- Agronomic: corn, rye, soybeans
- Crop Production: cover crops, intercropping
In the mid-Atlantic region, the inclusion of double-crop soybean in wheat-soybean-corn rotations limits legume cover crop adoption due to the shortened window for establishing cover crops after the soybean harvest. Double-crop soybeans are harvested in mid-November; however, legumes must be seeded by late September to early October in this region to ensure establishment and high biomass production. To improve legume cover crop performance and subsequent adoption, we will evaluate a novel cover crop interseeder technology, which allows growers to drill cover crops into a standing soybean crop. This practice could transform growers’ ability to integrate legume cover crops into a grain rotation and offset inorganic nitrogen fertilizer needs in the corn phase. However, it would require transition from a narrow-row soybean spacing (7.5 - 15 in) to a wide-row spacing (30 in) since current interseeder options are designed for 30 in crop row spacings. Specific objectives of this study include: 1) quantify the effect of row spacing (15 in vs. 30 in) on double-crop soybean yield; 2) evaluate the effect of interseeded cover crops on wide-row double-crop soybean yield and harvestability; 3) determine the legume species which, in combination with cereal rye in wide-row double-crop soybeans, produces the largest amount of cover crop biomass; and 4) quantify nitrogen contribution of cover crop mixtures to corn yield.
Project objectives from proposal:
The specific objectives of this research are to:
(1) Quantify the effect of row spacing (15 in vs. 30 in) on double-crop soybean yield. Hypothesis: there will be no significant yield difference between double-crop soybeans planted in 15 in rows vs. 30 in rows.
(2) Evaluate the effect of interseeded cereal rye-legume cover crop mixtures on wide-row double-crop soybean yield. Hypothesis: there will be no difference in yield between wide-row (30 in) soybean grown with and without interseeded cover crops.
(3) Determine the legume species which, in combination with cereal rye in wide-row double-crop soybeans, produces the largest amount of cover crop biomass. Hypothesis: the cereal rye-hairy vetch cover crop treatment will produce the highest levels of biomass of the five cover crop treatments.
(4) Quantify nitrogen contribution of cover crop mixtures to corn yield. Hypothesis: corn yields will be the highest for corn planted in the cereal rye-hairy vetch treatment plots.