Mt. Pleasant studies what traditionally are known as the "three sisters": beans, corn and squash. These staples of Iroquois cropping are traditionally grown together on a single plot, mimicking natural systems in what agronomists call a polyculture. Though the Iroquois technique was not developed scientifically, Mt. Pleasant notes that it is "agronomically sound." The three sisters cropping system embodies all the things needed to make crops grow in the Northeast, she says.
She presented her work today (Feb. 15) at the annual meeting of the American Association for the Advancement of Science (AAAS) in Seattle. The talk, "Polycultural Cropping Systems From an Indigenous Perspective: Using Iroquois Worldview to Understand the Three Sisters," was part of a symposium on research methods in native science. This is the second year that such a symposium has been held at the AAAS.
Corn and beans are used throughout the Western Hemisphere, said Mt. Pleasant. "Both do better when they are grown together." Corn provides protection from weeds and insects and acts as a scaffold to support twining bean plants. The beans, in turn, produce nitrogen, essential for plant growth. Adding squash to the mix also controls the growth of weeds, and recycling crop residues (the "leftovers" of a harvest) back into the soil promotes fertility. A monoculture, in which only one crop variety is grown on a plot of land, is a relatively recent agricultural technique, noted Mt. Pleasant. Though it is suited to high-yield mechanized harvests, it leaves crops vulnerable to disease and insects. A polyculture reduces the risk of an entire harvest being wiped out in this way.
The role of the three sisters in the Iroquois diet is mirrored by the crops' place in Iroquois worldview and culture, where they are visualized as three siblings with very different personalities. Corn is austere, standing straight and tall; shy Beans clings to her legs; Squash is the "wild and impish" troublemaker. In the Iroquois creation story, they are the seeds that issue life on Earth, and they are woven into the laws that bind the Iroquois Confederacy. The three sisters are thanked for the sustenance they provide in the Thanksgiving Address recited at the beginning and end of ceremonial Iroquois meetings.
Indigenous culture holds broader lessons for our relationship with our environment as well, said Mt. Pleasant. Iroquois people have always recognized that they are part of an ecological system, she observed. "As we watch a lot of the ecological problems coming," like global warming and water contamination, "we recognize that we have a contract" with the Earth, "not domination" over it.
This realization, she said, has fueled an upsurge in interest in native science. "More and more young native people are ... questioning conventional science" as tribal colleges include native teachings in their curriculums, said Mt. Pleasant. She noted, however, that only a few non-Native American scientists attended last year's AAAS symposium on the subject.
As scientists begin to recognize the connections between systems they formerly studied in isolation, Mt. Pleasant hopes they will see what indigenous peoples have known all along: "We're all in this web, and when you pull on one part and it breaks, the whole web falls apart."
This release was prepared by Cornell News Service science writer intern Kate Becker.