Pollinator populations are declining globally, particularly in agricultural landscapes (Biesmeijer et al., 2006; Gill et al., 2016; Goulson, 2019; Goulson et al., 2015; Potts et al., 2010), largely due to multiple anthropogenic pressures such as land-use changes, agricultural intensification, monoculture, pollution (mainly by pesticides and fertilisers), pathogens, invasive species, and climate change (Gill et al., 2016; Potts et al., 2010; Sánchez-Bayo and Wyckhuys, 2019). An estimated 87% of flowering plants are dependent on pollinators, with this figure increasing to 94% in tropical communities (Ollerton et al., 2011). Consequently, declines to pollinator populations also impact the ecosystem services provided by these flowering plants and all those that depend on them, and can lead to interlinked degradation, cascades of extinctions, yield reduction, poverty spirals, and eventually “Pollinator Loss Syndrome” (Christmann, 2019; Dirzo et al., 2014).

Pollinator declines are particularly evident in agricultural landscapes, and yet 75% of food crops depend, at least partly, on animal pollination for fertilization (Klein et al., 2007). Pollination services for food production are thus vital for food production, with an estimated value of €153 billion in 2005 (Gallai et al., 2009), as well as for maintaining genetic diversity and resilience e.g. to climate change) (Christmann and Aw-Hassan, 2012), and yet agriculture itself can negatively impact the habitats and resources needed to sustain pollinators. In addition to the drivers above, agriculture and homogenous landscapes may also negatively impact pollinators through: 1) shorter flowering periods of homogenous crops that may be less than the time needed for pollinators to complete their life cycle; 2) monoculture crops that may not be suitable for specialist pollinators (those with narrow floral choices); and 3) pollinator independent crops (e.g. cereals such as wheat) which do not provide nectar or pollen for pollinators. Addressing drivers of pollinator decline and strengthening the protection and promotion of pollinator populations and pollinator diversity particularly in agricultural landscapes is therefore critical.

Farming with Alternative Pollinators (FAP) is an approach to both conserve and promote wild pollinators (i.e. ‘alternative’ pollinators to managed honeybees) in agroecosystems and to improve production and farmer incomes. By achieving social and ecological benefits through actions that sustainably manage and restore ecosystems while simultaneously addressing a societal challenge, it constitutes a nature-based solution (Cohen-Shacham et al., 2016). Developed by the International Center for Agriculture Research in the Dry Areas (ICARDA), FAP makes use of marketable habitat enhancement plants (MHEP) cultivated alongside the edges of farmer fields (Christmann and Aw-Hassan, 2012). The planting of MHEPs in FAP plots aims to improve pollinator habitats, thus increasing the diversity and abundance of wild pollinators, and consequently crop production both in terms of quantity and quality. The goal of this integrated agro-ecological socio-economic approach is that the resultant, visible increases in farmer income per surface area will motivate farmers to permanently adopt pollinator-friendly farming practices.

The FAP approach builds on evidence showing that native wild flowering plants are important for the conservation of pollinator populations in farmlands (Dicks et al., 2015; Nicholls and Altieri, 2013) and that sown wildflower strips also attract and provide habitat for wild pollinators, increasing the abundance and diversity of bumblebees (Carvell et al., 2007). Over the last two decades, wildflower strips along fields have been introduced in several European countries within the Agri-Environmental Schemes (AES) framework, with positive impacts to biodiversity and ecosystem services (Haaland et al., 2011). However, the high and continued implementation costs of these schemes have led to doubts over their broader accessibility (Batáry et al., 2015; Christmann, 2020; Uyttenbroeck et al., 2016), particularly for low and middle-income countries. The FAP approach uses MHEPs to provide similar resources to pollinators as wildflower strips, but with additional focus on benefits to farmer productivity and incomes, and improving farmer motivation (Christmann et al., 2022). Key elements in FAP approaches are crop diversification through a combination of pollinator-friendly main crop and MHEPs, temporally sequencing the planting of crops to achieve flowering overlap, habitat enhancement for pollinators by reducing harmful practices (e.g. pesticides, insecticides) and conservation agriculture practices.

ICARDA trials in Morocco and Uzbekistan have demonstrated a visibly higher yield and higher income of FAP fields compared with control plots, alongside higher pollinator abundance and diversity in FAP plots (Bencharki et al., 2023; Sentil et al., 2022a, 2022b). The visible socioeconomic benefits through FAP consequently motivated farmers to adopt the approach and conserve pollinators. Inspired by this research, Action against Hunger (ACF; an international aid NGO with the mandate to fight against hunger and its causes) initiated a FAP research project in Zimbabwe to validate the approach in a small-holder context in sub-Saharan Africa.

