IEEE Spectrum June, 2013 - 44

The age of plenty

farming, it is possible to have full food security," says Mohd Amin
Mohd Soom, the center's director.
Amin's approach to precision agriculture is what's often called
variable rate. It differs from the kind of tactics the Mitchells use
in that it does not assume every part of a field should be treated the same. Instead, farmers who practice this method take
into account variations in soil composition and plant growth to
determine exactly how much of something-water or fertilizer, say-
each tiny piece needs.
Amin has so far focused on fertility because he believes it can
make the biggest impact. Malaysian farmers typically apply chemical nutrients uniformly based on rates the government recommends, he says. His team has been trying to convince them they
can get higher yields and save costs if they can figure out which
areas should get more fertilizer and which ones should get less.
This isn't an easy calculation. Farmers first need to be able to
measure soil fertility quickly and cheaply, which means they can't
rely on laboratory tests. A simpler solution is to deploy electricalconductivity sensors. For more than a century, geologists have
used these sensors to chart Earth's interior and to sniff out oil
and gold. Around the mid-1990s, growers in the United States
and Europe began borrowing the technique to survey their soils.
The most popular mapping system came from a Kansas company called Veris Technologies. It consists of a wheeled frame,
which supports an array of platter-size steel disks. As a tractor
pulls the cart through a field, the disks penetrate the soil. One
pair of disks creates a voltage while a second pair measures how
much the current drops as it flows through the ground. By using
pairs of disks spaced at different intervals, farmers can gauge
conductivity at various depths. And by equipping the system
with satellite navigation, they can construct a detailed picture of
soil variability-including differences in texture, water-holding
capacity, and, to some extent, nutrient contents.
In 2004, Amin bought Malaysia's first Veris machine with money
from a government grant. The pilot study included only eight
farmers, whose paddies surrounded the coastal community
known as Tanjung Karang. Amin's team mapped the electrical
conductivity of the farmers' fields and took several hundred soil
samples over many seasons. Each season, the researchers used
the results to model the relationship between conductivity and
the amount of essential nutrients in the soil. Then they used the
model to create color-coded maps showing farmers how best to
distribute fertilizer. In some seasons, the model represented a
dependence that was statistically significant. In other seasons it
didn't, but they used it anyway. "It's not 100 percent accurate,"
admits Aimrun Wayayok, a soil expert at the research center.
This unreliability is why some farmers, including the Mitchells,
are skeptical of variable-rate methods. "Sprinkling a little bit less
phosphorus on one part of the field and a little more on another
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doesn't have a predictable benefit," Mitchell argues. "It's a very
small Band-Aid."
Aimrun disagrees. Electrical conductivity may not be the perfect predictor of soil fertility, he concedes, but it's a start. And
the maps have encouraged farmers to be more conscientious of
how much fertilizer they use. In some cases, Aimrun says, they
have cut their use by as much as 70 percent. "We are showing
them that reducing fertilizer doesn't necessarily reduce yield
and sometimes increases it," he says.
"Agriculture systems are very complex," says John Schueller,
an expert in precision farming at the University of Florida. "It is
impossible to optimize completely. Even in Iowa, where farmers have access to the best technologies, they're really not hitting absolute perfect conditions. So the question is: How close
can you get? Usually doing something is
better than doing nothing."
Today, about 30 farmers in Tanjung
Karang are enrolled in the center's precision program. And in the nine years since
the project began, the area has upped
production from 4 metric tons per hect30 metric tOnS
are (the national average) to more than
average yearly soil
6 metric tons per hectare.
loss per hectare
of farmland
It is arguable that a big driver of this
worldwide
success has been broadband access. In
2008, the center oversaw the construction of an Internet café in Tanjung Karang.
centimeter
Here,
Amin and his staff teach farmers in
preciSiOn
the community how to use computers and
level of accuracy
enabled by
browse the Web. They've also created a
state-of-thecustom
website where the farmers can
art navigation
access fertility maps for their fields and
technology
track their activities throughout the growing season.
On this February day, the café is quiet
and airy. Its picture windows frame undulating landscapes of tall
green rice grass. A few teenagers sit at terminals Facebooking and
playing video games. On a wall, someone has tacked a poster-size
copy of a check for 50 000 Malaysian ringgits (about US $16 000).
Printed on the bottom in Malay is the declaration "Best Paddy
Field Management, Selangor AgroFest 2011."
Eventually, a farmer named Aziz wanders into the café. He points
to the check. "He says he is proud," Ezrin translates. "He says previously, he protested precision farming. He could get 7 [metric] tons
per hectare, which is very good. But then he tried precision farming
and now he gets 9 tons-2 tons extra! And with half the fertilizer bags!"
Ezrin pauses. "See?" he says, grinning. "We are changing minds." n
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Table of Contents for the Digital Edition of IEEE Spectrum June, 2013