Soil Microbes and Compost Tea: helpers for any organic farm

We've been having a very dry few years on our Fort Wayne uncertified organic farm. Let's time travel back to 2024. After a very dry summer, we finally got a bit of rain over a weekend in September: around 3/4” all told. Seems like a fever dream with all the rain we've been getting this spring, but this was our reality for about two years. 

This was bad news because, newsflash: plants need water to grow. Irrigation solves this issue during a drought, but one of the main concerns during drought is plant nutrition. Conventional fertilizers developed using fossil fuels work so well for two reasons:

1) they’re water soluble and
2) they’re designed so plants can easily absorb them.

​Plants can be fed these fertilizers during irrigation, and this is how modern operations can grow lots of produce in little to no soil. Organic fertilizers need an intermediary—soil microbes—and take a bit longer to work.

Example: Alfalfa and Nitrogen Fixing

As an example, alfalfa meal is rich in nitrogen (one of the three main nutrients plants need). However, plants can’t just process the stored nitrogen; they rely on microbes to break it down into a form that they can use. The breakdown process is actually quite complex and relies on a series of different microbes, all which have a role in “fixing” nitrogen into a usable form (this article has a lot more information if you are interested).

The Problem with Droughts and Soil Fertility

Now, back to the drought theme. During an extended drought, soil life quickly plummets. Water is life, and if there isn’t moisture in the soil, microbes go dominant as a survival technique. That “after-rain” smell of earth that we all know is really just the soil springing back to life—the result of microbes rapidly reproducing. Just a handful of healthy soil contains billions of microbes, many of which plants rely on to help feed them!
​
So, simply put, the fewer microbes in the soil, the more stress our vegetables are under and the harder it is for them to get the nutrients they need. Even if their rootzone is moist from irrigation, the soil as a whole is barren, making nutrient cycling difficult.

A Fort Wayne Organic Farm Fix: Compost Tea

One way I try to add life back to the soil is through compost tea. Essentially, this is just compost “brewed” in aerated water. The conditions are perfect for the microbes in the compost to rapidly multiple over a few days. The tea is then sprayed directly on the plants and soil to help replenish the lost microbe population. In a way, this stretches the compost without the cost and labor of applying compost to the entire farm.

Compost tea application has been a weekly routine this year. See the photo above for my “high-tech” set up. You'll find such "tea" pretty much on any Fort Wayne organic farm (or organic farms elsewhere).