Agri News, MN
06-20-07
ISU researchers use satellite to track rust
Iowa State University researchers have developed a way to use satellite
images to find Asian soybean rust.
"What we did on the ground 10 to 15 years ago, we can do now with satellites,''
said Forrest Nutter, professor of plant pathology.
Using remote sensing, the global positioning system and geographical
information system technologies, scientists can measure the green leaf area of
soybeans to detect and identify diseases down to the area of a square meter,
about 1.2-square yards.
"Plant pathogens and pests impact the green leaf area index of crop canopies in
different ways and those changes can be detected and quantified using remote
sensing, Nutter said.
Carbon receives plenty of attention
Carbon, especially carbon dioxide, has received a lot of attention from
policymakers and the press. What is carbon and how does crop management
affect it,'' asks Jodi DeJong Hughes, crops educator with the University of
Minnesota Extension Service.
Carbon doesn't exist alone, she said. It's usually attached to other elements,
such as oxygen or hydrogen. When carbon is in the atmosphere, it is in the
carbon dioxide form. Plants can photosynthesize carbon dioxide for sugar
formation and other plant processes.
As this happens, the carbon is transported to plant roots, stems, leaves and
grain. For food crops such as corn, wheat and soybeans, a small percentage of
the carbon is leaked out into the soil via roots, said DeJong Hughes. Some
carbon is removed by harvesting the grain, and the remainder exists in the roots
and crop residue.
Pre-sidedress soil nitrate test is useful
The pre-sidedress soil nitrate test is a tool that Wisconsin corn growers can use
to improve the efficiency of nitrogen fertilizer applications, says Tim Jergenson,
Barron County ag agent.
The PSNT is most useful for confirming legume and manure nitrogen credits and
providing a site-specific estimate of soil nitrogen availability. The test is
particularly important when a corn grower is unsure about the amount of manure
that had been previously applied or when the stand density of a previous alfalfa
crop is unknown, Jergenson said.
Another situation where the PSNT is of particular value is when abnormal
weather conditions occur that may impact nitrogen mineralization rates such as
cool weather or excessive rainfall, he said.
Keep neighbors in mind this summer
Livestock producers need to keep neighbors in mind while implementing best
management practices to grow their farms successfully and responsibly.
These activities take on added significance during summer when neighbors are
more involved in outdoor activities and weather conditions hinder timely odor
dispersion, says an expert with the Coalition to Support Iowa's Farmers.
"Prevailing summer winds typically originate from the south-southeast, so you
must be especially considerate of the people and places located to the north and
northwest of your farms," said CSIF organizational director Rex Hoppes