permaculture

["Nicholas Roberts, Permaculture.coop" <permaculturecoop@gmail.com>]

http://www.rand.org/pubs/research_briefs/RB9263/index1.html
http://www.rand.org/pubs/occasional_papers/OP179/

This research brief describes work done for the RAND Frederick S.
Pardee Center for Longer Range Global Policy and the Future Human
Condition in Perennial Polyculture Farming: Seeds of Another
Agricultural Revolution? by James A. Dewar, OP-179-RPC, 2007, 38 pp.
(Full Document).

This product is part of the RAND Corporation research brief series.
RAND research briefs present policy-oriented summaries of individual
published, peer-reviewed documents or of a body of published work.

Copyright © 2007 RAND Corporation


Perennial Cornucopia

Planning the Next Agricultural Revolution

Abstract
Perennial polyculture farming (PPF) offers great benefits for the
environment and humankind. Farmland would be reengineered to emulate
ecosystems, such as prairies, that require no maintenance yet provide
food, continuous ground cover to minimize erosion, and natural methods
to fertilize crops and control pests. Food production would be
sustainable, the undesirable effects of modern agriculture would
decrease, and poverty and hunger would be reduced. While the promise
of PPF is not yet widely recognized, early steps to explore its
feasibility are under way.

Ideally, improved agricultural practices should continue to increase
food production while reducing environmental damage and other
undesirable effects of current methods. RAND Corporation researcher
James Dewar explores an innovative approach, called perennial
polyculture farming (PPF), that could be an important step toward
realizing that goal. PPF differs from most farming in two fundamental
ways. Typically, today’s agriculture centers on planting and
harvesting a single species of annuals (such as wheat). PPF involves
growing multiple species of perennials on a single section of land.
Proponents of PPF believe that its widespread adoption could reap
significant benefits, both for the environment and humankind.

One natural model of thriving perennial polycultures is the prairie
that covered much of the Great Plains in the United States before
wheat farming was introduced. Prairies, consisting of many kinds of
perennials growing together, required no maintenance, yet provided
food for various animals along with continuous ground cover that
minimized erosion, legumes that provided fertilizers, and natural
measures that controlled pests. PPF involves reengineering such
natural ecosystems as prairies for farming purposes. Its proponents
envision land that thrives the way these ecosystems did before humans
arrived but is designed to rival the productivity of modern industrial
agriculture.

Polycultures and Perennials

Many farmers already grow more than one species of crops on a plot of
land. Such polyculture farming can be either sequential or
intercropped. The sequential approach means planting crops in the same
space in different seasons. Intercropping means having different crops
grow on the land at the same time. In Mexico, for example, it is
common to plant maize, beans, and squash on one plot. Growing a
variety of plants together with no distinct row arrangement is mixed
intercropping, a situation that resembles natural ecosystems such as
prairies. It is mixed intercropping of perennials that offers the
greatest sustainability benefits and is central to the PPF approach.

Perennials currently produce fruits and nuts but do not produce
significant amounts of cereals. Since cereals account for at least
half of dietary energy worldwide, PPF can play an important role in
global agriculture only by changing the way cereals are produced.
Among other challenges, such a step would require developing perennial
grains that would thrive in mixed intercropping and could be easily
harvested.

Environmental Benefits

Successful PPF would have powerful environmental effects, addressing
many problems connected with existing agricultural methods. The
perfect “reengineered prairie” would provide year-round ground cover
to minimize erosion by wind and water. This constant ground cover
would also diminish the need for irrigation and its huge thirst for
water resources. Soil degradation caused by depletion of minerals
and/or contaminations by pesticides, herbicides, and other means would
be reduced because the polycultures would produce their own soil
nutrients and provide their own pest control. Contamination of
freshwater systems would likewise be curtailed by lower use of
fertilizers, pesticides, and other chemicals. This reduced use, in
turn, would help prevent such environmental problems as ocean dead
zones, caused in large part by agricultural runoff. Additionally, PPF
would help reverse biodiversity loss.

Social Benefits

PPF could also lead to reductions of hunger and poverty, to
improvements in health and education, and to lower energy use.
Agricultural productivity in developing countries is often inadequate
because of poor soil, erosion, and insufficient irrigation, as well as
lack of money for seeds, fertilizer, and pest control chemicals. The
environmental benefits of PPF outlined above would increase
productivity by reducing or eliminating most of these problems.
Greater productivity would alleviate undernourishment among children
and potentially improve the lives of women whose lack of education
stems in part from increased responsibilities in agricultural work. In
developed countries, PPF would save energy by cutting reliance on
heavy farm machinery and fossil-fuel-intensive fertilizers and other
chemicals.

Feasibility of PPF

While PPF may appear fanciful, modern farmers already use techniques
that emulate PPF methods: They rotate crops to limit the need for pest
control chemicals and fertilizer, use cover crops to improve soil
quality and reduce erosion, use low-till farming to increase water
retention, and so on. In recent years, institutions such as The Land
Institute and The Rodale Institute have been conducting research on
perennial polycultures to see if the PPF approach could be a feasible
alternative to monoculture farming. The results suggest that while PPF
could be made to work, its economic viability is difficult to gauge.
Proponents do not maintain that PPF should replace all annual
monoculture farming, but they do believe it would make economic sense
on marginal lands with highly erodible soils, a situation that exists
in many areas of the world, including much of the United States.

The Road Ahead

A natural prairie may have more than 200 plant species and several
times that number of microscopic soil animals working in concert. To
reengineer such an environment for the purpose of yielding specific
crops would be a great challenge. But perhaps an even greater
challenge is making sure that the necessary intellectual and
experimental work takes place. Most agricultural research is conducted
by large agricultural businesses that are not likely to see
significant economic promise in PPF. There is, however, an opportunity
to continue research on PPF in developing countries, where the
development community is paying increasing attention to agriculture as
a key to reducing poverty.

While the current focus is mainly on improving industrial agriculture
— in Africa in particular, institutional, social, and technological
advances work in favor of including PPF as a means of improving
agriculture and reducing poverty. In the institutional arena, the
creation of the Comprehensive Africa Agriculture Development Programme
provides a mechanism for funding agricultural research that may open
the door for studies on perennial polycultures. In the social realm,
along with the increased attention to poverty reduction that has
fueled interest in agriculture, a growing emphasis on sustainability
also makes PPF look attractive. Finally, two technological
developments provide impetus for research into perennial polycultures.
The first is the increased ability of biotechnology to modify
characteristics of plants. The second, which affects Africa
specifically, is the cataloging of neglected native crops to identify
those that might be more successful than species in common use — a
line of inquiry that could be an invaluable asset in the search for
species appropriate to PPF. In short, there are elements in place that
could help make PPF a reality. Only lacking are greater recognition of
the role that perennials could play and the will to include them in
the future of agriculture.

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