UC Davis soil scientists and irrigation experts are teaming up on a sustainable agriculture project that looks at the water-cleansing effects of cover crops -- plants grown to reduce weeds and improve or protect the soil, rather than being harvested.

The university's Sustainable Agriculture Farming Systems project is using the Davis campus's Russell Ranch as the main site for the examination into what happens when cover crops are planted and the resulting debris is left in the furrows.

"Slowing irrigation water down in the furrows increases the water soil penetration and reduces the amount of runoff that enters streams and rivers," said Will Horwath, one of the project's lead researchers and a professor of soil biogeochemistry in the UC Davis Department of Land, Air and Water Resources.

"It's one of the farming practices that has been identified as a sustainable way to prevent nutrients and chemicals from the fields from entering drinking water supplies, and for recharging groundwater supplies," he said.

Some California farmers, however, have been hesitant to adopt reduced tillage and cover-crop practices because of the cover-crop residue that is left behind in the field. Horwath hopes this study will help answer many of their questions.

The research protocol includes data collection from Yolo and Stanislaus county farms, and input from growers and UC Cooperative Extension farm advisers.