In reply to Shani:
> A grass field is not monocropped - certainly not in the way a grain field is monocropped.
Again, where do you think the majority of animal feed comes from?
> The answer to some of these problems is appropriate rotation of crops and animals over farmland.
Very skeptical about that but if you have good objective sources I'll happily have a look.
> Actually pastoral land is much more of a problem in terms of flooding, run-off, erosion, leaching of nutrients in to local water resources (eutrophication), siltation of water courses (which kills fish and other aquatic life). It is an evident problem as soon as you start removing surface vegetation (particularly during ploughing).
Ditto. I doubt all the excrements of sheep and cattle have a lesser impact on water sources. And as for agriculture that depends on how it is implemented, but pesticides are not needed, it's partly about selecting the crops most resistant to such or such pest or best adapted to such or such conditions (which is getting increasingly hard with all the patenting issues). Regarding ploughing no-till farming seems to be an interesting alternative?
> I disagree. Furthermore you might prefer "wild nature with wolves, lynxes and bears" and this would indeed be interesting. But none of those animals are herbivores so how are you going to feed them? From a food point of view, I prefer my idea of humans being the meat-eaters in this arrangement.
You may disagree but the number of deer in our forests is nowhere near the number of animals we currently eat (about 60 billion land animals worldwide per year and 100 billion fish). There's enough of them for apex predators though.
> And that is the land on which bird-life, foxes, badgers, mice, voles, frogs, newts, beetles & bugs etc... all survive on without risk of poisoning from pesticides or the slice of the plough!
Raptors, mice, voles, foxes, bustards... will arguably be as (or more in the case of rodents?) common in grain fields. Badgers live primarily in forests, as do many birds. Frogs, newts... are rather subordinate on wetlands. I agree though that larks, shrikes and other birds prefer open spaces, but perhaps they weren't "meant" to reach the numbers they've reached back when everything was covered with forests. Or they just adapted and could just as well adapt back to living in forests. One key issue no matter the food source is the rehabilitation of hedges.