Agriculture Reference
In-Depth Information
though it creates fertilizer from thin air, is not without its costs, as it requires energy, quite
a lot in fact. It takes roughly a tonne of coal to produce one tonne of sulphate of ammonia
fertilizer (213 kg N - sufficient for about two hectares of wheat). The European Fertilizer
Manufacturer association states that 'of all the energy used to produce wheat ' including
other fertilizers and all tractor use, 'approximately 50 per cent is needed to produce, trans-
one per cent of the world's manufactured energy is devoted to ni-trogen fertilizers which
are used in the production of about half the world's food.
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The introduction of chemical fertilizers put an end to the requirement to maintain the
balance between animals and crops - Postan's 'shifting frontier between grass and grain'
- and hence to mixed farming. In theory the application of supplementary quantities of
chemical fertilizers in situations where a good balance between animals, legumes and grain
could not easily be achieved might have been beneficial, and energy well spent. But, of
course, that is not how things happen in a capitalist society. Muck needs shifting and that
requires labour. Labour is expensive, while chemical fertilizers are easier to apply, and like
most fossil-fuel based products cheap in relationship to the energy they consume. An arable
farmer who moved over to chemical fertilizers could forget about livestock completely,
cut out the complicated, labour-intensive routine of managing animals and their muck, and
concentrate on a relatively simple annual cycle of ploughing, scattering and harvesting.
The result was the decline of the mixed farm, which was replaced, particularly in the US,
by monocultural grain farms, and their corollary, the feedlot. Since livestock was no longer
an integral part of arable farming, the two activities could be sited hundreds of miles apart
and grain from the prairies shipped to huge factories where livestock could fattened and
processed in their thousands. Manure became redundant, and muck instead of being an es-
sential component of the farming cycle, became a waste disposal problem. The larger and
more industrialized the farm or feedlot, the bigger the problem.
The problem has recently spread to developing countries, particularly China. In the 17th
century, 34 per cent of China's manure came from the human residents and 47 per cent
of synthetic fertilizer applied to crops was negligible. Since then the use of synthetic nitro-
gen has increased spectacularly, as has per capita meat consumption and the size of cities.
By the mid 1990s livestock factory farms on the edge of cities, non-existent before 1979,
were supplying 15 per cent of China's pork, 25 per cent of its eggs and 40 per cent of its
broiler hens.
At a conference in Hangzou held in 2006, Chinese academics warned that these farms
were producing 'huge animal wastes, which, mostly discharged untreated, have caused ser-
ious pollution to water and air'. Wu Weixiang, a professor at Zhejiang University, repor-
ted that in Zhejiang province on the east coast the livestock industry produced 26 million