The agricultural production system in Zimbabwe is dominated by the high use of agrochemicals (herbicides, fungicides and insecticides, unsustainable monoculture cropping), tree cutting for firewood and tobacco curing, and agricultural expansion, requiring clearing of land (e.g. deforestation, bushfires) (Mudimu et al., 2015; Zimba and Zimudzi, 2016). These practices all have a negative impact on the wild pollinators which provide the majority of pollination services (Chakuya et al., 2022). This threatens biodiversity and adversely affects already resource-poor smallholder farmers who rely on ecosystem services such as pollination for their agricultural production, food and nutrition security and economic livelihoods. Therefore, to address the negative impacts of the practices of conventional farming on biodiversity and particularly on pollinator loss, there is a need to develop and promote alternative and sustainable solutions to conventional farming practices. The FAP method was selected (in conjunction with the use of other agroecology and sustainable agriculture techniques) for its holistic approach to farming which includes both socioeconomic and ecological benefits, and because the method itself was deemed in conjunction with local farming techniques.

This paper presents the results of FAP trials in two districts in Zimbabwe, Gokwe North and Gokwe South. The objective was to test the replicability and impact of the FAP approach in Zimbabwe. We hypothesised that using the FAP method to improve pollinator habitat would have a positive impact on pollinator abundance and diversity, and consequently have tangible benefits on crop yield (quantity and quality) and income of smallholder farmers in Zimbabwe. This research effort aims to produce scientific evidence to contribute to the existing FAP knowledge base as generated from other contexts. To our knowledge it is the first such study from sub-Saharan Africa.

In this study, we tested whether incorporating pollinator habitat enhancement practices in smallholder agriculture plots in Zimbabwe would significantly increase pollinator diversity and have impacts on crop yields and income. Our results are encouraging, with significantly higher counts and diversity of pollinators seen in FAP plots compared to control plots. FAP plots also had significantly higher value yields, and there was a significant correlation of pollinator abundance with yields and with total income. No single pollinator group seemed to be driving the differences observed between control and FAP plots; rather, all groups observed increased in abundance in FAP plots. It is worth noting that some pollinator groups were fairly general (e.g. butterflies), and it is possible that species diversity within these groups increased with pollinator abundance (e.g. some individual species that were not present in control plots were present in FAP plots) but this level of detail was not recorded to make monitoring accessible for field teams and to avoid taxonomic misidentification. We also did not specifically record natural enemies to crop pests, as has been done in some previous studies (Christmann et al., 2021a), the reduction in crop pests being another mechanism by which FAP may improve crop yields.

Although we did not measure pollinator abundance exclusively on the main crop but rather across the entire field, we found no significant increase in main crop yield or income in FAP plots. This indirectly suggests that FAP did not influence the abundance or richness of wild pollinators visiting the main crop or that crop production was not limited by pollinator abundance in control plots. However, our results were very close to statistical significance, aligning with previous contrasting findings on main crop yields, productivity, and pollinator abundance (e.g., increased productivity in Christmann et al., 2017; Christmann et al., 2021a; neutral effects in Zamorano et al., 2020; Sentil et al., 2024). Alternate explanations for a lack of effect of MHEP on main crops include the possibility that MHEP concentrate wild pollinator populations (Lander et al., 2011; Nicholson et al., 2019) or that time may be required for pollinators to establish around local crops (Albrecht et al., 2020).

In cycle 2, over half of income from FAP plots was from the 25% zones (MHEPs), with only moderate increases in the 75% zones (main crop) compared to control plots, suggesting that in this instance MHEPs act as a buffer against main crop income losses. Previous studies have reported income increases due to both main crop production and/or MHEP income. For example, Christmann et al. (2021a) reports that while most trials net-income increases are mainly due to increases in main crop production, during one pumpkin trial, MHEPs contributed 39% of income in a mountainous area. It may be that, in this trial, erratic crop production both between plots and potentially between years means that a buffer income source is particularly beneficial. The same study also reports only moderate benefits to okra production from increased pollinators, compared to “essential” impact of FAP for zucchini, pumpkin and melon (and “little” impact to tomatoes). Given varying impact of pollinators on crop production between crops, we might also expect different benefits of FAP to income profiles depending on the crop as well as on the risk of crop failure. To clarify this further, future research should aim to identify main crop pollinators, extend temporal coverage, and increase sampling effort.

