Space Science and
Engineering Center. "In three to five years, this technology
will be available to farmers through their dealers." Molling
described the research at the 2002 Wisconsin Fertilizer, Aglime &
Pest Management Conference in Madison.
Agricultural modeling systems analyze data about weather,
landscape, crops and management techniques to produce maps that
predict soil water content, grain moisture and the effects of
compaction on yield. Farmers can use these maps to help them make
decisions about how much fertilizer to spread, for example.
"Agricultural models are most important in helping to make
management decisions," Molling says. "Yield is a measure of the
success or failure of those decisions."
Molling, along with John Norman, Cristine Morgan and Birl Lowery
of the College of Agricultural and Life Scienceís soil science
department, wanted to determine how much data are necessary to
create models that would give the farmer accurate and useful
information. The most costly and time-consuming data involve
charting the characteristics of the land, so they studied how
effective different levels of data were in predicting the actual
yield of a test field.
For the first level of information, the researchers used data
from a USDA soil survey and a USGS topographic map. For the second
level, they added information about past yield, and used global
positioning system devices to map the elevation of the field. For
the third level, they used specialized equipment to get information
about the soil, including the thickness and locations of the soil
horizons and how much water it could hold.
"We found two different levels of information that will be useful
to farmers," said Molling. "The first is using yield data to get the
water-holding capacity of the soil and combining that with a
topographic survey. This is inexpensive, because most of the data
already exists, and itís a good introduction to using modeling."
The second level of information is more expensive, but it
provides a higher level of information, according to Molling. "A
farmer would hire someone with the proper equipment to analyze the
structural characteristics of the soil and survey the field with a
global positioning system. Itís more expensive, but it will give the
farmer useful information ó especially for land that he or she has
not farmed before."
The modeling system tracks the movement of water across and
through the soil, and lets a farmer see how changing management
techniques, such as no-till versus chisel plow, affects fertilizer
runoff. "Chances are that farmers can reduce their costs by using
only as much fertilizer as the crop needs," Molling says. "And there
are more and more regulations about fertilizer use, controlling
runoff and spreading manure."
Molling knows of at least one company in Wisconsin that is trying
to build enough equipment and knowledge to offer this new service to
farmers, and she predicts other companies will follow suit. "As
farmers learn about these techniques, they start to ask around for
dealers," she says. "When the dealers hear about the demand, they
then become interested in offering the service."
The researchers would now like to partner with a company to
create easy-to-use, point-and-click software. "Entering the data
into the system is the biggest problem right now, so we want to work
on making it more user-friendly," Molling explains.