Today I got a wicked good workout on a landscaping job. I bid it out at 5 hours of labor and I was to mulch two large areas. The areas worked out to about 11 Cu yards of material for good coverage which is two short loads with B.A.R.T. (Big Ass Red Truck). Dropped the kids off at school and emptied my municipal site of chips – about 7 yards. They were wet for the 2” of rains and heavy as hell. Also, the bed on B.A.R.T. is about 44” up so that is a hefty throw. Took a solid hour of throwing chips with a manure fork (.5 cu ft a throw) with a few breaks to push the chips deeper into the bed. Then it was off to the job site. I had forgot my mulch barrow at the farm which has a 10 cu ft payload and dual wheels – for reasons I don’t understand I choose not to get it and use my rock barrow with its 5 cu ft metal barrow. Those of you good with quick math now realize that I just doubled my trips, but I wasn’t real keen on a 25 mile detour in a 7 mpg truck. I literally thought “it’ll be a good workout” ad its not THAT far. Got to the site and realized my memory had played tricks on me – the gardens were 75 and 125 yards from the driveway. Oi.
The long and short of the story is that 11 cu yards is about 300 cu ft. That is 60 trips in my little wheel barrow. 200 yards per trip for 60 trips is just shy of 7 miles of walking. 11 cu yards of wet chips weighs in at about 6000#’s. Did I mention that the gardens were all down (thank goodness!) a hill with a 20’ drop? I climbed 1200’ of elevation to boot.
Truth be told I had a great time – good honest work. Very little thought – this was grunt work so my mind could wander and I was able to sweat out a lot of good ideas (as well as the math in this post) whilst I was literally sweating out liters of water.
The job took about 5.5 hours, but prolly would have shaved an hour with the mulch barrow. 5.5 hours of fairly intense work – I figure about 450-500 cal an hour based on my heart rate and sweat levels compared to the gym. 5.5 hours. JESUS! That’s almost 3000 calories! Methinks that 6” Veggie Delight at Subway didn’t cut it and that also explains why I hit a “wall” at hour 4.5. Jared should give me a call if he REALLY wants to lose weight!
3000 calories. That got me thinking. When we plan average caloric intake like the USDA says on the cereal boxes, we figure –at most– 2500 calories. Even if I am rounding up a bit, that is a crap ton of energy I burned and given I kept working when I got home, it is entirely possible I hit 4000 calories today. Energy I need to eat again. Many of us have seen the caloric needs of a person touted in attempts to calculate how much acreage is needed to grow enough food to feed a person for a year. I’ve seen figures ranging from 750,000 to about 900,000 calories per person per year. In only a few cases (pretty sure John Jeavons mentions it) have I seen the author take into account that the caloric needs of someone farming (or insert physical trade of choice here) by hand has significantly higher caloric needs. Sitting in a cubicle all day and watching my daily allotment of TV, I have proven I will gain weight at 1800 calories. If I had to grow all my own food, or more likely enough for several families of 4, I will be burning significantly more calories and will likely need more land. 12 people at 850k equates to 10,200,000 calories. If we are all burning 3000+ the land needs go up by 30% as we’ll need closer to 1,100,000 calories annually.
This is why I have stressed repeatedly on this blog the need to learn to efficiently grow calorie crops without inputs. An acre of potatoes will produce at least 40,000#’ if well managed. Potatoes have about 20 calories per ounce. That works out to about 13,000,000 calories per acre. Of course man can’t life on spuds alone, but that is enough to feed 12 hungry sustainable farmers. A 5 acre farm set up to rotate cucurbits/corn/beans, onions/greens/brassicas/roots, and solanaceae (1 acre each) combined with fruiting hedgerows, and an acre in cover crop rotationally grazed by chickens could support the caloric and nutrition needs of 30+ people. The eggs from the chickens alone would add about 4,000,000 calories per year (230 hens, 200 eggs per year, 85 calories an egg), so that 30ish person figure is likely fair even without running the math on the winter squash (20,000#’s), onions (15,000#) and hedgerows. Plus you could add a cow or some goats to the pasture with no loss of eggs and we are running mono crop rather than permaculture design in most acres so we are wasting solar energy – but that is another post!
There are 470,000,000 acres of arable land in the US. True, many of those depend heavily on irrigation so lets run it at 300,000,000 acres. Divide by 5 acres and multiply by 30 people. 1.8 billion people. Add in the Ukraine, Europe, Brazil, India and China and we *can* feed the world – we need about 1.5-2 billion acres, but its gonna be close and distribution is gonna be hell to get our surpluses to India and China not to mention that Africa is already a mess.
Plus we need to build soils like crazy as the only fertilizer in 50 years will be manure and compost. Oi. Maybe next time I’ll bring an iPod to keep my thoughts from rambling…
Build soils.
Be the Change!
-Rob
Filed under: Doom and Gloom, Energy Descent, going off, Living Soils, Small Scale Agriculture, sustainable agriculture | 11 Comments »