Managing weeds is a never ending battle for all farmers, but particularly for organic farmers who cannot and do not want to use herbicides. Growers must weigh weed benefits such as breaking up compaction and adding organic matter to the soil, to weed downfalls such as weed pressure affecting yield and stealing nutrients from the cash crop.
There are several organic methods that have been used to manage weeds with success, such as cultivation, no till or low till with cover crops that are mowed or rolled, and black plastic. Cultivation can be very effective; however this is labor intensive, fuel intensive and can lead to problems with compaction and soil carbon loss years down the road. Black plastic is widely used to suppress weeds and it does a great job of smothering weeds where it lies; however it has other drawbacks such as its expense and the amount of waste produced.
Cover crops have been a major weed management focus at Rodale Institute for more than three decades. Cover crops suppress weeds and also act as a green manure (providing nutrients like nitrogen back into the soil), increasing organic matter and sequestering soil carbon, and reducing erosion to improve soil health. Our continued research aims to help growers understanding when weeds transition from an aid to a problem, and how to manage them through the growing season.
Learn more about our work on no- and low-till techniques without the chemicals by visiting Organic No-till.