UK Research Breaking Down Production Barriers
PRINCETON, KY.
Access to water is the biggest limiting factor
to Kentucky soybean and corn yields. Researchers
in the University of Kentucky
College of Agriculture, Food and Environment
are hoping they can help increase yields by
breaking down a hard layer in the soil called the
fragipan.
The fragipan is formed by a naturally occurring
chemical process that creates a cement-like
layer in the soil. About 50 million acres in the
United States and 2.7 million acres in Kentucky
have a fragipan layer in the soil. In Kentucky,
this layer is found in silty loess soil types usually
between 20 and 24 inches below the soil
surface. While it can be found throughout the
state, it particularly affects soils and crop production
in the Purchase and Green River areas.
“In the summertime, it reduces the amount of
water available to a crop, causing corn and soybeans
to yield 20 to 25 percent less,” said Lloyd
Murdock, UK soil scientist and the project’s
principal investigator. “In wheat, the fragipan
causes water to build up in the winter and early
spring, so it affects root growth and final productivity
too.”
With funding from the Kentucky Soybean Promotion
Board, Kentucky Corn Growers Association
and Kentucky Small Grain Growers
Association, Murdock and fellow UK soil scientists
Tasios Karathanasis, Chris Matocha and
John Grove hope they can find a relatively accessible
and inexpensive material that can
break up the fragipan. They expect this product
will be something producers can apply to the
soil surface to penetrate the soil or a plant they
can use in rotation with grain crops.
“Our objective is to remediate the pan and increase
yields by at least 10 percent,” Murdock
said. “Over a 10-year period at today’s grain
prices, a 10 percent yield increase could translate
into an additional $1,400 to $1,500 per acre
for producers and have a $2 billion impact on
Kentucky’s agricultural economy.”
Karathanasis and Matocha began conducting
lab research in January to see if they can find a
material that will break down fragipan samples
taken from the soil at the UK Research and Education
Center in Princeton. Materials they are
currently studying include calcium carbonate,
fly ash, municipal waste and poultry litter.
These materials were mixed with water to emulate
rainfall. In addition to visually observing the
fragipan samples breaking down, the researchers
will analyze the solution for inorganic
and organic ions, pH level and released chemical
binding agents. This will give them to clues
to the chemical process that must occur for the
fragipan to dissolve. Research will continue on
these materials for the next several months,
Karathanasis said.
As Karathanasis and Matocha identify potential
materials, Murdock and Grove will conduct
field studies on them. They have already begun
studying the extent that different depths of the
fragipan affect yields. They are also looking at
certain promising materials and plants.
“There are some early indications that poultry
litter, annual ryegrass, magnesium and sodium
will disperse the pan,” Murdock said. “Increasing
soil pH will also disperse the pan. Some organic
compounds also seem to do so, but we
don’t know what those are yet.”
The researchers hope to positively identify materials
capable of breaking up the fragipan
within five years. Δ
Fragipan, a cement-like layer found in some Kentucky soils, is
limiting the yield potential of the state’s row crops.
PHOTO: Katie Pratt, UK Ag Communications