My First Look at Terra Preta

Terra preta is a type of very fertile soil formed from human incorporation of charcoal into the soil. It is specifically referring to soil found in select regions of the Amazon Basin. I have done a little bit of reading on the subject to find out what makes the soil so great and how I can make some for myself. It turns out, making terra preta is not all that difficult provided you have plenty of wood or plant biomass to pyrolyze. But that takes time and makes plenty of smoke even with dry wood. With all this rain, I have to wait a bit until I have some nice bone-dry wood to experiment with. After thinking that I had to wait to make some, I remembered something: the old sugar shack/ pile of bricks and metal area in the woods. After digging a shovel into the soil, it looks like I found myself some New York style terra preta.

Terra preta soil looks and feels nice!

 Near the really dark soil, there is a pile of iron scrap metal. Some parts are from a barrel, and others look like shards from a large stove.

 There was a mound of soil near the scrap that I dug into, and found the soil to be very dark. The texture is very crumbly, soft loam. If my entire garden had soil like this, I would be blown away by the results.

Garden with poor soil

This is my squash garden that I will be using to experiment with. As you can see from this picture, the soil is a heavy clay. The soil does crumble well, but could use lots of organic matter.

One small load of terra preta was loaded into the back of a mule. The pile of soil was very stony, and there was a few large rocks. That large one in the corner was probably over 40lbs. I could tell that the stones had experienced very high temperatures because they were a lighter color and more brittle. The smaller ones broke easily to reveal a pinkish interior.

I mulched the garden with terra preta

Upper ground sweet potato squash started under lights has a good advantage.

Winter squash seedling with terra preta

The new squash seedlings have terra preta mounded around them as a mulch. I hope to put more loads of terra preta into the garden later in the summer, as well as make my own charcoal/biochar.