Our rehabilitation specialists at Kriel Colliery continue to raise the bar in demonstrating what can be achieved on carefully rehabilitated land disturbed by opencast mining.
One of the so called ‘glass ceilings’ currently being challenged is the generation of cash crops on previously mined land, which many believe is at best marginal and at worst impossible.
Kriel Colliery has contributed to a growing body of knowledge that is disproving this perception.
Rehabilitation superintendent Wilhelm Van Zyl set about investigating the possibility of raising cash crops on large stretches of rehabilitated property in 2014, and the initial results are promising to say the least.
Trials began with the establishment of maize on 400ha of rehabilitated land. Following a successful harvest, soya beans were planted with yields being sold through regular market channels. Wilhelm Van Zyl reports that harvests on the mine’s old block 6 operation yielded one ton of produce per hectare in comparison with an output of double that on an existing arable control strip.
“These results are extremely encouraging. They not only prove that it is possible for mine land to deliver cash crops of an acceptable standard, but that with a little more effort there is huge potential for yields to be further improved,” says environmental land manager Jurie Human.
The next step will be to assess potential nutrient deficiencies, which can be addressed, and to determine whether yields were impacted by drought conditions during last year’s growing season.
Willem Van Zyl explains the rationale behind the selection of soya as a trial crop. “Soya beans present a variety of benefits to farmers, industry, food processors, and consumers. They also improve the nitrate concentration in soil, which saves on the use of fertilizers in the next stage of the rotation cycle.”
He adds that crop rotation increases yields by improving soil conditions and reducing weed and insect populations.
“Overall, public perception of mining is negative, with one of the reasons being its impact on land that could be used for food production. Learning from trials like this one, our business is working towards ensuring that no net loss in land capability occurs,” says Jurie Human.