Organic produce, research take root on University of Idaho experimental farm

A major portion of the experimental farm is devoted to a study of mustard meal.

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 State University.

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 costs $150.

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 fertilizers.

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 groundwater.

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, Johnson-Maynard said.

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 said.