… it is our work with living soil that provides sustainable alternatives to the triple crises of climate, energy, and food. No matter how many songs on your iPod, cars in your garage, or books on your shelf, it is plants’
ability to capture solar energy that is at the root of it all. Without fertile soil, what is life?
—vandana shiva, 2008
Throughout history, humans have worked the fields,
and land degradation has occurred. Many civilizations
have collapsed from unsustainable land use, including
the cultures of the Fertile Crescent in the Middle East,
where the agricultural revolution first occurred about
10,000 years ago. The United Nations estimates that 2.5
billion acres have suffered erosion since 1945 and that
38% of global cropland has become seriously degraded
since then. In the past, humankind survived because
people developed new lands. But a few decades ago the
total amount of agricultural land actually began to decline
Figure I.1. Reaching the limits: Marginal rocky land is put into production as new land could no longer compensate for the loss of
in Africa.
old land. The exhaustive use of land is combined with
break out in 2008. Some countries with limited water
increasing populations; greater consumption of animal
or arable land are purchasing or renting land in other
products produced in large-scale facilities, which creates
countries to produce food for the “home” market.
less efficient use of crop nutrients; expanding acreages
Nevertheless, human ingenuity has helped us
for biofuel crops; and the spread of urban areas, subur-
overcome many agricultural challenges, and one of the
ban and commercial development, and highways onto
truly modern miracles is our agricultural system, which
agricultural lands. We have now reached a point where
produces abundant food. High yields often come from
we are expanding into marginal lands—like shallow
the use of improved crop varieties, fertilizers, pest control
hillsides and arid areas—that are very fragile and can
products, and irrigation, which have resulted in food
degrade rapidly (figure I.1). Another area of agricultural
security for much of the developed world. At the same
expansion is virgin tropical rainforests, which are the last
time, mechanization and the ever-increasing capacity of
remnants of unspoiled and biologically rich land. The
field equipment allow farmers to work increasing acreage.
rate of deforestation at this time is very disconcerting;
Despite the high productivity per acre and per person,
if continued at this level, there will be little virgin forest
many farmers, agricultural scientists, and extension spe-
left by the middle of the century. We must face the reality
cialists see severe problems associated with our intensive
that we are running out of land. We have already seen
agricultural production systems. Examples abound:
hunger and civil strife—especially in Africa—over limited
• With conventional agricultural practices heavily
land resources and productivity, and a global food crisis
dependent on fossil fuels, the increase in the price of
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Building SoilS for Better CropS: SuStainaBle Soil ManageMent