Oilseed Cash Cover Crops Enhancing Productivity and Profit in Corn-Soybean Rotations.

Incorporation of cover crops into the corn and soybean rotation is necessary to address many of the ecological consequences of the rotation. However, integration of cover crops into the corn and soybean rotation, as well as subsequent broad adoption, has been thwarted because of the difficulty of establishment, cost of seed, and lack of direct economic return. The winter annual oilseed cropping systems offer growers both ecological and economic opportunities, by providing living cover to protect the soil, and producing a marketable seed product from the oilseed crop. The goal of this research was to investigate the productivity and profitability of adding cash cover crops to a corn and soybean rotation, as well as quantify the weed suppressive ability of these cash cover crops. Preliminary results show that winter annual oilseed systems increase total seed yields (i.e. oilseed + soybean yield) up to 25% when compared to a mono-cropped soybean. In addition to yield benefits, the results also show the ability of the oilseeds to suppress weeds. It has been found that 97% weed biomass suppression occurs in pennycress (Thlaspi arvense L.) systems, and 85% in rotations including camelina (Camelina sativa [L.] Crantz). The over-yielding potential of this cash cover crop system, along with its weed suppressive ability, could result in additional productivity and profitability for growers.