Farm Manager Scott Latham describes some of the reasons he grows cover crops at Sauvie Island Organics, a 24-acre vegetable farm that serves the Portland, Ore., market. The farm's soils are sandy, so cover crops are used to maintain or improve soil organic matter amidst fairly intensive vegetable production.
A notable benefit of this focus on soil organic matter has been a reduced demand for irrigation. He has cut irrigation intervals from every five to seven days, down to every seven to nine days. In turn, this has helped with management of some foliar diseases. In addition, cover crops help with nutrient management: Latham follows a broccoli crop with a sudangrass cover crop, which captures excess nitrogen in the soil.
Cover crop mixes he commonly includes in his rotations are cereal rye and common vetch, triticale and Austrian winter peas, and winter wheat and Austrian winter peas.