The breakup of monopolies is the only viable recommendation. He missed a big one however -land ownershop monopolies. The others he's looking at the symptoms not the cause.
Fertilizer/pesticides usage is causing runoff because we are farming more ground than we need to. We are also farming using the wrong technology and locations. The highest yielding areas are arid regions with irrigation/high tunnels. It's physics and plant physiology. Arid regions = more light and heat. A lower disease, weed, and insect pressure is a nice addition. The limiting factor is water storage of course.
Moving farming away from high rainfall zones would eliminate most agricultural runoff. This would take massive investment into irrigation systems to move water hundreds of miles away (Mississippi to West Texas, New Mexico etc...) It would also completely interrupt the existing infrastructure. However it would reduce our land footprint by 80% or better.
Reducing our total land footprint would also help preserve the wild types/land races giving them space to grow.