Computer Modeling Can Contribute to Thai Soybean
By Ann Perry
October 26, 2009
Agricultural Research Service (ARS)
scientists are testing the soybean model GLYCIM to improve its performance
under a range of conditions around the world. In the process, theyve been
able to pinpoint the best agronomic practices for maximizing soybean production
GLYCIM was designed to simulate the growth of any soybean cultivar on any
soil at any location and for any time of year. ARS research leader
Reddy and soil scientist
Timlin at the
Crop Systems and Global Change Laboratory in Beltsville, Md., partnered
with scientists S. B. Lokhande and V.M. Salokhe, who work at the
Asian Institute of Technology in
Pathumthani, Thailand, to see how well GLYCIM estimated soybean yield potential
The team programmed GLYCIM with data from a field study conducted in
Thailand that tracked soybean growth and yield. Then they introduced new
dataincluding four years of weather measurements, seven planting dates,
three soil types and three soybean cultivarsand developed 504 cultivation
and yield scenarios for two key soybean production areas in northern Thailand.
The scientists already knew that high temperature stress could reduce
soybean yields, and this study indicated that losses at the two Thai locations
could be as high as 40 percent. GLYCIM results also indicated that it is
critical for farmers to use optimal planting dates to achieve high yields at
these sites. Planting on May 2 and May 16 produced the greatest yields, while
earlier planting resulted in yield losses ranging from 7 percent to 17 percent.
Yield losses in delayed planting simulations averaged around 30 percent.
These results further support GLYCIMs use as a comprehensive
mechanistic model for predicting soybean growth, development and yield across a
range of agricultural systems. For instance, the model can help Thai farmers
identify the best dates and soybean cultivars to obtain the highest yields,
which could help increase production to meet current and future demand. Farmers
in Thailand and other tropical regions could also use GLYCIM to estimate how
different management practices could be adjusted to deal with the effects of
global climate change and changing weather patterns.
This research supports the U.S. Department of
Agriculture priorities of responding to climate change and promoting
international food security.
ARS is USDAs principal intramural scientific research agency.