Different incentives exist. The organic certification process of soil is very expensive (in terms of time, not cash), which creates a big incentive for organic farmers to protect it from erosion. Organic practices involve a lot more living matter being put into the soil that helps to retain water, a lot more mulching to protect it from erosion.
Conventional farmers, with access to cheaper fertilizers and the like, lack the extra incentive to protect their existing soil.
I expect as global warming shifts incentives (like the need for carbon-neutral fertilizers, drought-tolerant soil, etc) organic farming practices for soil management will get adopted by conventional farmers. Proving these techniques out will be how organic farmers are remembered, not the nonsense about GMOs.
Remember that anything an organic farmer can do a conventional farmer can do as well, and probably is.