Dry soils and mixed predictions for expected rainfall could make planting green tricky this year.
Much of Pennsylvania has received below average rainfall over the past 60 days. While above average rainfall is predicted for the second week of May, the days should be dry until then.
Penn State Extension agronomist Heidi Reed tells us that planting green, or planting into a living cover crop, continues to grow in popularity for many reasons, including soil moisture management, soil conservation and weed suppression. There are also some reports of slug suppression.
However, it is crucial to consider current soil moisture conditions and expected rainfall if you are planning to plant green.
Our research shows that planting green significantly dries the top 3 inches in the soil profile, compared to planting into cover crops that are killed a week or more prior. This is because the growing cover crop transpires and draws water out of the root zone. A drier seedbed can be a great benefit in a wet spring, but it can be detrimental for the main crop in a dry spring. On the other hand, the increased mulch cover after planting green conserves soil moisture in summer.
Whether to terminate the cover crop now or wait and then plant green is a judgment call every farmer has to make. As a guideline, if current soil moisture conditions are dry, which seems to be the case in a fairly large portion of the state, and there is little rainfall in the forecast, it is wise to terminate the cover crop now and plant when the cover crop mulch is dry and crisp.
If, however, you do decide to plant green this year, know and understand these best management practices.
Soybeans are more adaptable to planting green than corn. Get comfortable with soybeans first. Equipment must be well maintained and calibrated. Roll cover crops over 18 inches tall and use aggressive row cleaners to help warm soil in the furrow. Planters work better than drills for soybean establishment through thick cover, due to better seed placement. Check if you are planting deep enough. You must account for the residue thickness.
Use an extra 50 pounds per acre of nitrogen at corn planting to compensate for nitrogen tie-up by a cereal cover crop, with the remainder of nitrogen needs applied at side-dress based on yield goals.
PSNT (pre-sidedress nitrate test) and tissue sampling can help dial in nitrogen needs. Scout for early season pests and use IPM to manage pests. Minimize neonicotinoid seed treatments and preemptive insecticide sprays that can kill predators of insect and slug pests.
Consult with farmers in your area who have planted green successfully.