Sign up for the
Weekly Harvest Newsletter!

Published every Wednesday, the Weekly Harvest e-newsletter is a free Web digest of sustainable agriculture news, resources, events and funding opportunities gleaned from the Internet. See past issues of the Weekly Harvest.
Sign up here

Sign up for the Weekly Harvest Newsletter

What Is Sustainable Agriculture?

Master Publication List

Search Our Databases

Urban Agriculture

Energy Alternatives

Beginning Farmer

Field Crops

Horticultural Crops

Livestock & Pasture

Local Food Systems

Food Safety

Marketing, Business & Risk Management

Organic Farming

Pest Management

Soils & Compost

Water Management

Ecological Fisheries and Ocean Farming

Other Resources

Sign Up for The Dirt E-News

Home Page

Contribute to NCAT


Newsletter sign up button

· Privacy Policy · Newsletter Archives

RSS Icon XML Feeds

RSS 2.0: Events, Breaking News, Funding Opportunities Atom: Events, Breaking News, Funding Opportunities


NCAT strives to make our information available to everyone who needs it. If you are a limited-access or low-income farmer and find that one of our publications is just not in your budget, please call 800-346-9140.


How are we doing?


Home  > Question of the Week

Question of the Week

Permalink Can crop rotation help manage weeds?

Answer: Yes! Crop rotations limit the buildup of weed populations and prevent major weed-species shifts. Weeds tend to prosper in crops that have requirements similar to their own. Fields of annual crops favor short-lived annual weeds, whereas maintaining land in perennial crops favors perennial weed species. In a crop rotation, the timing of cultivation, mowing, fertilization, herbicide application, and harvesting changes from year to year. Rotation thus changes the growing conditions from year to year—a situation to which few weed species easily adapt. Rotations that include clean-cultivated annual crops, tightly spaced grain crops, and mowed or grazed perennial sod crops create an unstable environment for weeds. Additional weed control may be obtained by including short-season, weed-smothering cover crops such as sorghum-sudan or buckwheat. Crop rotation has long been recognized for its ability to prevent weeds from developing to serious levels.

Incorporating crops with allelopathic effects into the rotation adds another element of control. Such crops include sunflowers, sorghum, and rapeseed. Allelopathic plants are those that inhibit or slow the growth of other nearby plants by releasing natural toxins, or "allelochemicals." Weed-control ability varies among varieties and management practices. For example, sweet potatoes have been shown to inhibit the growth of yellow nutsedge, velvetleaf, and pigweed. Field trials showed a 90% reduction of yellow nutsedge over two years following sweet potatoes.

Managing croplands according to nature’s principles will reduce weed problems on horticultural crops, or row crops, in small and medium-sized operations. Creativity is key to devising sustainable cropping systems that prevent weed problems. You can learn much more in the ATTRA publication Sustainable Weed Management for Small and Medium-Scale Farms. This publication discusses several strategies, both proactive and reactive, as alternatives to conventional tillage systems. Options include mulching, competition, crop rotations, and low-toxicity control alternatives. A resource list provides sources of further information.



: I want to raise sheep. What is the best breed to buy? »


No Comments for this post yet...

Question of the Week Archives