TOWARDS A PERMACULTURE LIVESTOCK ECONOMY - MEAT: A Benign Extravagance - page 352

None of this is a problem for people who live dispersed in the countryside. Manure,
human sewage and solid organic waste can all be composted; human sewage can also be
treated on site through wet water systems, reed beds or composting; liquid waste can be
recycled through reed beds, or cured and sprayed onto meadows when the grass is about
to grow. In a predominately local economy the quantities of waste are neither too large
to cause a pollution problem, nor are they likely to deliver too little phosphorus, because
mostly they are going back to the place that they came from. Moreover, in a renewably re-
sourced economy where all disposable items are made of organic material, there is none of
the fossil-fuel derived packaging and the wretched scraps of plastic that make sweeping up
such a chore for the conscientious: we could forget about waste sorting, and return to the
carefree existence of our forefathers who could sweep everything unwanted outdoors onto
the midden, or toss it to the pigs, knowing that that was the right place for it.
With animal manure, a move away from slurry and towards dry composting would im-
prove nutrient retention. When manure is composted the methane and nitrous oxide emis-
sions are significantly lower than when manure is applied to the land as slurry, or is simply
left in a heap. 86 One Canadian researcher, Gupreet Singh, estimates that by composting ma-
nure from beef cattle, Canada could reduce its emissions of greenhouse gases by the equi-
valent of 16 million tonnes of carbon but adds that 'the slight hurdle' to persuading farm-
ers to adopt composting techniques is the 50,000 Canadian dollars needed to fit a tractor
with compost turning equipment. 87 Perhaps he should consider Polyface Farm's 'Pigaerat-
or' system where pigs are persuaded to root through beef cattle bedding by throwing grains
into it. 88 Compost is also the method of returning plant biomass to the land that has the best
record in accumulating soil carbon. A well stacked and composted muck heap ought be as
much an object of pride as a well-turned furrow, and as much a symbol of prosperity in
spring as a bulging granary is in autumn.
Another option is using the manure on the farm, including human manure, to produce
biogas for the farm and the surrounding community. According to one study, the cow ma-
nure from one hectare, in a farm anaerobic digestion unit, has the potential to produce 1,500
kwh and 1,100 kwh of heat per year (this is presumably from cows kept indoors day and
night). In Germany there are an estimated 2,500 such units on farms with an average capa-
city of 200 kw. 89 In India there were 3.67 million domestic and village sized biogas units
installed by the end of 2004, most running on cow manure, but a few using human waste.
They can be built out of brick by a competent mason, and produce gas for electricity and
lighting. 90
In Britain, however, the main incentive for building anaerobic digesters seems to be to
deal with the food waste problem. The UK's largest installation at Holsworthy in Devon,
which supplies the grid with enough electricity for 3600 homes, processes food waste from
local councils, fish processors, bakers, slaughterhouses etc; but it also trucks in slurry and