Invasive species threaten livelihoods of small-scale farmers

Daily Maverick

06-05-2025

Billions of rands in damage is inflicted on South Africa's economy every year — invasive alien species are the single biggest threat to the country's biodiversity.
Invasive alien plants (IAPs) pose a direct threat not only to South Africa's biological diversity, but also to water security, food security, the ecological functioning of natural systems and the productive use of land.
Joseph Mbatha is a small-scale farmer from kwaNongoma in Northern KwaZulu-Natal who has lost goats and viable planting land due to an invasive species, parthenium. The plant has taken over the vegetation in the area.
'The worst thing about this plant is it replaces grass and nothing grows next to it. We tried to cut it, but its seeds lay there and came up the next time there was rain. Goats feed on it and become very sick; they get diarrhoea and die,' said Mbatha.
Nhlanhla Mthembu, project manager at HPSA, formerly known as Heifer International South Africa, said farmers had been raising concerns over the spread of parthenium. HPSA has linked the plant to the livestock mortalities and a high rate of sickness.
HPSA is a nonprofit and a public benefit organisation that works with impoverished rural South African communities to end hunger and poverty by empowering them to develop skills in sustainable agriculture and commerce.
'It was important for the project team to carry out a short study to find out if there are any links to parthenium and livestock mortalities. This was carried out in five districts – Zululand, uMkhanyakude, King Cetshwayo, uMzinyathi and uThukela.
'The main objective of collecting data was to also find solutions regarding the exact causes of mortality and treatment interventions going forward. It was essential to collect … information from farmers to initiate discussions on what parthenium is, what its impacts are on livestock and humans and also discuss control methods, if any exist,' said Mthembu
The interviews discovered that 76.58% of farmers who said parthenium was a problem found coccidiosis/diarrhoea to be an issue.
A total of 373 farmers owning 5,939 goats were interviewed. Most farmers said they began to notice parthenium between 2012 and 2016. Although the findings note that the deaths are not exclusively from the weeds, of the 5,935 goats, 3,737 goats had died — 76% of these from coccidiosis/ diarrhoea.
A study released in 2024 looked at the impact of parthenium in South Africa, stating that parthenium hysterophorus, commonly known as famine weed, is highly invasive in South Africa; it causes significant ecological and economic impacts. 'It threatens food security, native biodiversity, livelihoods and human health, particularly in savanna regions. Parthenium outcompetes native grasses, reducing fodder for livestock,' the study finds.
Parthenium is progressively spreading across the country and covers vast areas of KwaZulu-Natal and Mpumalanga, as well as North West, Limpopo, and Gauteng, says the study.
Aaron Mlambo, a small-scale farmer in the area, said, 'Our goats are going hungry; this is an even bigger problem for pregnant goats and mothers because when they are hungry, they cannot feed their young; they kick the kids. I have lost so many young goats because of this.'
Interventions
KZN agriculture MEC Thembeni kaMadlopha-Mthethwa said: 'We have a land care programme where communities organise themselves and ask the department to help with an invasive plant species. What we do is send our officials to assess and clear the area with major involvement of community members. It ends up providing short-term employment where communities themselves are part of clearing the area.'
The land care programme has moved to the KZN Department of Economic Development under its environmental wing. However, small-scale farmers Daily Maverick spoke to were not aware of the programme.
Solutions
Mthembu said the HPSA was investigating how to get rid of the weed while it helped farmers treat the symptoms in livestock. Currently, farmers treat coccidiosis and diarrhoea with antibiotics and other medicines. This was not ideal as there could be antibiotic resistance. The treatments were expensive for lower-income farmers who often 'sell livestock to afford the medicine', said Mthembu.
'We have spoken to scientists on solutions to get rid of the invasive species and they suggested introducing a pest that can eat these plants. But communities are concerned because they don't know if these pests will eat their crops as well, so we are still looking for a viable solution that communities will also be comfortable with.'
Food security and climate change
The prevalence of invasive species has been attributed to climate change, which took centre stage at the G20 food security working group in Durban last week.
South African Minister of Agriculture John Steenhuisen, with KZN agriculture MEC KaMadlopha-Mthethwa, hosted world leaders to familiarise themselves with best practices and create platforms of collaboration to build resilience.
In response to a question on how his department was planning to help small-scale and commercial farmers with the impact of climate change, Steenhuisen said, 'KwaZulu-Natal is a primary example of the impact of climate change – there have been floods, fires, drought, and the province has experienced everything but the plague.'
He said there were multiple interventions targeted at building climate change resilience, which included biosecurity and enriching biodiversity.
'This is a tactical meeting; the outcome will be learning best practices from international bodies, such as the [UN Food and Agriculture Organization], that also provide project funding, so we want to see how we can have a general meeting of minds.
'I look forward to having further discussions on greater collaboration between countries. As you know, a lot of our small-scale farmers and commercial farmers struggle with input costs such as fertiliser and other costs that end up impacting the cost of food. We also discussed how to cooperate on technology; Ukraine, for example, uses a lot of precision agriculture technology, and we can learn how to increase yields.' Steenhuisen said.
'This is a moment of both urgency and opportunity. Urgency, because food insecurity, climate volatility and systemic exclusion continue to threaten the stability of global food systems.
'Opportunity, because never has the world had such scientific insight, technological capacity and a shared policy platform to do something about it,' said Steenhuisen. DM