Results & impact 14 October 2021
Agroecology in support of crop protection and the control of zoonoses
Some 300 references, 200 of which were produced within the last 10 years, provided the basis for the work of the two scientists from CIRAD, at the interface between agroecology and health. The findings are compelling: agroecological crop protection practices ultimately result in a reduction in the risks of viral zoonoses.
Crop health is central to controlling the emergence of viral zoonoses
Viral zoonoses, such as Covid-19, are at the interface between human, animal and ecosystem health. These diseases are transmitted either by arthropod vectors, such as mosquitoes, or by vertebrate reservoirs, crop pests, or pest predators.
“When we talk about zoonoses, we focus on human and animal health, and too often we overlook the importance of plant health, in particular that of cultivated plants”, says Alain Ratnadass, an entomologist at CIRAD and lead author of the article. “But many crop pests are virus carriers, such as rodents. This makes crop protection practices an important link in the chain of disease emergence.”
Agroecological crop protection builds on the principles of agroecology to redesign agroecosystems that are resilient to the pests and diseases of cultivated plants. Two focal areas structure this approach, on which CIRAD has been working for more than 15 years:
- Improving soil health
- Developing biodiversity in and around cultivated land
“Agroecological crop protection is based on the natural regulation of pests, fostering interactions between plant, animal and microbial communities”, says Jean-Philippe Deguine, also an entomologist at CIRAD and co-author of the article. “For example, to manage pests, we encourage biological control through conservation, by incorporating habitats that are favourable to the natural enemies of these pests. This approach enables crops to be grown with little or no pesticide use, and this is what we are striving to demonstrate in the fruit and vegetable cropping systems we are studying in Réunion.”
A lower risk of viral zoonoses
This review of scientific articles establishing the actual or potential impacts of different crop protection techniques on the emergence of viral zoonoses has helped to identify a clear trend: conventional crop protection practices, using pesticides and inputs, ultimately increase the risks of virus emergence, whereas agroecological crop protection reduces these risks.
“Applying the principles of agroecology to crop protection reduces the risks of viral zoonoses”, says Alain Ratnadass. “Our work also reveals that agroecological crop protection has positive impacts on biodiversity, resilience to climate change and animal welfare.”
Although this initial research focuses on viral zoonoses, the scientists suggest that similar findings could be obtained for bacterial and parasitic infectious diseases.
Alain Ratnadass and Jean-Philippe Deguine. 2021. Crop protection practices and viral zoonotic risks within a One Health framework. Science of the Total Environment 774: 145172.