In the book, things are rather clearer. The Shire's agriculture is still the most obvious, but it does go on elsewhere. For instance, The Lord of the Rings tells us that the Pelennor Fields, the hinterland around Minas Tirith, are farmed
Pippin could see all the Pelennor laid out before him, dotted into the distance with farmsteads and little walls, barns and byres
and even Mordor's provisioning is explained:
Neither [Sam] nor Frodo knew anything of the great slave-worked fields away south in this wide realm, beyond the fumes of the Mountain by the dark sad waters
Nevertheless, there are peculiarities. Tolkien's introduction makes it clear that LOTR is set in the remote past in "the North-West of the Old World" - see Strange Maps, Where On Earth Was Middle-earth?. So what is Sam doing in the Of Herbs and Stewed Rabbit episode wishing for "taters", a New World vegetable? And excluding outright magical drinks and foods such as miruvor, ent-draught and lembas, what's strange is the remarkable lack of exoticism in food. Tom Bombadil, in the middle of a forest, serves up "yellow cream and honeycomb, and white bread, and butter; milk, cheese, and green herbs and ripe berries". At Ithilien, Fordo and Sam get served wine, bread and butter, salted meats, dried fruits and "good red cheese". In the buttery of Minas Tirith, a city whose location more or less corresponds with Italy and which has trading routes to further south, Pippin gets "bread, and butter, and cheese and apples". There's a great deal more about hobbit diet here: Well-stocked Larders: Food and Diet of Hobbits (Stephanie Green, Strange Horizons, February 2008) concludes that "It seems his choice of foods is more influenced by his representation of hobbits as yeomen of the English pastoral tradition". It also appears that Tolkien was projecting his own tastes on to his created world: The Origins of Tolkien's Middle-earth For Dummies mentions that
Even Tolkien referred to himself as a hobbit ("in all but size") for his love of pipe-smoking, gardens, plain and simple food, peace and quiet, his dislike of mechanized farmlands and traveling, and his fondness for wearing ornamental waistcoats
The English "plain food" stereotype really comes from dismal post-WW1 cuisine; English historical food hits the garlic and spices far more than you'd expect. Whatever - Middle-earth would leave me dying for a curry. (There are a number of cookery guides around, such as Emerald Took's Regional Cooking from Middle-earth: Recipes of the Third Age - reviewed here - but they seem to take off in decently spicy directions completely unmentioned in LOTR).
It's unknown how Dwarves (living underground in big halls in the mountains) get their food, nor the Elves: though Ents, Elves, and Eriador: The Environmental Vision of J.R.R. Tolkien (Matthew T. Dickerson, Jonathan Duane Evans, John Elder, University Press of Kentucky, 2006, ISBN 0813124182) has a whole chapter - Horticulture and the Aesthetic of the Elves - arguing plausibly that the visible details of processed products such as miruvor and lembas imply highly sophisticated agriculture, viniculture and processing behind the scenes. Ents, Elves, and Eriador is based on a broader thesis that Tolkien's works "demonstrate a complex and comprehensive ecological philosophy."
The ecology of Middle-earth ... brings together three potent and convincing elements of preservation and conservation?sustainable agriculture and agrarianism, horticulture independent of utilitarianism, and protection of unspoiled wilderness
This may be partially so, but in many ways this doesn't wash. Firstly, Middle-earth seems extremely thin on biodiversity, and flora/fauna food production appropriate to region, cornerstones of a sustainable ecology. In the book we see a "mumakil" (an elephant) once, and that's about it. Elsewhere, it seems the same English staples appear everywhere. Where, for example, is the horsemeat and kumis you'd expect in a horse-focused warrior culture like Rohan? (compare cuisine of Kazakhstan). Secondly, Middle-earth is full of trappings implying a higher level of industry and agriculture than is actually seen. Arms and armour don't make themselves: even small forges need charcoal (hence charcoal-burning, a staple of pre Industrial Revolution Europe). The Dwarves' focus on mining and smelting would need even more. Hobbits engage in conspicuous consumption - at least six meals a day, with a deal of leisure time - quite inconsistent with the amount of work that would be to grow and harvest the stuff they eat. They also have plenty of domestic accoutrements - cups, plates, cutlery, garden shears, books, glasses, bottles, convex mirrors, waste paper baskets, umbrellas, a post office, the luxury of flower gardens, and so on. Life in "more or less a Warwickshire village" of the late 1800s (Tolkien's description cited in the Stephanie Green article above) might well have had such fixtures, but only because someone somewhere more industrialised was making them.
Although the hobbits aren't responsible for these, Gandalf's complicated fireworks (in both book and film) imply some highly sophisticated knowledge of chemistry, a point noted by Michael Moorcock, who commented to Ansible (174)
how come these early industrial revolution kulaks, with sophisticated metal working skills, gunpowder, focusing lenses and advanced printing methods, couldn't make one simple f***ing cannon and blow the bad guys off their keeps in a trice? Jesus, they could put an intercontinental ballistic missile together with the resources I spotted in hobbitville without even thinking about it
Moorcock is a long-standing critic of Tolkien. In Epic Pooh (originally in Wizardry and Wild Romance, A Study of Epic Fantasy) he argues that LOTR is essentially "safe" (for instance, in turning away from the reality of death, which is integral to other epics - an example I can think of is how the ailing Frodo, the elderly Bilbo and the on-borrowed-time Gandalf, who ought realistically to die, are instead packed off to emigrate in a ship as a kind of sanitized surrogate death).
Much as I enjoy the films (and, on re-reading them, the books) I find it hard to disagree with Moorcock's argument that the world of The Lord of the Rings is a Middle England NIMBY agrarian fantasy: Tolkien's heroes have all mod cons with the necessary agricultural and manufacturing infrastructure airbrushed out; while Mordor's inhabitants and Saruman, who openly manufacture stuff, are the villains. It probably just comes down to Tolkien's well-known gripes about Birmingham encroaching on Sarehole, where he grew up. I kind of wonder if, despite the historical etymology for "orc" = ogre (OED, 1605 J. SYLVESTER tr. G. de S. Du Bartas Deuine Weekes & Wks. II. i. 337 Insatiate Orque, that euen at one repast, Almost all creatures in the World would waste.) Tolkien also had in mind "oik" (OED, "An uncouth, loutish, uneducated, or obnoxious person; a yob (esp. with connotations of lower-class origin") - the latter, cited from 1925, is well within the etymological time-slot. Then again, without evidence, it could easily be a false friend.