Back to Eden: Soil pH

This is the end of our first year doing the Back to Eden garden and I wanted a tangible way to guage the results of the soil condition.

I decided to test the soil pH with a very rudimentary and simple experiment: vinegar and baking soda.

The concept is simple; alkaline soil will react in the presence of vinegar and acidic soil will react in the presence of a baking soda and water solution. There are probably plenty of more educated people than me who would criticize the proposed experiment as well as the Back to Eden style of gardening. After all, it’s completely counter intuitive; wood chips burn up your plants, they make your soil acidic, they’re dry, they attract termites, the weeds still come through, etc… We’ve been taught by the “wise” to trust what we are told rather than asking for ourselves and seeking the answers through research and experimentation. I decided last year to ignore the people who disagreed with me, and this time, I’m glad I did.

First we collected soil samples from the Back to Eden plot, and then from the top of our swale which is uncovered (no wood chips) and unaltered with organic material or compost. I call the unaltered soil “raw.”

Just looking at the samples you can see the difference in color and composition. The raw soil is predominantly clay which compacts easily into little balls. The Back to Eden soil is much richer in color and is extremely loose and fine.

Then we prepared baking soda and vinegar test jars

We first added each of the soil to their own jars of vinegar. Neither soil reacted with the vinegar.

Then we mixed some of the soil with baking soda. In order for this test to show any results, the dry mixture has to be turned into a liquid solution by adding pure water. Baking soda in the presence of water has no reaction because the water is neutral (pH 7). However, if the soil is acidic, the addition of water will cause the acidic “mud” to react with the alkaline baking soda. And this is where things got interesting.

When we added water to the Back to Eden and baking soda mixture, nothing happened. The water was absorbed and a nice dark mud was formed. But, when we added water to the raw soil and baking soda, the mixture fizzed and bubbled! 

By this experiment, we were able to show that after a year of Back to Eden preparation, the acidic soil that characterizes the vast majority of our land (and much of East Tennessee in general) was effectively neutralized without the use of tilling, lime, or any other chemically altering product. Simply by the layering of organic materials such as leaves, grass clippings, and vegetable compost as well as composted chicken manure on top of the soil, and irrigated only through natural rainfall. No digging, no tilling, no paying for chemicals or additives or fertilizers. Amazing right? I too find it hard to believe but the concept is incredibly simple. And as Scripture teaches, it’s the simple things that are most often the most difficult to grasp.

Check out this video of our baking soda test.