New tool for organic farming: the cover crop mat

Organic farmers have to make tough choices between controlling weeds and protecting soil from erosion. For example, large-scale organic farming relies heavily on tillage. Tillage breaks up the soil to kill weeds and prepare it for planting. However, heavy tillage can compact the soil, cause erosion, and deplete nutrients. As a result, some organic farmers are turning to cover crops to control weeds.

Cover crops are planted after harvest as a catch crop, improving the soil with living roots that protect it from erosion and add nutrients. Cover crops are usually plowed, but another option is to flatten them to form a thick mat or carpet. This is done with a press roller, which is a heavy, rolling drum attached to a tractor.

The farmer then uses a no-till planter to plant seeds in the flattened mat for the next season. The new crop grows through the cover crop residue, helping to suppress weeds.

This method, called organic rotational no-till based on cover crops, allows farmers to skip spring tilling and weeding. By simply flattening a cover crop, farmers don't have to disturb the soil for a new crop. The flattened cover crop suppresses weeds and retains soil moisture.

All the new trials bring complications. For example, if you flatten it too late, the cover crop can produce seeds. The result is a weedy cover crop that competes with next season's cash crop. And if you flatten it too early, it can grow back.

It all depends on the timing. Usually, letting the cover crop grow longer produces the best, if not perfect, results. Without this new tool, farmers have to plow the field multiple times, rake it, plant it and do a lot of weeding. Cover crop eliminates a lot of labor time and saves valuable diesel fuel. Despite the challenging timing, flattening cover crops to form a mat has a lot of potential.