Iris and Colin recently had an interesting Podcast discussion on the “Secrets of The Soil” that contribute to putting the super into Superfoods. We talked about the meaning of the old phrase “the answer lies in the soil” and explored the question “To Dig or Not To Dig”.
If you have already listened to the Podcast, below are some of the key points to take away, and if you have not heard it, here is the link
The Elements of Soil
Soil is composed of 4 elements: Water, Air, Minerals & Organic Matter, and to give you a good foundation for producing Superfoods, they should be roughly in the following proportions:
The first three elements are straight forward, but Organic Matter is composed of between 1 & 5 separate components and needs further explanation for us to be able to understand its role.
The 5 Components of Organic Matter
It is very important to understand that humus is not the same as organic matter.
and in fact it is common to have organic matter that does not have any humus in it. However, the word humus is often used interchangeably with organic matter, which creates a lot of confusion.
The Humus “Complex”
Further to the confusion regarding the word humus itself, there is also substantial confusion in popular and technical literature regarding the composition of humus. To achieve a clear starting point for further discussion, it is helpful to look at the various parts of humus from the perspective of chemistry.
It is best to see humus as a “complex” composed of 4 distinct substances, distinguished by their molecular weight and their solubility in acids, alkalis and water. This results in different degrees of stability and different roles for each substance individually, as well as creates a fascinating mix of roles as a complete “complex”. The 4 parts of humus are:
Fulvic Acid has a low molecular weight, is soluble in acids and alkali and water
Humic Acid has a medium molecular weight, is soluble in alkali, but insoluble in acid and water, has some resistance to microbial break down
Humin has a higher molecular weight, is insoluble in acid, alkali and water and is the most stable part, with the most resistance to microbial breakdown.
Humate is a salt or ester of humic acid
PLEASE NOTE: In recent decades, there has been some realisation of the importance of humus, and commercial products composed of parts of the humus “complex” have become available in the marketplace. But it is important to realise that, as in many situations, the whole is greater than the sum of the parts. And so with humus, we find that the parts are never as good as the whole “complex”.
With the framework of understanding that I have presented here, we can begin to focus on the practicalities that will help us to achieve the ultimate goal of creating a whole humus “complex”, as part of the organic matter element of the soil in our gardens, so that we can more easily grow our own quality, nutrient-rich Superfoods.
Yours for a healthy, living, stable, yet dynamic, soil.