Think of “farming” and those of us living in the more industrialised parts of the world usually envision large fields that are intensively worked using heavy machinery and regular inputs of fertilisers, pesticides and herbicides. But for 2 billion of the world’s farmers, agriculture takes place on smallholdings of less than 2 ha in size, with little money available for vehicles and chemicals. Maximising food outputs in such systems can be difficult.
Now a new study by Lucas Garibaldi, Luisa Carvalheiro and colleagues entitled “Mutually beneficial pollinator diversity and crop yield outcomes in small and large farms” has demonstrated that these small-scale farmers can increase the yields from insect pollinated crops on their farms by allowing native vegetation to grow alongside the crops, which supports a greater diversity and abundance of pollinators that then spill over into the adjacent fields.
It’s a great study that delivers a message that large agro-chemical firms probably will not wish to hear: that yields can be enhanced without throwing ever more fertiliser or pesticides onto the crops.
The paper is paywalled so you’ll have to ask the authors for a copy unless you (or your institution) has an e-subscription to Science. But here’s the original abstract:
Ecological intensification, or the improvement of crop yield through enhancement of biodiversity, may be a sustainable pathway toward greater food supplies. Such sustainable increases may be especially important for the 2 billion people reliant on small farms, many of which are undernourished, yet we know little about the efficacy of this approach. Using a coordinated protocol across regions and crops, we quantify to what degree enhancing pollinator density and richness can improve yields on 344 fields from 33 pollinator-dependent crop systems in small and large farms from Africa, Asia, and Latin America. For fields less than 2 hectares, we found that yield gaps could be closed by a median of 24% through higher flower-visitor density. For larger fields, such benefits only occurred at high flower-visitor richness. Worldwide, our study demonstrates that ecological intensification can create synchronous biodiversity and yield outcomes.
The challenge from this paper is two-fold. First of all it’s how to operationalise this kind of research on the ground, to farmers and agronomists who are unlikely to be readers of the journal Science. This is where organisations such as the UN’s FAO, country-level government agencies, and non-governmental organisations have a crucial role to play, translating research into action.
The second challenge is likewise difficult – how do we bring “ecological intensification” into the industrialised agriculture of more developed nations? I have no immediate answer to that, but research such as this shows what the potential benefits can be, for both agriculture and biodiversity.
The reference is: Garibaldi, L.A. et al. (2016) Mutually beneficial pollinator diversity and crop yield outcomes in small and large farms. Science 351: 388-391