an acre) that may soon be all that is available to each
man, woman, and child living in developing nations (see
Appendix 2). Soon we simply will not have the luxury of
taking nutrients from one soil to feed another.
With about 33 to 49 years’ worth of topsoil remaining
in the world, learning how to enrich, improve, and
maintain soil—in a way that is sustainable—is of vital
importance if we as a species are to survive. If current
agricultural systems can only provide food for about a
century before the soil is depleted, they clearly are not
sustainable. Ancient civilizations sustained their soils to
feed large populations for lengthy periods of time.
China’s soils, for example, remained productive for
4,000 years or more until the adoption of mechanized
chemical agricultural techniques that have been
responsible, in part, for the destruction of 15% to 33%
of China’s agricultural soil in the period from 1950 to
- Many of the world’s great civilizations have
disappeared when their soil’s fertility was not
maintained. Northern Africa, for example, used to be the
granary for Rome until overfarming converted it into a
desert, and much of the Sahara Desert was forested until
it was overcut.
Learning from the past and present: The Chinese biologically miniaturized
agriculture and grew food organically by closely spacing plants and maintaining soil
fertility (using nutrient- and carbon-containing compost) for thous-ands of years
without depleting their resources. By 1890, this process enabled the Chinese to grow
all the food for 1 person on about 5,800 to 7,200 square feet, including animal
products used at the time.