Paleo Permaculture reply on land use and grain cropping systems

Comment I posted in regards to paleo permaculture, on a blog post at robbwolf.com:

As a farmer, I need to point out a couple missing inputs in this equation. Don't get me wrong, I found your article because I'm very interested in the idea of paleo permaculture, but for rigor's sake:

(1) The square footage per bird you give does not include the growing of grains for feed or the land necessary to let them range freely. While wildly variable, a standardized metric for free-ranging birds might be 12 per acre, which comes out to 3,600 square feet per bird. Growing the feed you need for 12 laying birds might take 1/3 of an acre, which is 1,200 square feet per bird of grains, corn, and legumes, and about twice that if you get rid of the corn and use predominantly cereals (wheat or barley). It would take the same space and poundage of feed for 100 broilers, which means you could eat about 2 per week.

(2) You neglect fertility requirements. Vegetables and intensive staple crops like corn, potatoes, and sweet potatoes require far more in the way of compost and minerals than extensive crops like grains do. Wheat is the hungriest cereal, but even it requires less fertility than "garden" crops, and barley, rye, and oats require far less than wheat.

(3) Grains have traditionally had their role on integrated subsistence farms. We can graze most grain crops at least once (with animals) when they're young and flush and still get a good yield. Animals can clean up the crop residues, and munch undersown clovers after the crop's been harvested. Straw is a useful farm material as mulch, animal bedding, or even for building or roofing.

I think a paleo permaculture homestead -- or even farm -- is a very cool idea, but it does not necessarily lead to a smaller footprint on the land. What is true is that you do away with the processing difficulties around grains, and when it comes to being a homesteader, that processing time is no joke, nor are those tools cheap which make it easier.

I think the ideal paleo approach would involve cows or other grazers, because you don't need to grow feed. Moreover, pasture is the perfect rotation with intensive garden land -- 4 years in pasture, 4 years in garden. But that, again, requires a lot of land, about 2 acres per full-grown cow. You get about 300 lbs. of consumable meat per cow when all is said and done, which should be more than enough for one person, but you need a big freezer to keep it in.

I hope this furthers the discussion. These numbers are all very rough because in reality they vary by climate, soil type, water access and so on, but they are pretty solid middle-of-the-road figures.