We are celebrating World Soil Day with a chat with Dr Corrie Swanepoel from the Soil Science Society of South Africa.

We are celebrating World Soil Day with a chat with Dr Corrie Swanepoel from the Soil Science Society of South Africa.

Dr Corrie Swanepoel  is  a soil scientist and a researcher, and for the past 15 years, she has been working at the Agricultural Research Council. Dr Swanepoel is also board member of the Soil Science Society of South Africa. I completed my PhD a few years ago, and my research focus is on soil fertility, mainly soil organic carbon, nitrogen and management practices that can influence soil health. 

1. Greetings, Dr Corrie Swanepoel. First, thank you for taking the time out of your busy schedule to sit with us for this interview, especially since the world is celebrating World Soil Day. To kick off the discussion, what does soil mean to you?

Well, thank you to AMC for featuring the Soil Science Society of South Africa (SSSSA) on World Soils Day. You are kicking off with an almost philosophical question. As a soil scientist, soil represents different things to me. Soil is life. It is a complex mix of organic and inorganic substances. The soil is interesting, and the soil is beautiful. 

2. Soil is misconceptualised in society. We all think we know what soil is and understand its importance. How would you explain to someone what soil is and why is it important?

Soil is such a cross-discipline topic. It overlaps with disciplines such as geology, agronomy, botany, ecology, climatology, economics and mechanics. You can specialise in so many things as a soil scientist. I focus on soil nutrition; others focus on soil physics, soil chemistry, soil biology, pedology or even engineering. Soil is central to issues such as crop production and food security. We use soil to build with and build on. Soil influences the type of vegetation and the carrying capacity of wild animals, so we also need to understand it in ecology. So really, it is the backbone of everything we do. 

3. Soil sustains life by providing food in the form of essential minerals and nutrients. Soil pollution and contamination have been a growing problem globally. We have seen that soil pollution can be caused by companies or by people in general. How would you describe South African soil pollution's current state and challenges?

Soil pollution is one issue on the topic of soil degradation; there are other issues, such as erosion, acidification, nutrient mining and compaction. Depending on the area and human activities, either one of these is the most pressing issue. Soil pollution specifically is mostly associated with mining, agriculture and other industries. Soil pollution can come in different forms, from heavy metal contamination, salts or organic compounds. The solutions are as diverse as the types and origins of soil pollution

4. Hydrology is the study of water movement through the soil. Please tell us more about what hydrology is and its importance of it.

Soil plays a central role in the hydrology cycle. Water is filtered through and stored in the soil. Other processes include drainage, evaporation and transpiration. Soil physicists study the movement of water through the soil, which is influenced by the size of soil particles and the density of the soil; these create openings through which the water can flow. A clue that the soil is well drained is the red colour. Iron in the soil reacts with oxygen in the air and forms a ferric iron oxide which is red in colour. In soils with poor drainage, water tends to be stagnant, and due to the lack of oxygen, reduced iron or ferrous iron oxide is present that is more yellow or grey in colour.

5. I noticed that you're an advocate of soil organic matter. Please tell me more about it and when it can be applied.

Soil organic matter is very closely linked to soil fertility. Soil with a high percentage of compost is usually darker, fertile, and more resistant to erosion. Organic matter also sustains the food web in the soil, which ranges from microbes to mammals. A lot of research focuses on how to increase organic matter in the soil to help sustain healthy and productive soils. Building up organic matter in the soil also positively impacts climate change. Organic matter has high carbon content, and sequestering carbon in the soil, means it is removed from the atmosphere, which can contribute to global warming. So yes, we love organic matter in our soils.  

6. As you know, we are celebrating World Soil Day today, and this year's theme is "Soils: Where food begins" what does that mean to SSSSA?

The SSSSA creates a platform to share ideas and resources, and one of the biggest focus points of our members is agriculture and food production. This year’s World Soil Day theme fits perfectly with our mandate.  

7. South Africa has a growing challenge with a youth unemployment crisis. How does SSSSA support young soil scientists, and how do you empower young people to pursue a career as soil scientists?

The SSSSA promotes and protects soil science as a discipline. And young members are definitely the future. Students are encouraged to become active members of society, they have special membership rates, and we also provide a student bursary each year. Also, we host a Combined Congress each year and publish a journal (The South African Journal for Plant and Soil). For this, three agricultural societies join forces, the SSSSA, the Southern African Society for Horticultural Sciences (SASHS) and the South African Society of Crop Production (SASCP). The congress and the journal are very student friendly and often the only platform where young soil scientists can present their ideas and get feedback

8. SSSSA is an association that must have had a good share of good and bad moments. What were the most significant challenges and proudest moments for 2022?

This year we had the Combined Congress online due to Covid regulations. The Combined Congress is a great place to network, meet up with soil scientists and other agricultural scientists from other institutions and parts of the country, share ideas and brainstorm about new projects or collaborations. The online congress, however, was a very different experience, and IT challenges were plenty. However, the society managed to organize webinars, host a photo competition on beautiful African soils, and successfully met all our targets for the year. 

9. What advice would you give another association with ambitions to influence and grow their industry?

Invest in your members, especially the younger ones, who will be your organisation’s future.

10. What could we expect from SSSSA for 2023?

The SSSSA is celebrating our 70th ‘birthday’, so 2023 is a special year. We kick off with the Combined Congress. We also have a photo competition each year, which is a very exciting and fun way to get members involved throughout the year (pictures of beautiful African soils can be seen on our website, www.soils.org.za). We will also host several webinars and attend the international soil science conference.