The element carbon, with the symbol C and atomic number 6, is the seventh chemical element in the biochemical sequence of essential plant nutrients. It is the chemical basis of all known life. Plants absorb carbon from the atmosphere in the form of carbon dioxide. In the presence of phosphorus the carbon is prised lose from the carbon dioxide so that it can combine with water to make sugar and release oxygen. The sugars are then taken up in the sap and cells of the plant under the direction of potassium.
With carbon so freely available in the atmosphere, it doesn’t come to mind for most conventional farmers. However, this element also plays such a vital role in the soil. Humus, the organic matter in the soil is a major source of organic carbon which supports the communities of micro-life in healthy soils. Holistic mineral management takes this into account as plants are dependent on abundant micro-life to make the full spectrum of minerals available to them.
Unfortunately, South Africa’s agricultural soils are horribly deficient in humus. Conventionally-used chemical fertilisers, herbicides and excessive regular tillage burn up the humus in the soil. Some herbicides that serve as microbial food promote unnatural spikes in micro-life populations that consume, and so deplete the available humus.
Without humus in the soil other minerals are easily leached into water systems. I will be posting a new series of articles on the subject of humus that will explore humus creation and humus management which is so important in holistic agriculture.