By Sharon Omahen

University of Georgia

With a computer program, scientists across the globe can now
plant, tend and
harvest “crops” in just minutes.

The software is called Decision Support System for
Agrotechnology Transfer,
or DSSAT. It was created by a team of researchers from the
universities of Georgia,
Florida, Hawaii, Guelph and Iowa State and the International
Center for Soil
Fertility and Agricultural Development.

DSSAT is a computer model that allows the user to simulate a
crop’s growth,
yield, water and nutrient requirements and the impact of the
environment.

The program didn’t develop overnight. In fact, the software’s
fourth version
will be released in early 2003. About 40 researchers and
graduate students from
across the globe met on the UGA experiment station campus in
Griffin, Ga., Dec.
9-18 to see the newest DSSAT software.

“Our goal this week was to introduce the newest Windows-based
version of DSSAT
and make sure the users understand and can use our system,”
said Gerrit Hoogenboom,
a DSSAT developer and an agricultural engineer with the UGA
College of Agricultural
and Environmental Sciences. “We definitely don’t want it to be
on shelves collecting
dust when it should be put to use.”

Don’t conduct all research on
computer

Hoogenboom told the first DSSAT Version 4 users not to rely
solely on the software
for their research data.

“The results you obtain from the software are not ultimate
truths, and they’re
not meant to replace real experiments, real data or critical
thinking,” he said.
“Anytime you run a model you should question the results.”

Though not a substitute for the real thing, the computer model
can have great
value to researchers.

“The trial-and-error approach is expensive,” said Jim Jones,
a
DSSAT developer
and a UF agricultural engineer. “With DSSAT, we can couple the
systems approach
with experiments. As P.G. Cox said, agricultural science is
not
a science unless
it predicts and then tests its predictions.”

The DSSAT software allows the user to simulate the growth of
peanuts, sunflowers,
sugarcane, wheat, soybeans, rice, tomatoes, sorghum, millet,
barley, potatoes,
corn, cowpeas and dry beans. Cotton will soon be added to the
list.

“Those who use DSSAT now are sharing their work and their data
via a computer
listserv,” Jones said. “In this way, the software is
contributing to the whole
scientific community.”

Helping farmers identify and solve
problems

The crop-simulation information will be shared with
farmers.

“Our goal is to educate the people who talk to farmers
directly,” said Ken
Boote, a DSSAT developer and UF agronomist. “Consultants, ag
industry representatives
and extension agents have the potential to spread the word to
farmers. It’s
a technical type of transfer, so only farmers with interest in
this technology
would benefit from actually using the software themselves.”

Boote says the way the software presents the data is an
essential part of the
success of DSSAT.

“You can’t give numbers that no one can understand,” he said.
“Our program calculates
crop growth and development in a mathematical sense and then
shows it visually
and graphically.”

DSSAT has also been used as an effective tool after a crop has
been harvested
to identify the source of production management problems.

“It’s a way to see the whole picture and what is limiting the
crop,” Boote said.
“The software actually works better this way.”

Software applications unlimited

In the early stages, the DSSAT developers tested the software
using four years
of real-crop data from Florida peanut farms.

DSSAT has been used on food security projects in Africa and
other developing
countries, too, and to study the impact climate change has on
food production,
he said.

“It’s been used in Arkansas to help with early-season soybean
plantings, in
Kentucky for determining planting dates, in Georgia for
predicting agricultural
water usage and in Africa to diagnose yield loss of peanut
crops from disease,”
Boote said. “The list of applications is never-ending.”