Graham Bruce* discusses TAHA’s salt-free, energy-efficient, proprietary aluminium hot dross recovery process which eliminates toxic salt cake and produces a mineral-rich residue which TAHA labels Ouvea. These stabilised oxides form the base of Clover One— a fertiliser which is a blend of Ouvea, soil conditioners, and biological fertilisers.

TAHA Healthy Soils (THS), has tried to redefine industrial ecology by transforming the stabilised oxide residues from aluminium dross—long considered a waste by-product—into a valuable agricultural input.

Its flagship product, Clover One, represents a true circular-economy innovation: a fertiliser that boosts yields, builds soil health, and reduces negative environmental impact such as leaching.

Excess conventional fertiliser leaching into waterways releases excess nitrates and phosphates that fuel algal blooms, depleting oxygen, harming aquatic life, and posing serious risks to both ecosystems and water quality.

Measurable results

Independent field trials conducted in New Zealand farms (2011–2015) demonstrated that Ouvea-based fertilisers deliver equal or higher yields at half the nutrient application rate of conventional fertilisers. Results included up to 38% higher pasture yield, a 63% increase in active fungi, and 38% more active bacteria compared with urea-based controls.

In semi-arid trials, the crops of lucerne and cocksfoot maintained over 80% survival after four years, confirming long-term soil resilience.
Ouvea-based fertilisers have also proven effective in saline or salt-affected soils, particularly in the Middle East, where TAHA first established its operations and demonstrated that its mineral-rich formulations can buffer excess sodium, revitalise degraded land, and sustain crop growth where conventional fertilisers typically fail, or underperform.

Performance in the field

New Zealand is famous for its lamb. Farmers with lamb raised on pasture with biological fertilizers have been able to increase prices up to 30%, based on the product being recognised as a nutritious protein with superior mineral and food value qualities that the biological farming practice can establish in the meat.

Also in one particular case, the meat carcasses yielded up to 17% more meat than the industry average.

Clover One combines the productivity of a fertiliser with the restorative qualities of a soil conditioner.

Trials show up to 79% increases in pasture production compared to control, and cost efficiency as low as 11% of DAP cost (June 2015 benchmark). Clover One, certified for use in New Zealand and the European Union, improves clover content, enhances palatability for livestock, and delivers measurables on-farm profitability. As the soil becomes better conditioned and nutrient cycling improves, plants absorb more balanced minerals, livestock graze on healthier forage, and — as a welcome bonus — veterinary costs naturally decline. Lambing rates also increase.

Farmer testimonials

• “The pasture in the paddocks is 14 years old. Clover One has regenerated the area it was applied to but the other part needs it! Note the dark colour of the treated soil and the texture—the untreated is yellow/brown and hard to break apart, showing lack of biological activity.

• As a result of the biological system employed, stock health requirements are 30% less than the general farming industry.

• Lambing has also increased by 30%”—David Crutchley, Shortlands Station.

“We applied TAHA fertiliser products on barley, clover and lucerne paddocks . The barley crops that received the applications definitely yielded higher than our traditional fertiliser application. We have continued to apply TAHA products again this year.” —Lawlor Farm Partnership, Kelso.

Value

Clover One supports compliance with nutrient-management regulations by reducing nitrate leaching and soil acidification. It lowers lime demand by up to 25% and sustains yield at lower nutrient intensity. Economically, farmers achieve reduced input costs and greater livestock value.

Closing the loop
TAHA’s metallurgical innovation also reduces greenhouse gas emissions by 81% compared to rotary-salt processes.

With sustainability and zero waste as their main drivers, after the metal content has been returned to the customer, the company aims to convert every ton of dross into three value streams: steel slag conditioner, Ouvea-based fertilisers like Clover One, and aluminium trihydrate (ATH) for flame retardants, thus creating a closed-loop system downstream from dross that unites industry and agriculture under a single sustainability vision.

Bibliography & References
1. Espie, P. (2016). Taha Industries Fertiliser R&D Trials Report 2011–2015. AgScience Ltd., New Zealand.
2. TAHA AluSolutions Presentation. TAHA International Corporation, 2020.
3. Ouvea-based Product Information: B10 & Clover One. TAHA Healthy Soils, Technical Data Sheet, 2015.
4. Clover One Brochure (Rev. 3). TAHA Healthy Soils, 2016.
5. TAHA Sustainability and Fertiliser Overview. www.tahacorp.com, 2024.

*Director Global Business Development, Taha, Manama, Bahrain

For further information please see: www.tahacorp.com