Studies show that basically the longer a farm is in organic production, the higher the yields are. A study that recently came out showed that we've lost 133 billion tonnes of carbon from our soils worldwide over the last 1,200 years due to agricultural production, so a lot of farmers are starting on soils that have already been incredibly degraded due to poor agricultural practices.
I think that to say that we can't increase yields without synthetic fertilizers is false. I think there is a role for synthetic fertilizers to play, generally, in agriculture, but I think there are a lot of practices we can use over time that are going to build the health of the soil, build that organic matter, and build that nutrient base so that we do see over time that yields are rising. But we need to invest in getting there first. If you take degraded soils and you stop using fertilizers, you're not going to have a good yield.