|A major portion of
the experimental farm is devoted to a study of mustard
MOSCOW, Idaho, posted August 2, 2005: A University
of Idaho student club – Soil Stewards – is cultivating
both a new crop of produce for sale and an understanding of organic
agriculture at a UI experimental farm east of Moscow.
The students are working alongside UI soil scientists in the College
of Agricultural and Life Sciences, who are exploring the nature
of sustainability in organic farming at the soil level and the potential
of mustard meal in achieving that goal.
This marks the third growing season for the club, which includes
about two dozen members from a wide range of majors – from
theater to business. “Some members are more interested in
learning how to grow food, while others are more interested in research,”
said Jodi Johnson-Maynard, professor of soil science.
The research has resulted in numerous small independent projects
carried out by students through directed studies. The plots also
have been used for one senior’s project and are currently
the field site for a student in the McNair fellowship program.
|University of Idaho
student club Soil Stewards has succeeded in getting fresh
organic lettuce into their dining halls mainly by growing
it themselves. The produce is also sold to Washington
The club is selling shares in its community supported agriculture
program, or CSA. Subscribers pay the fee up front, assuming some
of the risk that goes with farming, and receive in turn weekly supplies
of fresh, organic produce.
Last summer, the club sold 10 CSA shares. This year it expects
to produce enough to support 25 shares. The 10-week subscription
The club also sells produce from a stand on campus and delivers
produce such as salad greens and basil to Sodexho, which manages
campus dining services. Johnson-Maynard said prospects are good
for expanding that relationship.
The proceeds from the produce paid for the use of three acres and
an elaborate irrigation system installed at the Department of Plant,
Soil and Entomological Sciences experimental farm.
Much of the club’s area is planted to organic spring wheat
to grind into flour, with another half an acre of vegetables. Much
of the garden is devoted to variety trials, testing which kinds
of tomatoes, potatoes, eggplant and other vegetables grow best under
organic systems on the Palouse.
Another major portion of the plot is devoted to a study of mustard
meal as a soil amendment for organic farming.
“Mustard is a natural fit for us because of the work other
UI researchers have done, ranging from plant breeding to biodiesel
development,” Johnson-Maynard said.
The oils pressed from mustard, Canola and rapeseed can either be
used in diesel engines straight or converted to biodiesel, a use
that is attracting greater interest with rising fuel prices.
The meal left over after the oil is pressed has attractions of
its own, Johnson-Maynard said. The cornflake-like meal contains
more nitrogen than most animal manures, one of the most common organic
An elaborate irrigation system
was installed at the farm to minimize water use.
That’s where the other research on the farm reaches into
the realm of high science. Experiments funded by a $613,000 USDA
National Research Initiative grant focus on intriguing questions,
such as why mustard meal appears to release more nitrogen for plant
use into the soil than the meal alone contains.
The NRI team is tracking the path of nitrogen through the soil.
One promising result so far, Johnson-Maynard said, is that the most
common form of nitrogen found after the meal is applied is ammonium,
which is less mobile than nitrates and less likely to contaminate
As for why more nitrogen appears to be freed up for plants, another
valuable property of mustard and its kin appears to be in play,
Glucosinolates are chemicals that give mustard its zip. They also
form new compounds that can kill weeds or soil microbes, benefits
that farmers of all persuasions are learning to value.
The researchers suspect that the “extra” nitrogen may
come from microbes killed by the mustard meal.
Exploring the benefits of mustard meal could help organic farmers
find new ways to fertilize and protect their crops, aiding their
survival, and their sustainability, in the long run, Johnson-Maynard