answers to Our Soil Health Problem,” and this excerpt from the book, Dirt to Soil.
Legumes have a symbiotic relationship with a type of bacteria called rhizobia. Rhizobia are housed in nodules on the roots of leguminous plants, and convert atmospheric nitrogen (which plants can't use) into ammonia, which can be taken up by the plant and converted into nitrates, important for plant growth.
The nitrogen is then shared around with surrounding plants, particularly when the legume is pruned and its foliage is added to the mulch, when it drops leaf litter, and when any of its roots die and decompose in place.
- Caution: read up before you consume comfrey leaves, and do not consume comfrey roots.
- I wrote about this recently in “Supermarket Food is Like a Tiger in a Zoo.”