In Cuba, cleaner rivers
follow greener
farming
When the Soviet Union
collapsed in the early 1990's, food production on the island of Cuba was
disrupted—as the supply of Russian fertilizers, pesticides, tractors, and oil
dried up. Under the stress of an imminent food crisis, the island quickly
rebuilt a new form of diversified farming—including many urban organic
gardens—that depended less on imported synthetic chemicals. Over the last two
decades, Cuba blossomed into a world-class showcase of conservation
agriculture, with improved soils and cleaner water.
At least that's been a
popular story among journalists.
Now—for the first time
in more than fifty years—a team of Cuban and U.S. field scientists have worked
together to rigorously test a key aspect of this story: the impacts of
contemporary agriculture on water quality in Cuba's rivers. Despite centuries
of sugarcane plantations and other intensive farming, the international team
discovered that none of the rivers they explored show deep damage.
Instead, the
scientists measured much lower nutrient concentrations in all the twenty-five
Cuban rivers they studied than are found in the U.S.'s Mississippi River. And
they think Cuba's transition toward sustainable agriculture—and
its reduced use of fertilizers on cropland—may be a primary cause.
"A lot of stories
about the value of Cuba's shift to conservation agriculture have been based on
fuzzy, feel-good evidence," say University of Vermont geologist Paul
Bierman, who co-led the new research, "this study provides hard data that
a crucial part of this story is true."
Bierman and
geoscientist Amanda Schmidt from Oberlin College led the American half of the
international team, while Rita Yvelice Sibello Hernández, a scientist with CEAC
(Centro de Estudios Ambientales de Cienfuegos), an ecological research group,
headed up the Cuban effort with CEAC science director Carlos Alonso-Hernández.
The new study,
"¡Cuba! River Water Chemistry Reveals Rapid Chemical Weathering, the Echo
of Uplift, and the Promise of More Sustainable Agriculture," was published
January 30, in the early online edition of the journal GSA Today,
the leading publication of the Geological Society of America.
Conversely, "Cuba
has been having a forced experiment in organic agriculture since the late
1980s," says Oberlin's Amanda Schmidt. "So Cuba is a very interesting
place to look at the effects of both conventional agriculture and the effects
of organic agriculture at a national scale,"—and may suggest pathways to
improve U.S. agriculture. Fertilizer use in Cuba peaked in 1978 and has been
lower since, according to World Bank and other data. U.S. fertilizer use spiked
after the 1960s and has remained at more than twice the Cuban use rate.
"There's a
takeaway we bring back to the U.S.: our river waters do not need to look the
way they do," says Paul Bierman—a professor in UVM's Geology Department,
Rubenstein School of Environment and Natural Resources, and Gund Institute for
Environment—"we can manage fertilizer differently." There are, of
course, complex questions about yields, farm policy and more, but this newly
reported data on the low levels of nutrient pollution found in twenty-five
Cuban rivers, "suggests the benefits of Cuba's shift to conservation
agriculture after 1990," the US/Cuban team writes, "and provides a
model for more sustainable agriculture worldwide."
