PROBLEM SOLVING...

Weed management is often the greatest challenge to organic crop production, especially for field crops and vegetables.  Weeds occur naturally, especially when agricultural soil is left uncovered or the crop is a poor competitor.  Building soil fertility using a good humus-building rotation is one of the first steps to effective weed management.  A diverse rotation also reduces the number of niches problem weeds can exploit from year to year.

Many difficult-to-control weeds are also indicators that the soil has nutritional or physical problems, and nature is trying to restore health and balance.  Avoiding field operations that can damage soil structure is one preventative; careful fertilization is another.

Mechanical controls are commonly relied upon for routine control of weeds, including cultivation, mowing, mulching, and flaming.  However, there is a big discussion surrounding the tillage of the soil.  Most organic farmers continue to use such practices, but there are a few who are interested in reducing these activities in order to conserve organic matter, reduce erosion, and save on expenses. 

Allowed practices and materials typically include but are not limited to the following:

Crop rotation

Grazing

Smother crops- fast growing cover crops, like buckwheat

Nurse crops- companion crops that are sown with other crops to suppress weeds during establishment years.

Weeder geese

Interseeding

Sanitation- for example, removing weedy stolons and rhizomes from cultivating  equipment and cleaning combines of stray weed seed between fields

Competitive crop types and varieties

Higher crop seeding rates

Altered planting schedules

Natural (non synthetic) mulches

Mowing

Cultivation- clean cultivation should NOT be done where or when it will cause significant soil erosion

Hand weeding or hoeing

Solarization- uses clear plastic to trap the sun’s energy and heat to a high temp.  In addition, this also help with plant diseases and insect pests.

Flooding

Flaming and other natural forms of thermal weed control

Natural herbicides- for example, vinegar-based (acetic acid) products and myco-herbicides

Plastic mulch

Esoteric practices                                                    

Prohibited materials typically include but are not limited to the following:

            Most synthetic herbicides

            Heavy metal herbicides

            Soap based herbicides- these may only be used in non crop areas of the organic farm

            Micronutrient-based herbicides

Since mulching with non porous plastic can increase the hazard of soil erosion, appropriate measures must be taken; mulching with plastics must NOT be allowed to cause erosion.  Plastic mulches should not be allowed to photo degrade or deteriorate t\in the field. They should not be incorporated into the soil.  Plastic wastes should be disposed of in a manner that does not cause pollution or crop contamination. 

Another issue that many organic farmers face is insect pests and diseases.  Though these pests can be very harmful, pests and diseases play a vital role in natural selection by removing sick and unthrifty plants.  Organic producers maintain that organic soil-building