Appreciating those insights only leads to the deeper and more
important question: How did indigenous cultures, without all the
shiny tools of modern science, develop such sophisticated knowledge of nature? What is their science like?
The Assumptions of Modern Science
The milpa system contrasts sharply with the image of growing only
a single crop in any given field. Vast “amber waves of grain,” as
the song says (Figure 3). Why? Note that “modern” agricultural
practices neatly align with typical “modern” research methods.
One limits the number of variables. Ideally to just one. Mixed crops
only seem able to confuse the process. This approach to doing science thus implicitly promotes single-crop farming (DeWalt, 1994).
Perhaps even without a recognition that an assumption is at work.
Second, in seeking to control variables and test each, one by
one, modern science favors a stable and consistent background.
Visualize a greenhouse with carefully regulated growing conditions and a standardized genetic strain. There is no theoretical reason why such conditions should foster better farming. But they do
facilitate experimental manipulations and comparisons. Coincidentally, such relatively uniform conditions were found historically in the temperate United States: in the large expanses of
flat, fertile land, especially across the prairies of the Midwest
and the Atlantic coastal plains. The ultimate outcome has been
large-scale farms where one can easily manage uniformity. Large
scale, in turn, promotes mechanization (at least where fuel is
available cheaply). The economics of capital-intensive agriculture,
in turn, shift power from individual farmers to large industries.
Major consequences from a “simple” assumption. At the same
time, genetic homogeneity becomes another crop management
ideal. Controlled sameness. However, this raises vulnerability to
disease and insect herbivores. More problems. Indigenous alternatives help highlight the often unnoticed assumptions about what
some may see as just “ordinary” farming, here related to the
research goal of controlling variables.
A third assumption involves soil and environmental contexts.
Again, “modern” research seeks to reduce variables. So, an agronomist
will tend to regard a bare field, isolated from its surroundings, devoid
of vegetation – an agricultural “tabula rasa” – as an appropriate baseline. Thus, scientists will focus on controlling and measuring each soil
nutrient individually. They thereby promote the corresponding
notion of artificial fertilizers to manage soil. Tillage practice will target
leaving bare ground. But this will accelerate soil erosion. Long-term
soil conservation becomes an afterthought. Meanwhile, when one
focuses on crop yield alone, one can easily overlook the runoff of
excess fertilizers. That’s not part of the system under study. When
eutrophic marine dead zones appeared worldwide, where major rivers
dump fertilizer runoff into the ocean, many scientists were surprised.
But in retrospect it seems wholly predictable. Again, simple assumptions about science can have unexpected but profound consequences.
Of course, farming using this set of “modern” research assumptions has been remarkably successful. By one measure, at least. Output per acre has increased dramatically. Yields are up. Labor costs
are down. U.S. agricultural productivity more than doubled in the
second half of the twentieth century. Impressive, indeed! But this
goal as a standard of “effective” farming is itself a feature of context.
It ranks productivity, or volume of yield, above all other values. As
scientists have learned in the past few decades, those high returns
depend, sadly, on immense energy inputs. In fact, modern “
scientific” farming is not very efficient at all when one compares food
energy (output) with the agricultural labor and energy inputs.
Today, more energy is used in producing industrially farmed
food than is available nutritionally in the food itself. For similar
reasons, Jared Diamond (1987) famously called farming “the
worst mistake in the history of the human race.” Now, we also
see other consequences: global warming from the use of carbon
fuels and environmental degradation from excess chemical pesticides and fertilizers. Modern agriculture’s achievements come at
an often unacknowledged cost. Attitudes about sustainability are
surely evolving, but the key question may be: Why did the science lead us here and seem to justify it?
Figure 2. The Amazon’s annual floodwaters have receded,
and farmers have planted in the new beach of loose soil. Soon
this will be a lush farm of manioc and squash.
Figure 3. Monoculture, the core assumption of modern
farming, reflecting ideal research conditions. (Photo: Pixabay)