Currently I am experimenting with using liquid fertilizers. While I like the results, it makes me dependent on an external resources. So I have been looking into methods of manufacturing my own.
The first method I looked into was compost teas, both non-aerated (NCT) and aerated (ACT). These are made by steeping compost in water and allowing the mixture to ferment for several weeks. The first step dissolves nutrients from the compost and the second uses those nutrients to grow microbes. Various forms of sugar can be added to aid fermentation. The difference between NCT and ACT is whether air is pumped into the solution during both steps.
In general, the benefits of both NCT and ACT do not outweigh the drawbacks. The growth of microbes shouldn’t change the amount of nutrients available. In addition, there is no way to ensure the product isn’t contaminated with bad microbes. Aeration is supposed to deter this, but there is some data that shows that it might make it worse.
The second method didn’t have a good name, so I am going to borrow one from herbalism and call it Plant Maceration. This method is identical to the first step of the previous. In this case, plant material (compost could also be used, I suspect) is combined with water for three days to allow the nutrients to dissolve. After this it is used immediately at a 1:1 dilution with water. This reduces the growth time of microbes.
The attempt to identify the second method has provided two more potential methods: infusion and decoction. An infusion is similar to a maceration except that hot (but not boiling) water is used to steep. A decoction uses actively boiling water to extract the nutrients.
So the next step in the research will be to perform my own (rudimentary) quantitative analysis. This will mean preparing one batch of each (maceration, infusion, and decoction) and running NPK tests. Of course this will mean researching into how to conduct these test. Always more to learn.