Click image for caption and other photo information.

Fewer Chemicals May Give You Fewer Weeds

Weeds can grow on large farms as well as in tiny backyard gardens. These pests compete with desired plants for food, sunlight and water. For many, it seems that applying chemicals to the soil is the only way to make sure weeds do not grow.

According to microbiologist Robert Kremer, of the Agricultural Research Service's Cropping Systems and Water Quality Research Unit in Columbia, Mo., certain organic practices can help increase numbers of beneficial microorganisms in soil, making it "weed suppressive" so that less herbicide could be used on the crops.

Many of these practices are easy enough for gardeners to perform on their small gardens and can also be effective on large farms. Examples include adding compost, manure or organic mulch to the soil. Farmers can also grow a cover crop in the winter or consider ways to improve crop residue management. In addition, farms without livestock may want to add some animals since they produce and can distribute organic material that helps soil.

According to Kremer, weed-suppressive soils can develop in most regions and should not be greatly affected by climate or topography. Researchers have developed these soils in places such as the Pacific Northwest, as well as in Texas.

Kremer is developing easier soil tests for detecting the presence of the weed-suppressing microorganisms.

ARS is the U.S. Department of Agriculture's chief scientific research agency.