Microbiome mediated climate change resilience in organic farming systems

Farmers are grappling with the impacts of climate change globally, including increased extreme weather events and pest and pathogen outbreaks. While organic farms are predicted to be more climate change resilient than conventional counterparts, the mechanisms of this resilience are poorly understood. Plant genotype can play an important role in determining microbiome structure, function, and climate change resilience in natural ecosystems. However, evidence of microbiome-mediated climate change resilience from agroecosystems is scarce. Here we used reciprocal cross experiments to evaluate the impact of plant-microbiome interactions on farming system resilience to abiotic (drought) and biotic (aphid) stress. We grew crops from seven different organic seed producers in their natal (extracted from the farm where they were produced) and foreign (extracted from other organic farms) microbiomes. We then fit our data to a Crop × Environment × Microbiome model and hypothesized that plants would have increased fitness in their natal microbiome. Our findings will highlight if organic crops are adapting to their natal microbiome increasing insect pest suppression. We will also discuss whether foreign microbiomes can promote resilience to drought and pests. Our experiment effectively emulates organic vegetable systems, where seed crops grown in a natal microbiome for off-site sale are introduced to the foreign microbiomes of production farms annually. Taken together, our findings will indicate new approaches to match crops with microbial communities and environmental conditions across space as a mechanism for promoting organic and conventional farming system resilience to climate change and pest pressures in the future.