Carbon dioxide (CO2) is one of the many greenhouse gases that in increased amounts contribute to global warming and climate change that we are currently faced with in Namibia and the world at large. Soils and plants store a lot of carbon, nearly twice the amount found in the atmosphere. This stored carbon in the soil acts as the basis of soil fertility that promotes plant growth, the biological and physical health of the soil and buffer against harmful substances. The whole idea is to build up carbon in the soil, while drawing down CO2 in the atmosphere through improved soil management.
My interest in this topic rose from the situation of poor soil quality we have at my home in the northern part of Namibia. I say the soil is of poor quality because it contains very little organic matter and it is easily eroded away by wind or water. Thus, very few crops are produced from these soils. As a bachelors graduate in the field of agriculture, my interest has always been food production and ensuring food security. Therefore, it is very important to conserve the soil to tackle issues of food insecurity. The carbon dioxide released from the soil and plants into the atmosphere leads to an increase in the amount of greenhouse gases, leading to climate change. This is another issue that we are faced with. I think it is only by starting with small actions such as soil conservation that we start to address the issues of climate change and mitigating its effects. Climate change was not really something I paid close attention to in the past, not because I did not know what it was, but because I did not know the seriousness and how climate change is affecting our daily lives.
Veld fires are one of the factors contributing to a loss of soil carbon. Earlier this year, there was a report in the news of the Okongo conservancy that burned down. My thought was, how will this affect the productivity of the conservancy? Productivity in this case is in terms of grass, shrubs and trees in the conservancy that support the lives of animals in that area.
A study by Christina Frame in 2010 reveals that a disturbance of soil by veld fires reduces soil carbon by 59%, resulting in it being lost into the atmosphere and reducing the soil’s fertility and health, thus affecting its ability to sustain plants growing on it. Veld fires occur outside the build-up of urban areas specifically in forestlands and grasslands and have a potential of running out of control. In Namibia, veld fires have become a serious problem and remain a challenge especially in forested areas.
How do veld fires affect soil carbon?
Imagine a soil without organic matter (this is the first layer of the soil profile). That soil is lifeless. Disturbances by fire destroy this top layer of the soil, and with it, the organic matter content. Soil is known to be ‘a pool’ of carbon and fires result in reduced numbers of microorganisms living in the soil to decompose leaf litter. These organic organisms are responsible for holding and storing carbon in the soil and thus improve soil fertility and health.
The infographic below is a representation of how fire leads to an increase in atmospheric carbon dioxide and a reduction in soil cover over the years. The more trees and soil cover there are, the less carbon in the atmosphere and vice versa.
I recently watched a National Geographic documentary titled ‘Before the Flood’, were Lindsey Allen, the Executive Director of Rainforest Action Network talked about how veld fires are worsening climate change. An example was given of Sumatra rainforest in Indonesia being destroyed and burned down intentionally to create palm oil plantations. It is really sad to see such a selfish act that benefits a few people only (the palm oil processing companies) but with far reaching consequences for humanity.
The benefits of soil carbon
There are many benefits to soil conservation which maintains its carbon content. These include:
- Helps in mitigating the effects of climate change. This means that if more carbons are stored in the soil, there will be less carbon in the atmosphere which will help reduce global warming which leads to climate change.
- Improves soil health and fertility. This means that the amount of carbon stored in the soil as a basis of soil fertility promotes plant growth, the plant structure, as well as the biological and physical health of the soil.
- Soil carbon increases the productivity of crops in agriculture, trees in the forests and supports the ecosystem services or the benefits that humankind receives from the ecosystem. These may include provision of food and water, regulating climate and control of diseases and supporting nutrient cycles.
Call to action for soil conservation
Soil carbon plays an important role in maintaining soil fertility and health and in helping to mitigate climate change effects. It is therefore the responsibility of us all to take care of the soil by reducing the occurrences of fires and other harmful activities to the soil quality. Veld fires are usually unavoidable or preventable because in most cases, they occur naturally by natural causes such as lightening. It is for this reason I think we should mainly focus our attention on maintaining and increasing carbon in the soil, rather than trying to prevent naturally occurring veld fires. Below are some of the practices one can do to increase carbon in the soil:
- Conservation agriculture practices such as minimal tillage
- Improving crop management practices such as crop rotation
- Improving grazing management practices such as rotational grazing for better managed rangelands
- Adding organic materials such as compost and manure into the soil to increase the amount of organic matter in the soil, leading to more carbon stored in the soil
- Maintaining and conserving ground cover
- Actively contribute to reforestation, especially planting indigenous trees
It will make a very big difference by practising even just one of those actions.
Let me conclude by reciting a very educational and important quote by the Food and Agriculture Organisation of the United Nations (FAO 2015), “Soil destruction creates a vicious cycle, in which less carbon is stored, the world gets hotter, and the land is further degraded”.
About the author
Saija-Kristophine Kristof is a Bachelor of Agriculture Honours student majoring in Agri-business, at the Namibian University of Science and Technology (NUST). She is currently a Project Intern with the Environmental Awareness and Climate Change Project hosted by the Hanns Seidel Foundation Namibia. As a bachelors graduate in the field of agriculture, she is very passionate about soil conservation as part of food production and is very optimistic about the future of Namibian food security.