The higher pollinator diversity and abundance in FAP plots gives an encouraging sign that FAP plots are beneficial to biodiversity as well as to the ecosystem services that those pollinators provide. Additionally, although impacts on non-pollinator diversity were not measured, anecdotal reports of benefits to fruit trees surrounding FAP fields were recorded.

The differences in pollinator abundance between Gokwe South and Gokwe North districts seen in cycle 3 may be explained by regional differences in water availability. Despite efforts to select plots with similar biogeochemical environmental conditions, future research will need to ensure additional environmental variables are recorded to ensure comparability between plots. Nevertheless, the diversity of environmental characteristics across the experimental plots, both in our work and in previous studies – including variation in soil physicochemical and biological properties (e.g. texture, pH, organic matter, microbial composition), meteorological and topographical features, as well as socioeconomic contexts – suggests that the FAP approach can be successfully applied across a wide range of landscapes and regions.

The results of our research corroborate the findings of previous FAP research conducted by ICARDA showing that plots containing MHEPs had higher wild pollinator abundance and diversity, and higher yield and income using main crops across plots as biologically and geographically varied as faba beans, eggplant, pumpkin, zucchini, tomato, apple and melon in Morrocco (Sentil et al., 2022b; Bencharki et al., 2023; Sentil et al., 2024) or sour chery and cucumber in Uzbekistan (Christmann et al., 2017). Importantly, our study demonstrates the potential of this agricultural method in a new context (i.e. sub-Saharan Africa) which is ecologically and socioeconomically distinct from previous FAP study regions, and represents an important further step towards validating this method as well as contributing more generally to the knowledge gap on pollinator biodiversity and on sustainable agriculture practices in this region. Indeed, estimating the contribution of pollinators to sustainable agriculture in sub-Saharan Africa has been constrained by limited data on pollinator species diversity and distribution and insufficient understanding of pollination gaps of pollinator-dependent crops (Tolera and Ballantyne, 2021).As with many pilot studies, there are some points to improve on for future projects. Most significant of these will be ensuring that all farmers follow the plot design and farming techniques: lack of adherence to plot standard design and common harmonised farming practices by community groups resulted in almost half of the experimental plots being excluded from the data analysis. The communal plots’ failure can be explained by a tragedy of the commons mechanism, where shared access and diffuse responsibility lead to its poor management. According to teams on the ground, individual plots did follow protocols fairly consistently, but unfortunately the failure to record the details of this (i.e. irrigation schedules, fertiliser use, etc) means that this remains anecdotal. Future studies should record these details more fully.

The visible effects of pollinator-friendly farming in the scope of the FAP trials can serve as motivation for farmers to reduce harmful behaviours that lead to pollinator decline, and indeed participating farmers were very positive about the FAP trial ( Supplementary Methods 1 ). Such projects are not viable without farmer adhesion (Christmann et al., 2021b; Bencharki et al., 2023), and despite limited prior awareness of pollinator benefits, farmer adoption was rapid and enthusiastic, driven by the clear and quickly observable increases in crop yields and net income associated with the FAP methodology, consistent with previous findings that the method is inherently incentivizing (Christmann et al., 2021b). Our choice to use a broader taxonomic resolution allows studies to be conducted across regions without extensive specialist training; though some species-level detail is lost, key outcomes such as farmer adoption and biodiversity recovery were achieved, and the approach remains easily replicable. Building on the encouraging first results, stakeholder adherence was strengthened through “model” farmers that trained others, through word-of-mouth, and by integrating the protocols into local agricultural extension services via live training, ensuring regular follow-up and monitoring by project staff, and addressing the financial requirements needed to scale up the approach.

This research has contributed to the on-going development of new agricultural training by local authorities and to Zimbabwe’s new national agroecology policy while aligning with their existing National Biodiversity Strategy and Action Plan (NBSAP). It also supports international conventions and frameworks on biodiversity, particularly as relating to agroecological principles and agro-biodiversity, diversification of income, and input reduction. However, for FAP to have the necessary space to scale up, it needs to be promoted through advocacy based on evidence that emphasize its value and potential in enhancing pollinators and increasing small-holder farmers’ yield and income. The FAP advocacy perspective aims to influence public policy decision-makers and donors, so FAP and other nature-based solutions are put back at the heart of national agricultural strategy and policies.