Whereas the initial impact of cheaper transport was upon agricultural produce, the growing dependence of farmers upon purchased inputs was made easier by these advances. In early nineteenth century England canals made possible the movement of coal for threshing machines, pipes for under-drainage and lime and superphosphates; it was the extension of the railways which further cheapened the movement of these goods. But the introduction of the petrol-driven motor vehicle has been even more significant, for fertilizers can come direct to the farm and be more easily moved around the farm and bulk tankers can collect milk. Indeed, much of the change in agriculture over the last 200 years would have been impossible without improvements in transport.