Everyone wants to have beautiful black fertile soil. The first settlers in the Amazon jungle were amazed at mounds of rich soil surrounded by extremely poor soils. They called them terra preta de indio or black earth of the indians. They are well known due to the discovery that biochar was largely responsible for their lasting fertility.
At Meadowcreek, we’re also growing vegetables in mounds using biochar. Our method also incorporates insights from Korean Natural Farming, indigenous Hawaiian horticultural methods, Square Foot gardening, double digging, Permaculture, and scads of research on healthy, productive soil.
Once complete, these mounds require little maintenance and produce bountifully year after year. All you have to do is clear some mulch away and plant some seed.
This easy and productive farming is possible only if you built the mound properly. Yesterday we built a new mound at Meadowcreek below the Resilience House. Here’s how we did it.
To build a mound you must start preparing several days before you actually put a shovel in the soil.The first key is biochar. A few days ago we made biochar next to our most fertile garden. The soils of this garden are healthy because they are teeming with a host of indigenous microorganisms uniquely adapted to our particular location and climate. When the biochar has cooled, we inoculate it with soil from our fertile garden.
Biochar is a perfect home for these indigenous microorganims to live and work. You need enough inoculated biochar to compose about 5% of the volume of the mound.
When your inoculated biochar is ready, the next thing you need is the right soil conditions at the site of the new mound. Soil which is too wet or too dry won’t work. Yesterday was a perfect day for mound building. The soil had been too dry to build mounds until it rained most of Wednesday. The soil soaked up all this rain with little run off. So Thursday we were pretty sure the soil would be perfect.
We headed out at 7 am to beat the heat of August in Arkansas. Meadowcreek Valley was filled with mist. We could barely see the cliffs and spires on the west ridge across the valley.
When we sunk the first shovel into the soil, we knew soil conditions were right. The complete shovel blade disappeared into the ground with just a little pressure. The soil where we are building mounds is clay with virtually no topsoil. It’s been a pasture as long as anyone knows. When it gets dry, this clay is too hard to even get a shovel to penetrate.
Since we are building in pasture, we have to clear away the tall grasses and legumes where we are going to dig. These are set aside to use as mulch later.
We are building this mound next to one we built earlier this summer. Each mound has an irrigation trench around it. We loosen a big chunk of sod with the shovel and turn it upside down in the trench. We break up this hunk of sod by hand getting lots of hand and wrist exercise. This sort of exercise, as Chinese traditional medicine has shown for 2500 years, is effective in alleviating all sorts of wrist and finger pain and of for general health.
The roots and stems from the sod are also placed aside for mulch. By stripping the soil from the sod by hand, the result is material which is fluffy and not compacted.
We continue the length of the mound–about 10 feet–shoveling out hunks fo sod and stripping the sod of soil by hand. When we get to the end of the edge of the mound, we go back along the ditch we have just dug and clean out the trench.
Then we start again turning over hunks of sod about two shovel blades deep and wide into the new trench where the roots and stems are separated from the soil. Enjoy all the creatures, especially grubs and worms that you turn up. Yesterday we found the largest earthworm I have ever seen. It should really love the new mound and help us create great soil. Sometimes you also find Indian arrowheads in this process, so keep an eye out.
This process continues until we have a 12 foot by 12 foot plot of fluffy soil newly liberated from the pasture grasses and herbs.
Now we are ready too bring in the inoculated biochar. We spread this over the new plot and then pull in soil from the edges and mix the pasture soil with the biochar, taking care to not step on the fluffy, soft mixture.
Another layer of inoculated biochar goes on top of the emerging mound and more pasture soil is incorporated from the edges. Once the pasture soil and biochar are thoroughly mixed, we begin tossiing shovel fulls of soil from the edges into the center. This continues until you have a rough pyramid.
Now it’s time to plant, but the mound is not really complete until you have used the vegetation you set aside to cover the mound between the new plants. If you are planting seed, you’ll wait until the seed have emerged before putting on the mulch around the new plants. If you are transplanting, you should mulch immediately.
An addition we like to add to the mound is a teepee composed of small diameter saplings tied together about four feet from the top of the mound. This provides a trellis for vining plants. When covered with vines, the teepee creates a microclimate on the mound which traps moisture on hot summer days.
When irrigation is needed, you just fill the trenches on each side of the mound ad let the mound pull the water into itself. We have a series of mounds whose irrigation trenches are all conected. This allow us to send water to all the mounds at once from a nearby pond.
The irrigation ditches on each side of the mound will collect vegetation and soil during the summer and winter. Clean them out in the spring and toss up on the mound to replenish fertility along with more compost and mulch.
I hope you got something out of this is a short sketch of mound gardening. To really learn how to do it, you need to come to Meadowcreek and build a mound. Head on up and we’ll teach you..It’s great exercise, much better than going to the gym.