AMES, Iowa – At the edge of a corn field on a clear but windy June day, microbiologist Tom Moorman lifts a metal lid and reveals a collection of bottles, tubes, meters and cables in a shallow pit. The system is designed to capture runoff from 24 plots. Moorman and his research group then analyze the nutrients in the water from each container to measure runoff levels. They are comparing different cover crops. “We have two basic ones that we’re looking at here,” he said, standing among the rows, “rye cover crops, which we’ve looked at for quite some time. But this particular treatment, instead of rye, we’re trying to grow winter camelina.” Camelina is an oilseed that can be planted in the fall and harvested in the summer, even as soybeans are growing in nearby rows. Moorman, who works for the Agricultural Research Service of the U.S. Department of Agriculture in Ames, Iowa, has been looking at whether the camelina cover crop reduces nutrient runoff. He measures nitrate, phosphorus…