The rehabilitation of the land at the test pit site mined during triple-listed Sovereign Metals’ pilot mining and land rehabilitation programme at its Kasiya rutile/graphite project, in Malawi, has been substantially progressed, the company said on March 5.

Soils remediation work was concluded in December last year, with landowners accessing the site between December and January to plant and cultivate crops without missing a planting season.

"The successful return of farmers to their land within such a short time and without missing a single planting season after mining and backfilling 170 000 m³ is an excellent outcome. This . . . will build on our positive community relationships.

“The pilot phase of 90 farmers selected for our conservation farming programme has been increased to 350 for this season. Early indications are that the second season of this programme will exceed the 300% yield increases achieved in the pilot phase.

“The empirical data collected from these trials will feed directly into our definitive feasibility study designs for mine closure and land rehabilitation," Sovereign MD and CEO Frank Eagar said.

The soil remediation works and planting were done by hand with the use of a grader and tractor to prepare the soils. Sovereign appointed local landowners to work alongside the company in both the soil remediation and planting work, allowing them to directly experience and learn about the rehabilitation work on their land.

Sovereign said it was working closely with the landowners to ensure the crops provided a good yield this year, while simultaneously testing a variety of rehabilitation crops. This includes the intercropping of giant bamboo with maize, which will be retained by the landowners.

Sovereign said all mined-out land would be rehabilitated to support sustainable farming practices after closure.

The soil remediation methods aim to revitalise the soils within a two- to three-year timeframe and to ensure that soils can be sustainably farmed in the long term. The remediation of soil to a depth of 1 m from surface should ensure the land can support small-scale or full commercial farming operations going forward.

As part of the pilot phase, the company built small rehabilitation demonstration pits that will be used to illustrate multiple and ongoing rehabilitation processes.

REHABILITATION APPROACH

The rehabilitation approach has been based on agronomic principles, including promoting sustainable farming practices and providing various land uses post mining activities.

Rehabilitation is under way through a five-step process.

The first step, to introduce lime, has been completed.

The soil remediation began with the application and incorporation of locally sourced dolomitic lime (calcium and calcium-magnesium carbonate) to improve naturally low pH levels.

The second and third steps – introducing carbon and basic nutrients and grading, ripping and discing – have also been completed.

Sovereign augmented the mined area with organic carbon and basic nutrients. Tests include the application of biochar to provide carbon and fertiliser in the form of potash, phosphate and a blend of nitrogen, potash and sulphur.

Lime, biochar, and fertiliser were incorporated into the soil through grading, ripping and discing using graders and locally sourced farming equipment. This ensured that the land was level along with safe working conditions. 

Steps four and five – the planting of rehabilitation crops and monitoring and evaluation – are in progress.

Since December, Sovereign has progressively been planting various rehabilitation crops to maximise the benefit of the coming summer rainfall.

Giant bamboo has been introduced in 4 m by 8 m blocks, which will act as the primary crop to enhance carbon and bio-activity in the remediated soils. Maize and other cover crops have been intercropped between the giant bamboo within reorganised farm blocks.

Sovereign is currently monitoring soil remediation, plant growth and crop yields. As part of stakeholder engagement, the company is working with local farmers to improve results through conservation farming, composting operations, testing new seed varieties and establishing an indigenous, fruit and farming nursery.

This is serving as a live demonstration of rehabilitation and timely return of land to a premining state.