|
11-13-07
ORGANIC PRACTICES OUTPACE CONVENTIONAL IN LONG-TERM RESEARCH
AMES, Iowa -- After nine years of comparison, the clear differences between
organic and conventional crop production systems are emerging: the longer
rotations and careful management of the organic system show greater yields,
increased profitability, and steadily improved soil quality over conventional
practices.
Those are the conclusions drawn from experimental plots set up at the Iowa State
University Neely-Kinyon Research Farm near Greenfield. The plots are part of the
Long-Term Agro-ecological Research (LTAR) initiative led by Kathleen Delate of
the ISU agronomy and horticulture departments and supported by the Leopold
Center for Sustainable Agriculture since 1997. The study is believed to be the
largest randomized, replicated comparison of organic and conventional crops in
the nation.
Delate is now finishing her tenth year of organic production at the farm, and
has nine years of comparative data from the combined crop trials.
"We set up the experiment in 1998 to examine suitable crop rotations that would
provide high yields, grain quality and adequate soil fertility during the
three-year transition to organic and following certification," she explained.
"We replicated conventional and organic systems, using identical crop varieties,
and found that organic crop yields were equal to conventional acres in the three
years of transition. In the fourth year, organic corn yields in the longest
rotation outpaced those of conventional corn. Organic and conventional soybean
yields have been similar every year of the trial."
But the biggest differences are in soil and water quality. Delate said the
organic plots infiltrate more water, which reduces soil runoff and more
effectively recharges groundwater supplies. The organic soils also cycle
nutrients more efficiently, making them available when and where the plants need
them. Soil structural stability also remained good, despite increased tillage
involved with the organic rotations.
Delate will discuss her research at the 7th Annual Iowa Organic Conference
November 19 in Ames. The conference also includes sessions on organic livestock
production, weed management, direct marketing and opportunities for selling
organic crops, and ways of producing fruit and vegetable crops in an organic
system.
Registration is now open at
http://www.ucs.iastate.edu/mnet/organic07/home.html. For more information
about the ISU Organic Agriculture program, go to:
http://extension.agron.iastate.edu/organicag/ or call (515) 294-5116.
Through its research and education programs in the areas of policy, marketing
and ecology, the Leopold Center supports development of profitable farming
systems that conserve natural resources. The Center was established by the 1987
Iowa Groundwater Protection Act.
For more information,
contact:
|
