"Sustainable agriculture" is a term loaded with positive meaning, like "organic farming" and "health food." The University of Minnesota Agricultural Experiment Station is expanding its sustainable agriculture research, especially on a unique site at the Southwest Experiment Station, Lamberton.

Sustainable agriculture is a term claimed by many philosophies of farming. For the University, Kent Crookston, experiment station agronomist and director of the university working group on sustainable agriculture, says it represents approaches and techniques ranging from totally organic to modified safe chemical use. The goal is agriculture that will be acceptable now and into the future, allowing long-term profitability.

Crookston notes that anything not profitable for farmers in the long term will not be accepted, and farming practices that can't sustain the farming environment will, by definition, eventually put the farmer out of business.

Experiment station researchers and outside consultants representing organizations involved in sustainable agriculture have been working on a preliminary model to direct research on the "Koch farm" being leased by the University. The consultants include representatives from the land Stewardship Project, which helps farmers change to a more diversified agriculture sys:em; the Rodale Research Center, a leading national advocj'te for organic farming; and Winrock International, sponsor of international agricultural projects in nine countries.

Crookston says there is wide national interest about the Koch farm property. Nowhere else in the nation is there as large a property with such nearly natural levels of soil nutrients, and as convenient a location for research.

The Koch farm is directly across the road from the well established Minnesota Agricultural Experiment Station at Lamberton. It has had very few chemical inputs over the past quarter century. For instance, phosphorous levels closely approximate what's found on patches of native prairie, Crookston says. It's a unique opportunity to pursue agricultural questions in natural, unenhanced soil.

The Koch farm has other unique aspects as a research site. There is no drainage tiling, and it has never been deeply tilled. The near natural levels of phosphorous and potassium are not duplicated at any experiment station in the nation.

With the operational framework for Koch farm research now laid out, detailed planning has begun. Staggered crop rotations are likely so every crop will be available for study in any given year, Crookston says. Some of the acreage will also be held for future experiment opportunities.

Richard Harwood, of Winrock International, Arkansas, said there is a need to recognize agriculture as being a biologically structured system. "We obviously need to know more about nutrient flow and nutrient and chemical interactions," he said. We need to recognize that there's often a greater availability of nutrients than soil tests indicate, and we need to study much more closely the rotation effect of cool season and warm season crops as an approach to biological weed control, he said.

-Larry A. EtkinThis weed infestation at the Southern Experiment Station, Waseca, is part of a series of experiments testing biological controls. Rye, the tan stand, is being tested because it inhibits weed seed germination.