By Blake Jackson
Maximizing cover crop biomass before planting soybeans can be challenging for farmers who want to balance this with the desire to plant as early as possible within the recommended window.
Delaying planting reduces soybean yield potential because it shortens the growth phase, but allowing cover crops to grow longer can potentially enhance yields by providing benefits to the soil.
A study was conducted to explore the compromise between soybean planting time and cover crop termination timing. The research focused on how soil moisture and availability influence the decision.
Field experiments took place in Landisville and Rock Springs, Pennsylvania, over two years (2022 and 2023). The cover crop used was cereal rye in 2022 and triticale in 2023.
The study tested four treatments:
- Early Planting Brown – Soybeans were planted early, with the cover crop terminated two weeks before planting.
- Early Planting Green – Soybeans were planted early, with the cover crop terminated at planting.
- Late Planting Brown – Soybeans were planted late, with the cover crop terminated two weeks before planting.
- Late Planting Green – Soybeans were planted late, with the cover crop terminated at planting.
Results showed that when soybeans were planted early, yields were higher in two out of three trials when cover crops were terminated at planting ("planting green") rather than beforehand.
Planting green maintained better soil moisture, which helped reduce drought stress and supported soybean growth during critical stages like pod formation.
However, planting green can reduce soil moisture before planting, potentially delaying soybean emergence, especially in dry conditions.
In 2023, planting green during a dry spring delayed soybean emergence by about a month. Thus, planting green is most beneficial in wet conditions or low-lying fields where excess moisture may be a concern.
For completed study visit, https://extension.psu.edu/the-dilemma-between-maximizing-cover-crop-biomass-and-planting-soybeans-early
Photo Credit: istock-urpspoteko
Categories: Pennsylvania, Crops, Soybeans