A step in the right direction

I've been listening to a lot of talks lately about farming practice and Permaculture, partly in relation to  my own research for writing about a speculative world in 2070, and partly because of the amount of information revealed to us all everyday about how we are - through overuse of pesticides, petrol-based fertilisers etc - basically killing the surface of our one and only human home - and I'm not one of the folk who think we'll just piss off to Mars when this globe's kicked us off.
Therefore, I was really excited to find on one of my favourite dog walks up in the hills that some enterprising and sensible bod had introduced their flock of sheep and lambs into a huge area of vine fields - fenced off and patrolled by one of the calf-sized sheep dogs of this region, the Great Pyrenean hound, or Patou, in local speak.
What could be more sensible? The sheep eat the weeds - usually treated with roundup or some similar poison, (weeds, not the sheep) and then the animals crap thus fertilising the soil . . . It's beautiful in its simplicity and a joy to see rather than some tractor grunting up and down the striped fields spraying clouds of death-juice into the atmosphere.