Soybean Yield by Distance in Fields with Supplemental Honeybee Pollination

William Passifiume
Undergraduate (Entomology)
Dr. Reed Johnson

Soybeans are a self-pollinating crop, however, pollination services have been shown to increase their yield in previous field and cage experiments conducted in the southeastern US and Brazil. More information is needed on both pollination benefits to soybeans grown in Ohio, and an understanding of the effects of distance from bee colonies on soybean pollination has not been addressed. Two soybean fields near Wooster, OH and two soybean fields near London, OH were supplanted with two small, nucleus honeybee colonies placed in the center of the fields prior to bloom. Just prior to harvest, plants from 5m from the colony, the midpoint, and 5m from the edge were collected to assess the effect of distance on their yield. The plants' height, base diameter, nodes, pods, and seeds were measured and counted for each plant. Total pods per node was the primary metric used to assess yield. The yield in total pods per node significantly varied across distances surrounding honeybee colonies in two of the four fields. Larger fields saw the most significant difference with yield by distance. Whether yield was highest near the honeybee colony or near the edge was not consistent across all fields. Soybean yield does benefit from pollination services, and the distance from the colony has an effect on the yield in larger fields. Plants closer to the colony saw higher yields than those further away, excluding plants collected from field edges. Patterns in the yield at various distances suggest that other factors may be affecting yield at the edges of fields. Control for field size, soybean variety, and comparison to fields without bees should take place in further studies.