| Crop
diversity embraces the great variety within and
between crops and their wild relatives. Not only are
there hundreds of species of crops - from wheat to carrots
to mangoes - but each species may also have hundreds
or thousands of varieties containing subtle yet important
genetic differences. These varieties evolved over thousands
of years in a dynamic interaction between nature and
farmers’ careful selection and breeding.
Each crop variety may be adapted to a particular type
of soil, climate and growing season. Its genes may endow
it with traits needed by farmers: disease resistance,
cold or heat tolerance, special taste or nutritional
qualities. These qualities provide farmers and plant
breeders with raw materials to improve their crops and
adapt them to changing environmental conditions.
For example, farmers have adapted varieties of maize
that flourish in the Brazilian prairies and the northern
Mexican deserts, in the mountainous highlands of the
Andes and the islands of the Philippines. Different
varieties of maize may be particularly high in protein
or good for making tortillas, grits or flour.
Why We Need New Crops
Agriculture is already astonishingly productive by traditional
standards, yet output must roughly double in the next
50 years just to keep pace with rising population. This
must be achieved in the face of changing climate, diminishing
resources, and global conflict. Then, yields sufficient
to nurture 10 billion people must be sustained century
after century into the future. This can only be achieved
by providing a steady stream of new crop varieties that
collectively must yield more than ever before and under
harsher conditions--conditions that are unprecedented
in history. The raw materials for these new crops are
the genes that shape their form and behaviour. And the
vast majority of those genes must be derived from existing
plants--modern varieties, ancient ‘landraces,’
and the wild relatives of crops. Yet these vital crop
resources have been disappearing at a terrible rate
over the past century, even though much has been done
to stop the extinction over the past few decades, not
least by the Future Harvest Centres but also by governments,
academic institutions, and private companies. That in
a nutshell, is the problem: the loss of crop diversity.
It affects us all.
The world’s population stood at around two billion
(two thousand million) in the 1920s, had risen to three
billions by the 1960s, and now stands at billion. United
Nations demographers predict that numbers will rise
to perhaps 10 billion by around 2050, and should then
level off (simply because so many people today are opting
to have smaller families).
Human beings are large, voracious creatures; collectively,
thanks to farming, we have long since broken the ecological
law that says that ‘big, fierce animals are rare’.
We have already farmed most of the land that is worth
farming and although we continue to encroach into ever
more marginal regions we are now losing at least as
much land as we are gaining to the growing cities and
roads. So on the present farmed area, or perhaps on
less, we have to roughly double present output and then
maintain that new high level for century after century.
At present, we do produce enough for the six billion
people on the Earth but even so, for various reasons,
in 1997-99 an estimated 815 million (more than one in
eight of all people) were chronically undernourished.
Undernourishment is in turn linked to poverty. Around
1.2 billion people worldwide (one fifth of the world’s
total) now live on less than $US1 per day.
The effects of changing climate and diminishing resources
can only be guessed, but scenarios far short of the
worst that are conceivable are still very sobering.
Today, fresh water accounts for less than one per cent
of the world’s total water supply and is diminishing
apace, largely through pollution. Notably, about 20
percent of the world’s irrigated land is now salinated;
nearly two million hectares are lost to excessive salt
each year. Irrigation has brought huge areas of wilderness
into production--17 percent of all cropland is irrigated,
and it yields 40 percent of all the world’s food--but
irrigation clearly brings problems of its own and can
no longer be seen as a panacea. The world’s best
topsoils are disappearing in the wind and in the rivers.
Some countries, like China, are acting concertedly to
stop the erosion but, worldwide, the battle is being
lost. FAO estimates that with current practices, 140
million hectares of high quality soil will be degraded
by 2010, mostly in Africa and Asia.
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