The Sunday News
Hazel Marimbiza, Features Correspondent
THE impact of illegal gold mining activities on agriculture in villages surrounding Zvishavane has been massive.
During productive years villages of Mhondongori and Mapirimira used to grow lots of maize, wheat, groundnuts, sugar cane, sugar beans, and mango and guava trees which they used to trade and cover a lot of economic gaps.
Their rivers used to be alive with fish, hippopotamus and crocodiles. Wetlands used to be decorated by different kinds of chirping birds — the kurrichane thrush, crested barbet, paradise flycatcher, tropical boubou, white browed ribin, black coucal, cardinal woodpecker and the long-crested eagle. Green snakes, frogs, grasshoppers, aquatic invertebrates, tadpoles and tortoises could also be found in the wetlands which were also rich in nutrients.
But with time, villagers began to notice problems caused by gold miners on the environment specifically on their farms.
“Our produce was affected, our land was getting degraded. Siltation was a major problem. The dumps were washed into our fields. Now our produce has literally been halved,” said Mr Silibaziso Dube, who has been fighting for restoration of degraded land.
Mr Dube and other farmers from Mhondongori told Sunday News that the accumulation of silt in water bodies and fields which was a result of mining activities was the central cause of problems in agricultural production.
Mr Misheck Ndlovu, an agriculturalist in the area explained that during the mining excavation process, two types of materials wash into the fields.
“One is the overload, the top soil that is removed when digging for the ore. The second type is the rejected material (the overburden) that forms massive hillocks over time and gets washed away into the fields as silt during the rainy season. The rejects have a high amount of calcium, which prevents the soil from absorbing iron, and you end up with crops yellowing and browning.
“Then there is the waste produced by the beneficiation process, which is a process of optimising the ore to make it a higher quality substance. Once the ore is extracted from the mine, trucks carry it to the beneficiation (or screening) plant. The process produces silica and limestone tailings. Silica is like fine dust particles, and fills up all the porous spaces, not allowing water to seep through the soil. It does not allow water to go up the plant via capillary action either,” explained Mr Ndlovu.
He further highlighted that limestone tailings are often materials of very fine grain size but size can differ depending on the parent rock, and range in diameter.
“Limestone tailings cover the soil and prevent absorption of nutrients. Fine particle sizes often lead to compaction, low infiltration rates, and high bulk,” he said.
Furthermore, research indicates that the tailings lack organic matter and are often acidic and toxic due to high concentrations of heavy metals, such as arsenic, cadmium, copper, manganese, lead, and zinc. In the absence of proper structures that can stem the movement of silt, the harmful waste gets washed by rain into the drainage network, entering the fields and choking them.
In January 2020, soil testing was conducted in Mr Dube’s fields. The results showed the soil to be strongly acidic.
“They suggested that we use double the amount fertiliser, but no matter how much we use, the output is barely 40 percent. Our fields are completely choked with silt. Look at this soil. The field soil is supposed to be clayey and black.
This is red, useless silt from the mines. Our crops are dying because of this,” said the 53-year-old Mr Dube as he showed his fists full of red earth and questioned, “How are we going to grow anything?”
According to research the rainy season is the worst for the silted fields. Under normal circumstances, fields are flooded in the early part of the rainy season, which is when the seeds germinate. After some time, the fields are drained by channelling water back into rivers or streams. But here, heavy silting of the river and stream beds reduces their water-holding capacity, causing an overflow. The water in the fields cannot be channelled back into the drainage network, leaving the fields waterlogged for long periods of time. The germinated seeds begin to rot and eventually die.
A 2014 study in the areas indicates that the number of cultivators and agricultural workers in Mhondongori and Mapirimira have declined over the years.
“It’s because of diversion of agricultural land for mining, and siltation, which renders the fields useless. Out of the 151 farmers interviewed in the study, 71 percent complained of a reduction in yields, attributing it to siltation and inadequate irrigation,” indicated the study.
“The worst part is, it is the duty of the mining companies and government to stop this illegal mining and restore the land. But they are not doing anything for us,” said Mrs Lubelihle Sibanda, a farmer based in Mapirimira.
The miners seem to have washed their hands off the matter.
A small-scale miner who spoke on condition of anonymity said: “We have no jobs but we have families to feed so we are not going to leave this place, we will continue digging for the gold.”
What next for mining and farmers?
In a statement the Environmental Management Agency (Ema) said illegal gold panners were destroying the environment and causing land degradation through illegal mining activities.
“These illegal gold panners are a menace to the environment, which we are trying to protect as Ema. We are therefore saying even miners operating legally should be regulated to protect the environment,” said Ema.
In response to a rise in illegal mining along riverbeds all over the country, Information Minister Monica Mutsvangwa said in a cabinet press briefing last year in September that, apart from a few exceptions, “all riverbed alluvial and riverbed mining on rivers is banned with immediate effect.”
Deputy Minister of Mines and Mining Development Mr Polite Kambamura said that small-scale miners should register their mining activities to ensure they follow proper mining standards and do not harm the environment.
“It is a punishable offence for one to mine without registration. Besides poor mineral accountability and environmental damage, proper mining standards are not being followed in these areas,” he said.
The Government has for the past few years been trying to register all small-scale artisanal miners. Researchers say the government should give artisanal mining cooperatives legal standing, pay gold producers at world prices and resolve the mining and environment dispute.
Experts indicate that mining companies should co-operate with artisanal miners, whose representative bodies should professionalise and multilateral organisations are encouraged to include metrics on mining when assessing Zimbabwe’s reform.
The Zimbabwe Environmental Law Association (Zela) in a statement said environment management must be encouraged at all costs and illegal mining should be shunned.
“This is because the destruction of these rich in biodiversity but fragile ecosystems has a high cost not only for the present but future generations as well. The disruption of our wetlands and farming areas by miners must cease, while the remaining ones must be retained, and where possible rehabilitation, restoration and re-creation of the environment must be attempted,” said Zela.
Funds are therefore required for restoring the ecology damaged by mining activities. The funds should be channelled to desilting of water bodies including dams and rivers, installation of pollution control devices, sewage treatment plants, afforestation, and any other measures for enhancing environmental quality in mining districts.
