Archive POT-MOD-L: file log9502, part 1/1, size 6071 bytes:
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Basic Questions About Sustainable Agriculture
The two biggest questions about sustainable agriculture seem to be:
1. what is it?
2. how do we get there?
I study the irrigated potato production system in the arid/semi-arid
areas of the inland northwestern US (Eastern Washington & Oregon,
Southern Idaho). This may not be a particularly sustainable system
as now practiced, with high energy use for daily irrigation, constant
application of fertilizers and pesticides, possible groundwater
pollution, numerous tillage operations, vulnerability to wind erosion
at planting and after harvest. However very high yields are produced;
about 90 tons/ha (35 ton/ac) of marketable tubers. I will discuss
above the two questions in terms of my research interests.
1. What is a Sustainable Production System?
So what is sustainable potato production? One answer might be the
potato, maize, beans rotation practiced in the Andes mountains
(Agron. J. 83:2-10, 1991) which has improved the soil quality over
the last 500-1500 years, but which produces only a fraction of the
yield and profit produced by the rotation in the northwestern US (at
a fraction of the cost in terms of energy use).
Perhaps a sustainable production system for the dry interior of the
northwestern US will include:
disease and pest resistant cultivars (not yet available);
precisely timed and minimal applications of water and fertilizers
(based on computer software under development);
use of cover crops and minimal tillage to build soil quality and
prevent erosion;
control of weeds by filtering seeds out of irrigation water,
inducing germination of weed seeds when they can't survive
(unknown chemical treatment?);
enhancement of insect herbivores that don't eat potatoes
(resistant potato cultivars);
choice of rotation crops;
precisely timed use of herbicides and tillage.
Energy costs for irrigation (pumping to the field, loss of hydro
power down river, effects of reduced river flow on fish and other
riparian life), for manufacture and application of fertilizers and
other chemicals, for manufacture of farming equipment, and for tillage
(including handling of crop residues, i.e. stems etc. not harvested),
would have to be compared to the value to society of using the energy
for food production or other uses somewhere else as well as in terms
of profitability of the farming operation for the producer. Of course
other possible uses of energy, water, and land should also be weighed
against agricultural use in terms of their value to society.
Certainly there will be innumerable variations of sustainable systems
depending on crops, soils, climate, geography, markets, and social
structures.
2. How do we get to a Sustainable Production System?
Even if all the components were available, the above description of
a production system is not a precise definition that could be
implemented or even easily evaluated. Farming is a complex, tricky
business. Little unexpected problems are always showing up whenever
some new combination of practices is tried, problems that must be
solved immediately or the crop will be lost or severely damaged. Ask
any farmer!
A radically new production method must be tested successfully on both
a small scale and on a large commercial scale before it can be adopted
widely. Both levels of testing are guaranteed to reveal many
unexpected surprises, mostly unpleasant. If a new production system
is mostly put together from components that have been successful in
other situations, then unpleasant surprises may be minimized but not
eliminated.
Many farmers are extremely good at developing new techniques or
adapting them to their systems, especially if they have a comfortable
profit margin. This innovative capacity should be regarded as a
valuable resource in our movement toward sustainable systems.
Government policies should encourage farmers to try new things that
may provide components of future sustainable systems and discourage
(usually gently) things that are clearly not going to be part of
sustainable production. Trying to change our agricultural
production systems too rapidly may result in reduced production,
increased cost per unit of production, bankruptcy of many farmers
(i.e. wide spread starvation in third world countries), and
unexpected ecological damage. It could also result in some
reduction of the innovative capacity of farmers as they struggle to
just survive for another season. Of course changing agriculture too
slowly results in continuing loss to soil, water, energy, and
biodiversity resources.
I think this means that we should plan on getting into sustainable
agriculture gradually, by a long series of trial and error steps. It
also means that we must not waste a lot of time in getting started in
that direction.
What is the role of government funded research in arriving at
sustainable agricultural systems? It should include initial
development of completely new techniques and resources (equipment,
methods, genetic material). It should also be aimed at filling gaps
in our understanding of how components of biological systems interact
(systems research), so we will have a better idea how to put
components together into coherent production systems (systems
engineering).
Tom Hodges, Cropping Systems Analyst, thodges@beta.tricity.wsu.edu
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