Madison, Wisconsin
April 14, 2008
Winter cover crops provide
important ecological functions that include nutrient cycling and
soil cover. Although cover crop benefits to agroecosystems are
well documented, cover crop use in agronomic farming systems
remains low. Winter cover crops are usually planted in the fall
after cash crop harvest and killed the following spring before
planting the next cash crop. Recent research has identified time
and money as major impediments to farmer adoption of winter
cover crops. Developing innovative cover crop management systems
could increase the use of winter cover crops.
A scientist with the USDA
Agricultural Research Service National Soil Tilth Lab and
colleagues at Iowa State University investigated the potential
for winter cereal cover crops to perpetuate themselves through
self-seeding, thereby eliminating the cost of planting a cover
crop each fall and time constraints between cash crop harvest
and the onset of winter. Results from the study were published
in the March-April 2008 issue of Agronomy Journal.
In the research investigation, winter rye, triticale, and wheat
were planted and managed chemically and mechanically in varying
configurations to facilitate self-seeding. After soybean harvest
in the fall of 2004 and 2005, establishment and green ground
cover of self-seeded winter cover crops was measured because of
their important relationships with nutrient uptake capacity and
soil erosion protection. The study revealed that plant
establishment through self-seeding was generally accomplished
within one week after soybean harvest. Green ground cover and
self-seeding was consistently higher with wheat.
“The significance of this research, in addition to lowering the
cost and risk of establishing cover crops, is to extend the
ecological functions that cover crops perform beyond the normal
cover crop termination dates between mid-April and early May,”
says Dr. Jeremy Singer of the National Soil Tilth Lab.
“Furthermore, producers using organic crop production techniques
could adopt these systems because of the potential for enhanced
weed suppression without soil disturbance.”
According to Singer, increasing the presence of cover crops on
the landscape can increase nutrient capture and lower soil
erosion, both of which can improve water quality.
Research is ongoing at the National Soil Tilth Lab to identify
self-seeded cover crop systems that minimize competition with
cash crops and maximize the effectiveness of self-propagation.
The impacts of cover crops on soil quality in systems with
biomass removal are also being investigated because cover crops
can help offset the carbon and nutrient losses that occur when
biomass is harvested in row crop production systems.
The full article is available for no charge for 30 days
following the date of this summary. View the abstract at
http://agron.scijournals.org/cgi/content/abstrasct/100/2/432.
Agronomy Journal is
a peer-reviewed, international journal of agronomy published six
times a year by the American Society of Agronomy.
The American Society of
Agronomy (ASA) is a scientific society helping its 8,000+
members advance the disciplines and practices of agronomy by
supporting professional growth and science policy initiatives,
and by providing quality, research-based publications and a
variety of member services. |
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