"There is resistance among farmers not only because the seeds are expensive, but also because the species used so far, especially Stylosanthes, do not persist when associated with Brachiaria grasses", Boddey explains. After some time in the field the leguminous plant wanes or dies, and it is necessary to renew the pasture, which entails further costs and work."

So the farmers did the math and the money doesn't work.

Scientists in this article seem very focused on the climate aspect of it while the farmers themselves are going to be focused on the bottom line. Farmers are not going to entail extra costs if they don't have to much the same as any other business owner.