South African agriculture stands at a crossroads, grappling with soil degradation, climate variability, and the heavy reliance on chemical fertilisers that threaten long-term productivity. A groundbreaking study from Tshwane University of Technology (TUT) sheds light on a critical barrier: why smallholder farmers are slow to adopt sustainable alternatives like biological fertilisers. Led by researcher Mokgadi Miranda Hlongwane, this work highlights the university's pivotal role in advancing eco-friendly farming solutions tailored to local needs.

The Imperative for Sustainable Fertilisers in South African Farming

South Africa's agricultural sector, vital to food security and the economy, faces mounting pressure from depleted soils and erratic weather patterns. Chemical fertilisers, while boosting short-term yields, contribute to soil acidification, nutrient imbalances, and pollution through runoff causing eutrophication in water bodies. Sustainable alternatives, particularly biological ones harnessing microbes like rhizobia bacteria, offer a path forward by fixing atmospheric nitrogen naturally, enhancing soil microbial diversity, and improving resilience to drought.

Rhizobia (Rhizobium and Bradyrhizobium species) form symbiotic relationships with legume roots, converting inert nitrogen gas (N2) into ammonia usable by plants. This process, known as biological nitrogen fixation (BNF), reduces dependency on synthetic inputs, cuts costs, and promotes healthier ecosystems. TUT's research underscores how these biofertilisers not only sustain legume crops like soybeans, common beans, and bambara groundnuts but also benefit subsequent non-legume crops through residue incorporation or rotation.

TUT's Landmark PhD Research: Unpacking Farmer Resistance

Mokgadi Hlongwane's doctoral investigation at TUT delved into rhizobia's efficacy on indigenous plants like Sutherlandia frutescens (cancer bush), a traditional remedy for inflammation and immune support. Her experiments demonstrated enhanced plant growth, nutrient uptake, and bioactive compound production under rhizobial inoculation, even in nutrient-poor soils. This TUT-hosted study positions the university as a leader in validating biofertilisers for both food and medicinal crops.

Fieldwork in Phiring village, Limpopo—a hub for smallholder farming—provided real-world insights. Interviews with 15 farmers revealed unanimous dependence on chemical fertilisers supplied free via the government's Comprehensive Agricultural Support Programme (CASP).CASP guidelines prioritise synthetic inputs, sidelining biological options despite their availability on commercial markets.

Key Barriers Identified: Access, Knowledge, and Policy Hurdles

Hlongwane's findings pinpoint multifaceted resistance rooted in systemic issues:

• Limited Availability: Biological fertilisers are not stocked locally; farmers must source from distant suppliers, unlike ubiquitous chemicals.
• Knowledge Gaps: Misconceptions abound—crops allegedly grow slowly, rot prematurely, or yield poorly. Peer advice trumps manufacturer instructions, leading to improper dosing without soil testing.
• Government Dependency: CASP's chemical focus creates inertia; free supplies disincentivise investment in alternatives.
• Economic Pressures: Smallholders lack funds for trials amid immediate yield needs.

These echo broader studies on climate-smart agriculture adoption in Limpopo, where similar constraints hinder innovation.

Photo by Markus Winkler on Unsplash

TUT's Ecosystem of Sustainable Agriculture Expertise

Underpinning Hlongwane's work is TUT's robust research portfolio. Prof. Felix Dapare Dakora, SARChI Chair in Rhizobial Biotechnology, has pioneered legume-rhizobia symbiosis studies, showing African soils' potential for BNF to cut fertiliser needs by up to 80kg N/ha.

Assoc. Prof. Grany Senyolo, in Agricultural Economics, champions tech-driven solutions like precision farming apps for fertiliser optimisation, aligning with TUT's innovation hubs fostering farmer-university partnerships.

TUT's Crop Science Department integrates these efforts, training students in biofertiliser production and extension services, bridging academia and fields.

Stakeholder Perspectives: Farmers, Policymakers, and Industry

Farmers in Phiring voiced eagerness for change but frustration over logistics. One noted, "Our soil is tired from chemicals; yields drop yearly, but where do we get the biological stuff?" Policymakers via Department of Agriculture must reform CASP to subsidise bio-inputs, as recommended in Hlongwane's analysis.

Industry players like rhizobia producers eye scale-up, but need extension agents—roles universities like TUT can fill through agribusiness programmes. Multi-perspective views emphasise collaborative demos proving biofertiliser ROI.

Environmental and Economic Implications

Persistent chemical use exacerbates SA's eutrophication crises in Vaal and Limpopo rivers. Biofertilisers mitigate this, boosting soil organic matter by 20-30% over seasons, per related TUT trials. Economically, smallholders could save R5,000/ha annually while lifting yields 15-25% via healthier soils.

Climate projections warn of intensified droughts; rhizobia's stress tolerance aligns with SA's National Climate Change Adaptation Strategy.

Solutions and Actionable Insights from TUT Research

• Conduct soil tests via university labs to match biofertilisers to needs.
• Farmer field schools hosted by TUT for hands-on training.
• Policy advocacy for CASP diversification.
• Incentivise intercropping legumes with maize for N carryover.

Hlongwane proposes demo plots in villages, leveraging TUT's proximity to Pretoria farmlands.

Photo by Karl Solano on Unsplash

Higher Education's Role in Transforming SA Agriculture

SA universities like TUT, UKZN, and UFS drive this shift. TUT's Vital repository hosts Hlongwane's thesis, open-access for extension workers.Access her full PhD here. Collaborations with ARC-DLR amplify impact, training 500+ extensionists yearly.

Through NRF-rated researchers like Dakora (A-rating), TUT exemplifies how higher ed fosters resilient food systems.

Future Outlook: Scaling TUT's Innovations

With COP commitments and AfCFTA, biofertiliser demand surges. TUT eyes commercial rhizobia strains for export. By 2030, widespread adoption could halve SA's fertiliser imports (R20bn/year), per economic models. Challenges remain, but TUT's evidence-based approach charts the way forward.

For farmers, unis offer free consultations; for students, ag econ programmes promise careers in green ag.