Harsh weather conditions are having an undesirable impact on South Africa’s soil health and experts anticipate soil degradation on a large scale. Sixolse Mcinga, soil scientist and senior analyst for sustainable agriculture at Green Cape, breaks down what is happening with South Africa’s farm soil and offers tips on how to best protect it, in both extremely dry and wet weather conditions.
Wet weather conditions, known as La Niña, have quickly turned to drier weather. Scientists now warn of the likelihood of El Niño kicking in later this year.
La Niña is a weather pattern that results in the abnormal cooling of sea surface temperatures in the Pacific, while El Niño spells below-normal rainfall and hotter temperatures for Mzansi.
What does this mean for agricultural conditions in the country, but more especially our soil, and what can farmers do? Mcinga answers these questions below.
Sinenhlanhla Ngwenya: South Africa is currently experiencing a lot of extreme weather conditions. How’s this changing our soil?
Sixolise Macinga: I remember I was literally having this conversation with a friend of mine and it depends on how you look at it. If you look at the recent heavy rainfalls that we have been experiencing, for some crops it was good, but the recent effects of it are that everything is just extreme. If it rains, there is too much rain and if it’s hot, there is too much heat.
There have been very extreme changes in weather conditions. Number one, climate change is real. It even pushed the planting season to very late in 2022 alone because people experienced so much rain that they could not even start their planting. So, there has been a ripple effect in terms of quality produce.
If you look at it from the soil’s perspective, with all the rains that we’ve had, there has been leeching of nutrients that you would find in soils. This means that there is going to be much more soil degradation. The rate that this has been happening is very intense.
In terms of production, farmers must really hold hands because they will be going through a rough patch. Last year alone, we couldn’t produce enough vegetables to put on the market, so this means that this is really affecting agricultural production. What this does is that it pushes agricultural production to a more controlled environment which a lot of farmers cannot tap into because it requires capital injection. It is expensive!
School us a little. What really happens when the soil is too wet or too dry?
When it comes to crop production, if the soil is too wet, it means that there is no air flowing into it. If there is no air flowing in the soil properly itself, it basically means that plants are like human beings and they need oxygen just like we do. It means that it has taken the pause that is supposed to be your oxygen. What happens is that it creates anaerobic conditions, and if this happens, it means that your crops will not survive, no matter how much water is there. Normal crops like maize, cabbage, and spinach, will not survive under those conditions.
This means that you will start noticing a greyer soil which disturbs the chemical makeup of the soil itself.
If we talk about extreme drought, roots are little hairs that need to be able to navigate their way down and outsource nutrients and water. So, everything will need that water; and imagine a situation where you are trying to reach out for water and it is way too far, you cannot get it.
No matter how hard you try, you’ll die. If there is too much heat, the crops are not able to take up any nutrients and they try to survive by themselves and there is death. This is the same with us, if you have stuck in the desert with too much heat and no water, you as a human being will die.
How best can farmers retain nutrients during extreme weather conditions?
If you are going to rely on natural conditions for agricultural conditions, the best way to go is to use regenerative agricultural practices.
For example, one of the regenerative agricultural methods that we can use for primary crops like maize would be conservative agriculture. Instead of taking the harvest away and clearing your field, you keep some of the residues on the ground and it will retain some moisture.
When it’s extremely hot, the sun’s rays do not hit the soil directly, because of the protective shield you have provided for the soil. It then creates a nice micro-climate for the good kind of micro-organisms to dry and this facilitates the availability of water and all the micro-organisms that we need for crop production.
One of the practices is residue retention and the other one is minimum tillage. This is when you don’t have to turn your soil over completely like what the big tractors do.
You can just open the area of the soil that you’re going to use and use your hand to open the soil, and then place the crop in it. A lot of farmers complain that it’s not practical on a larger scale, but the reality is that it works. The good thing is that there are implements that have been designed to help assist with this kind of method.
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What lessons have you learned so far in terms of soil research?
I have a very strong research background and a lot of it has been around looking at mechanisms that can improve our soil, and methods that can help protect our soil better as well.
It speaks to how we can use all these different mechanisms and incorporate them together in wanting to improve our soil quality. The biggest lesson is that firstly, all this information that has been in existence changes, not a lot though.
This is because a lot of these things have been experienced like climate change, and research pushes us to new knowledge that helps us find the solution. The biggest lesson I learnt was that research is something for you to change and you have to be flexible enough to understand that.
Practically, I think all this knowledge that we’re talking about, the scientific knowledge that we acquire in school all goes back to indigenous knowledge. Anyone who can incorporate all these things, research knowledge, knowledge from school, and indigenous knowledge really can go far with their agricultural production.
The saying, let’s get our hands dirty, how best do you relate to it?
Girl, if you could see me with the soil! I play with the soil. I used to work for the Agricultural Research Council (ARC), and we had five or six trials all over South Africa and we would go and get our hands dirty in the literal sense.
Initially, I used to say ‘oh no I want to work in the lab because I don’t want to get my hands dirty, I don’t want this life of a farmer’. But, when you tap into it you just see that, I mean I don’t want to say ‘spiritual’, but there really is something spiritual about getting your hands dirty. It is beautiful!
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