The link between soil health, carbon and healthy plants
We’ve always stressed how important soil health is to plant health, but our friends at Madumbi are the experts so we asked them to give us a more in-depth understanding of carbon.
Fact: The nutrient content of a plant’s tissues is directly related to the nutrient content of the soil, and its ability to exchange nutrients and water with plant roots. (FAO – Food & Agriculture Organization of the United Nations fao.org/ soils-2015)
In simpler terms, plant health and soil health go hand-in-hand. South African gardens are made up of a wide range of different soil types, each with their own properties, benefits and challenges. Soil is the foundation of a good garden and as our understanding of soil health grows so too does the priority of building soil.
What do we mean by building soil?
To build a house you need bricks, cement and a team of builders. We all understand that – but how do we as gardeners go about building soil?
At Madumbi, our reference point starts with nature, where soil is formed primarily in two ways:
- Physical and chemical: The weathering of rocks, into smaller and smaller fragments that ultimately lead to soil formation.
- Biological: The decay of dead plant and animal material to form organic matter.
These processes have been taking place for millions of years, and will continue to do so. However, as the global population grows, so does the pressure for healthy food production and healthy soils. The natural soil-forming processes simply cannot sustain our growing planet – we need to do our bit by protecting our soils and building soil in our individual capacities, whether in the garden, on the farm or in nature.
The importance of carbon in soil
The carbon cycle is a fundamental part of life on earth. See above.
CO2 is probably the form of carbon we are most familiar with, but this only makes up a small portion of the gases in our atmosphere (0.04%). Significantly more carbon is stored in soils as ‘soil organic carbon’ (SOC), which is more commonly understood by gardeners as soil organic matter (plant and animal matter in various stages of decay).
Soil carbon is the backbone of soil fertility. The more carbon in the soil, the healthier the soil, and as a result the healthier the plant growth will be.
What are humates and humic substances?
EcoBuz HumiGro is a carbon-based soil conditioner made from humate granules. Humic substances make up the major organic component of the Earth’s soils and sediments, created from decayed biomatter. After plants die, their organic biomatter is degraded by microorganisms in soil to eventually produce humus. Humus-rich soils form the basis of healthy plant growth. Humates are the active ingredient in humic substances.
Adding humates to the soil adds carbon to the soil. In nature, nothing happens in isolation, and the additional carbon promotes existing microbes, enhancing microbial population growth, which results in improved microbial activity and decay (supporting the biological processes needed to build soil).
Humates have the following key benefits:
- Feed beneficial micro-organisms (provides energy and nutrition).
- Increase root respiration and formation.
- Enhance nutrient absorption.
- Improve soil aeration and water retention.
- Decrease water loss and reduce leaching.
- Enhance the performance of fertilisers.
- Act as a buffer to harmful substances in the soil.
Think of humates as a concentrated version of compost that forms part of a holistic approach to soil health management.
Humates and compost contribute to the building of soil but because HumiGro is a more concentrated version it has a significant impact on the rate that soil and organic matter is improved.
Soils need to be viewed as a living, symbiotic ecosystem. While this article focuses on the importance of carbon, the basis of soil fertility, it is important to remember that carbon is just one cog in a highly complex system.