Out in the soybean fields, farmers and agronomists are debating a crucial question: what is the ideal spacing to maximize yields and optimize plant growth? Between the narrow row option, which boasts improved density, and wide rows which promote better airflow, the debate over row spacing in the soybean field offers plenty of food for thought.
In this blog, we take a closer look at the particularities of narrow rows vs. wide rows in soybean farming:
Narrow rows for increased density
- The quicker canopy closure offered by narrow rows supports optimal light interception. It improves the soybean plants’ photosynthesis production, while keeping sunlight from reaching the weeds.
- Narrow rows make the application of fungicides, insecticides or herbicides more difficult without putting tractor wheels on the row. Treatments must be applied pre-emergence, or early post-emergence to minimize damage.
- Narrow rows are more vulnerable to diseases, such as the soybean cyst nematode, brown stem rot or white mold. Essentially, this is due to the plants’ proximity to each other, which creates a moist environment conducive to the spread of disease.
Wide rows for improved airflow
- Wide rows are a good option in fertile soils that favour high growth rates. Bushy varieties thrive in these conditions and support quicker canopy closure.
- With good airflow and a dry environment, wide rows are preferable in fields that have a history of Sclerotinia. The phenomenon of lodging, which is closely associated with the disease’s development, is also rarely seen in wide rows.
- More space between plants means more opportunities for weeds to grow. Consequently, weed control becomes more crucial in wide-row crop systems.
- Yields are generally lower, especially in cold weather or late planting situations. In cool weather, plant development is often slower. The same is true in late planting situations, since seedlings have less time to develop and reach their full potential.
What the studies say
Research studies conducted in the U.S. show that < 15-inch rows outyield the > 30-inch rows. Indeed, in narrow rows, the plant canopy closes more than 15 days earlier than it does in wide rows. Light interception is also better, fostering higher growth rates. On average, narrow rows yield around 1 to 4 bushels/acre.
In summary, soybean plant spacings can vary due to a number of factors. Among these, the type of soil management system, equipment availability, weed management issues, soil conditions, the presence of Sclerotinia, as well as the planting date. The ideal choice often depends on considerations that are specific to each agricultural region.
Don’t hesitate to contact your Prograin representative if you have any questions!
Sources :
Vann, R. (2021). Sciences for Success : Row spacing [Vidéo]. YouTube. Science for Success: Row Spacing – YouTube
Conley, Shawn et al. (2020). How to pick the right soybean row spacing. Sciences for Success. https://soybeanresearchinfo.com/wp-content/uploads/2021/02/FINAL-2700-002-20-Row-Spacing_Science-for-Success-Dec-22_v1.pdf
Ministère de l’Agriculture, de l’Alimentation et des Affaires rurales. (2017). Guide agronomique des grandes cultures. Chapitre 2 : soya. https://www.ontario.ca/files/2022-10/omafra-agronomy-guide-for-field-crops-chapter-2-fr-2022-10-13.pdf
Licht, Mark. (2018). Consider 15-inch row spacing in soybean. IOWA State University of Science and Technology. https://crops.extension.iastate.edu/cropnews/2018/02/consider-15-inch-row-spacing-soybean Ouellet, Cindy. (2010). Le RAP. Fiche technique : grandes cultures, la pourriture à Sclérotes chez le soya. https://www.agrireseau.net/documents/Document_92969.pdf