Agrobiodiversity secures ecosystem and human health

Background

Climate change is exacerbating the vagaries of agricultural production, and nowhere is this more threatening than in sub-Saharan Africa. Rainfed subsistence farmers working increasingly degraded soils will continue to struggle to adapt to unreliable climatic conditions. Genetic diversity is vital to maintaining productive farming landscapes, as improved crop cultivars draw on the gene pool of crop wild relatives. However, the historically narrow focus of the seed industry on highly productive monocultures developed through centralized breeding has often proved inadequate for the wide range of farming conditions that smallholders in Africa are exposed to.

Innovation

Helping farmers to cope with climate change may depend on improving the agrobiodiversity of their fields, which includes both harvested and non-harvested species. WLE-supported research on agroecological approaches that incorporate biodiversity into agricultural systems – by allowing semi-natural and natural ecosystems such as grassed waterways, riparian buffers, prairie strips and hedgerows to flourish within, around and between farms – suggests that this can be achieved without compromising farmers’ ability to provide food for the growing global population. Indeed, the ecosystem functions provided by biodiversity are critical to food production and the planet’s hydrological and climatic stability.

Diversity within cultivated crops is part of an agroecological approach, and mixed seed systems reduce the production uncertainty associated with monocultures. Programs such as Seeds for Needs emphasize the importance of viewing seed systems as farmer-driven combinations of formal (improved varieties) and informal (landraces) selections that work better for them in local conditions. However, smallholders often lack the resources and information needed to access a diversified set of better-performing varieties. Furthermore, smallholder farmers are usually excluded from scientific debates and the design of research and innovation programs. Initiatives to bridge this gap include participatory multilocation trials and crowdsourced citizen science to gather information on the most suitable varieties under marginal conditions. Integrating centralized and decentralized approaches would not only enable farmers to make better-informed decisions, it would also build social cohesion through farmer exchange of knowledge and seeds, in turn encouraging the adoption and dissemination of new varieties.

Researchers have also developed metrics to better understand how seeds contribute to crop diversity and food systems, including:

• Seed access for formal, intermediate and informal seed systems.
• Seed production and distribution.
• Innovation, including the investments made and the institutions involved.
• Regulation that ensures appropriate seeds are released, including the right of farmers to exchange and sell seeds.

Impact

Through programs such as Seeds for Needs, farmers have been able to access crop varieties that are potentially suited to their agroecological contexts by offering their fields for experimental trials. Community seedbanks have been set up that enhance the availability of high-quality seeds of preferred varieties. In Ethiopia, hundreds of durum wheat landraces and several improved lines underwent extensive participatory analysis, which showed that landraces represent an important and mostly unexplored source of durum wheat diversity: 20% performed better than commercial varieties. Consequently, the Ethiopian government approved two new wheat varieties for distribution. These findings have been confirmed in Uganda, where a risk-minimizing strategy for traditional crop variety use is supported by superior resistance to pests and disease. In Nepal, six varieties of traditional but underutilized crops were officially registered, paving the way for farmers to benefit from legal and commercial seed production of these landraces.

Challenges

It is increasingly clear that diversified seed systems and biodiversity are critical to agricultural, ecosystem and human health. But the linkages between seed systems and agrobiodiversity – and thus sustainable food production and healthy diets – have not been explored sufficiently. Monitoring of seed systems is often limited to the formal sector, and agricultural innovation investments draw largely from the datasets this sector generates. The lack of wide-scale monitoring to include more informal seed systems and their differential impacts on household risks is reinforcing the current policy fragmentation around sustainable food systems.

Next steps

Governments remain heavily invested in supporting seed systems that focus on productivity. Public policies that explicitly seek to improve agrobiodiversity through seed systems and land restoration will increase the overall resilience of the sector in a changing climate. Using the metrics that have been developed, more datasets should be established to assess and guide policies and investments objectively and inform decision-making at the national level. Finally, but crucially, it will be important to generate value chains specifically for traditional varieties and neglected species, so that these resources not only contribute to resilience and food/nutrition security, but also to livelihoods.