Mapping Flood-Prone Soybean Fields
By Don Comis
January 24, 2000
Two days of wet feet can be enough to cost soybean farmers a
quarter of their crop, depending on variety, soil type and growth stage.
To help develop more flood tolerant varieties,
Agricultural Research Service plant
physiologist Tara T. VanToai is using a robotic camera system to mass
screen soybean seedlings for flood tolerance. The system uses cameras to
record seedlings reactions to nutrient solutions through which air
containing 30 percent carbon dioxide is bubbled.
VanToai has found that too much CO2 in flooded soils causes yield losses, so
the seedlings reaction to high CO2 is a key indicator of flood tolerance.
To determine the relative roles of variety type and other farm conditions on
the flooding losses, VanToai and colleagues carried a Global Positioning System
receiver in a backpack across flooded soybean fields in Ohio. They mapped six
fields on private farms.
VanToai is with the ARS Soil Drainage Research Unit
in Columbus, Ohio. She did the mapping with colleagues at
The Ohio State University at Columbus
and USDAs Natural Resources
Conservation Service as well as farmers.
Scientists are using the mapping data to develop a statistical model to
identify the factors that most affect soybean yields in flooded fields.
NRCS would use the model for tailor-made advice to farmers on ways to
minimize flood losses, such as which soil types are particularly vulnerable to
flooding. It would be especially important for farmers to plant only the most
flood-tolerant varieties on those soils.
ARS is the chief scientific agency in the U.S. Department of Agriculture.
Scientific contact: Tara T. VanToai, ARS
Soil Drainage Research
Unit, Columbus, Ohio, phone (614) 292-9806, fax: (614) 292-9448,