Why Kenyan farmers must rethink reliance on chemicals

Kenya’s farms feed the nation and earn vital foreign exchange, yet the chemicals propping up much of that production exact a quiet, accumulating toll.

Highly hazardous pesticides and herbicides, many already banned in Europe, blanket fields of maize, coffee, vegetables and flowers. Their impact extends far beyond the target pests and weeds.

Non-target organisms pay the highest price, specifically, bees and other pollinators collapse under broad-spectrum insecticides; beneficial predators and parasitoids, mostly tiny wasps and flies, whose immature stages develop on or inside a single host pest, ultimately killing thus keeping pest populations in check begin to disappear; soil microbes essential for fertility are disrupted; aquatic life suffers from runoff; and residues enter the food chain, with documented risks to human health ranging from acute poisoning to chronic conditions.

Paraquat, as flagged in the African Uncensored documentary available online, and similar herbicides illustrate the problem starkly. Extremely toxic on contact, they kill indiscriminately and leave little room for recovery among non-target plants and the insects that depend on them. Insecticides containing substances such as imidacloprid (synthetic insecticide) or chlorpyrifos (nerve-agent pesticide) further erode biodiversity.

When 76 per cent of the pesticide volume used in Kenya consists of highly hazardous products, and nearly half of that volume involves substances already rejected elsewhere, the scale of collateral damage becomes impossible to ignore. Farmers, farmworkers and rural communities absorb the most immediate exposure, while the longer-term erosion of ecosystem services, pollination, natural pest control and soil health undermines the very productivity the chemicals were meant to protect.

Natural alternatives offer a more selective and environmentally compatible path. Botanical insecticides derived from pyrethrum, a crop Kenya once dominated globally, provide rapid knockdown of many insects while breaking down quickly in sunlight, leaving far lower residues. Neem extracts, microbial agents such as Bacillus thuringiensis, a natural soil-dwelling bacterium, fungal bioherbicides targeting parasitic weeds, and cultural methods.

Further, push-pull intercropping, crop rotation, mulching, and conservation of natural enemies reduce pressure on non-target organisms. These approaches support biodiversity rather than systematically eliminating it.

Reviving pyrethrum production, already showing modest recovery through better payments, seedling distribution and private investment, could simultaneously generate rural incomes and supply safer pest-control products. Home-made or locally formulated botanicals further lower costs for smallholders. Yet, honesty requires acknowledging the gaps. Natural products often have shorter residual activity, requiring more frequent application. Their efficacy can vary with weather, pest pressure and formulation quality.

Large-scale, labour-scarce weed control remains challenging; no single botanical fully matches the speed and spectrum of certain synthetic herbicides under all conditions. Commercial synthetics still fill critical roles where precision and reliability are essential, provided they are the least-hazardous options available, used only when necessary, and subject to rigorous oversight.

The solution is not an abrupt rejection of all chemistry but a decisive shift in priorities and rules. Kenya should accelerate the phase-out of substances banned in major jurisdictions of origin, enforce strict registration standards that prioritise environmental and human safety, require certified applicators and protective equipment for higher-risk products, and invest heavily in independent extension services that promote integrated pest management.

Labelling must be clear and in accessible languages. Residue monitoring and occupational health surveillance need strengthening. Meanwhile, public support for biopesticide research, pyrethrum value-chain development, and agroecological practices should expand so that safer tools become competitive and widely available.

Non-target organisms are not optional extras in agricultural systems; they are the foundation of resilience. Continuing to treat them as acceptable collateral damage is short-sighted.

Natural alternatives demonstrate that effective production need not come at such high ecological cost, while carefully regulated synthetics can address remaining gaps without repeating the mistakes of the past. Kenya has the knowledge, the crops and the policy tools to choose a more balanced path. The question is whether it will act before further irreversible losses accumulate.