ATTRA is the national sustainable agriculture information service operated by the USDA. It is headquartered in Fayetteville, Arkansas with offices in Montana and California. The document discusses principles of sustainable weed management for crop lands, including using allelopathic cover crops like rye that release chemicals to inhibit weed growth. It also discusses using crop rotations, intercropping, and weed-free cropping designs to manage weeds proactively by addressing their root causes rather than reactively controlling them with tillage and herbicides. The focus is on managing croplands according to nature's principles to reduce weed problems over the long run.