Title: GEOG 3000 Resource Management Sustainable farming systems
1GEOG 3000 Resource ManagementSustainable
farming systems
- M.D. Lee CSU Hayward Winter 2004
2Agricultural Land
- Agroecosystems are defined as areas in which at
least 30 of the land is used for crops or highly
managed pasture (WRI 2001). - Some 28-37 of the worlds land surface currently
seems to meet this criteria based on satellite
data. - Thus about 8-10 of the worlds total land
surface is in use for crop or livestock raising,
leaving 2-4 left for expansion if the global
estimate of 12 potentially farmable land is
accurate. - Global farmland area increased 8 from 1966-96
although this masks conversions to and from
farming. - Industrialized regions lost over 100 million
acres of farmland to urban sprawl in this same
period.
3Urban Sprawl growing houses instead of crops
4Crop genetic resources
- It is estimated that only 15 plant and animal
species currently provide 90 of the worlds
food, even though there are 30,000 plants
(perhaps 75,000) with edible parts. - Currently, enough food is produced on the planet
to provide a per capita diet of around 2,750 kcal
per day (WRI). - Four staples (wheat, corn, rice and potatoes)
provide the majority of crop production and
calories, but we are using a decreasing number of
increasingly genetically homogenous varietals
each year (especially with rice). - Giant agricultural multinationals are
increasingly turning to genetically engineered
species (GMOs) to boost yields and decrease
production costs (especially soybeans corn).
5How will we feed ourselves each day?
Meat eaters?
Vegetarians?
6Eating up the food chain
- Between 1995-2020, the demand for cereals like
rice, corn and wheat will increase 40, 85 of
this in developing countries. - Much of this is in response to the expected 58
increase in global meat demand, again 85 of this
will be in developing nations. - Ironically, food demand increases will be even
higher if we succeed in global economic
development since greater affluence leads to
greater demand for food, especially meat. - Meat production requires greater production of
grains for feed, a loss of overall calories due
to the trophic energy losses up the food chain.
7How do we get our food?
- In industrialized nations like the US, we rely on
monoculture farming (now called conventional
farming) that uses intensive energy, water,
pesticide and fertilizer input on
agribusiness/factory farm systems. - Excess production is exported and feeds about 1/3
of the rest of the world. - We also import our food from developing nations
where the best land is used for similarly
intensive plantation agriculture for export
(although cheap labor is often substituted for
machinery), often through multinationals like
Dole. - Because of surpluses in the US and Europe, excess
production is dumped at low cost on foreign
markets, destroyed, purchased by govts. and given
away or subsidized, or else farmers are paid not
to plant a crop.
8Farming in less developed nations
- More than 2.7 billion people worldwide get their
food from small family farms using animal
traction, hand labor and green manure (animal
waste or nitrogen fixing legumes plowed in). Some
1.4 billion rely on subsistence level farming. - In much of S. America, Africa and SE Asia, slash
and burn is still practiced by small farmers,
where possible on a shifting agriculture basis. - With the best land used for export crops, farmers
move on to steeper slopes better suited to
forests and soil erosion is becoming a major
problem. - When soils degrade, increasingly there is nowhere
to shift to and farmers give up the land, move to
virgin forests elsewhere or migrate to cities.
9Hillslope Farming
With flat land running short, farmers are forced
up onto hillslopes. If they invest the time and
resources in terracing and other erosion
controls, farming can be sustainable.
If farmers do not anchor the soil with adequate
vegetation cover or physical structures like
terraces, then erosion can quickly result and
farms must be abandoned..
10The Future of Farming
- The world needs continued improvements in farming
productivity, particularly because good farmland
is being converted to urban land uses (see WRI
2001 p56). - Improved farming efficiency is still possible
from multiple cropping, intercropping, irrigation
and land reform (see Machakos example from Kenya
in WRI 2001). - Sustained higher yields could come from better
soil fertility management wider access to
chemical fertilizers (short-term) and the use of
green manure, composting and erosion control
(longer term). - More secure food supplies can be assured by more
efficient post-harvest storage and better
distribution. - Many believe a return to more traditional farming
and away from conventional agribusiness is
required (for a developing country example, see
Cuba study in WRI 2001).
11Applying Sustainable Techniques in the Developing
World
- Cuba has been doubling and tripling its food
production through intensive organic techniques
on small farms.
- Kenyans have reversed years of decline in food
production through integrated soil and water
management on family farms
12Sustainable Agriculture
- Broadly defined, sustainable agriculture is where
farmers introduce systems to profitably maintain
an appropriate production of high-quality food
while conserving resources in an environmentally
and socially beneficial way. - Farming subsidies and short-sighted
profit-seeking often lead to damaging monoculture
and unsustainable practices and can cause wasted
surpluses. - Heavy indebtedness can lead farmers to farm
unsustainably, causing erosion, environmental
damage. - A vicious cycle results in which farmers stake
more and more on achieving high, predictable
yields year after year to pay for increasingly
high input costs (true at all levels).
13Global Agricultural Priorities
- A combination of six basic goals need to be
implemented to sustain agricultural production
and meet growing global food needs worldwide. - Protect existing productive soils from erosion
and urbanization (difficult when cheap imports
make local farmland worth less). - Increase plant productivity per unit of land
planted. - Reduce harvest losses from pest damage
(especially through integrated pest management
that minimizes pesticides). - Expand the total land area being farmed.
- Develop new crops that exploit underutilized land
resources (e.g. salt tolerant crops) hybrid or
GMO though? - Improve global food storage and (re)distribution.
- How best to do this without ecological damage is
a subject of intense debate in industrialized and
developing nations.
14Science and sustainability
- Society is weighing up the role that scientists
can play in boosting farming productivity both as
an alternative to and a compliment to other
methods. - Biotechnology and genetic engineering are often
touted as the solution to world food needs. - Genetically modified foods (GMOs) are already
very common on US farms and in supermarkets. - However, in Europe, they are called Frankenfoods
and are vigorously being protested as unhealthy
and ecologically damaging and thus unsustainable. - We have and will see more pest resistant and
other productivity enhancing genes added to
crops, more use of growth hormones in
livestock/dairy, and more widespread cloning of
the top milk and meat animals in the medium term. - Many believe the GMO varieties, if cheap enough,
could provide the biggest benefits in the
developing nations.
15The FrankenFood Debate
- Canadians, Europeans and other nations
environmentalists publicize their opposition to
the release and use of GMOs.
16Some Obstacles to Sustainability
- Cropland and production expansion is hampered in
many regions of the world by soil erosion, lack
of water, air pollution and urbanization of prime
farmland. - For example, in China, more than 1 million acres
of farmland has been paved in the last 30 years. - Some believe bioengineering could result in
unforeseen biological catastrophes from
uncontrolled mutations of GMOs as well as
possible human health effects. - Increased demand for meat in developing countries
in relation to cultural changes and economic
prosperity could reduce total calories produced
from farming by a large , exacerbating
inequalities. - Modern farming productivity is intensely
dependent on cheap, abundant fossil fuels for
energy and for chemical inputs.