Crop yield in the USA is frequently limited by a lack of pollinators

Authors: REILLY, JAMES - Rutgers University; ARTZ, DEREK - Former ARS Employee; BIDDINGER, DAVID - Pennsylvania State University; BOBIWASH, KYLE - Simon Fraser University; Boyle, Natalie; BRITTAIN, CLAIRE - University Of California, Davis; BROKAW, JULIA - University Of Minnesota; CAMPBELL, JOSH - University Of Florida; DANIELS, JARET - University Of Florida; ELLE, ELIZABETH - Simon Fraser University; ELLIS, JAMIE - University Of Florida; FLEISCHER, SHELBY - Pennsylvania State University; GIBBS, JASON - University Of Manitoba; GILLESPIE, ROBERT - Wenatchee Valley College; GUNDERSEN, KNUTE - Michigan State University; GUT, LARRY - Michigan State University; HOFFMAN, GEORGE - Oregon State University; JOSHI, NEELENDRA - University Of Arkansas; LUNDIN, OLA - Swedish University Of Agricultural Sciences; MASON, KEITH - Michigan State University; MCGRADY, CARLEY - North Carolina Museum Of Natural Sciences; PETERSON, STEPHEN - Foothill Bee Ranch; Pitts Singer, Theresa; RAO, SUJAYA - University Of Minnesota; ROTHWELL, NIKKI - Michigan State University; WARD, LOGAN - Michigan State University; WILLIAMS, NEAL - University Of California, Davis; WILSON, JULIA - Michigan State University; ISAACS, RUFUS - Michigan State University; WINFREE, RACHEL - Rutgers University

Submitted to: Proceedings of the Royal Society B
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/7/2020
Publication Date: 7/29/2020
Citation: Reilly, J., Artz, D., Biddinger, D., Bobiwash, K., Boyle, N.K., Brittain, C., Brokaw, J., Campbell, J., Daniels, J., Elle, E., Ellis, J., Fleischer, S., Gibbs, J., Gillespie, R., Gundersen, K., Gut, L., Hoffman, G., Joshi, N., Lundin, O., Mason, K., Mcgrady, C., Peterson, S., Pitts Singer, T., Rao, S., Rothwell, N., Ward, L., Williams, N., Wilson, J., Isaacs, R., Winfree, R. 2020. Crop yield in the USA is frequently limited by a lack of pollinators. Proceedings of the Royal Society B. 287(1931). https://doi.org/10.1098/rspb.2020.0922.
DOI: https://doi.org/10.1098/rspb.2020.0922

Interpretive Summary: Most of the world’s crops depend on pollinators, so declines in both managed and wild pollinators raise concerns about food security. However, the degree to which pollination is actually limiting current crop production is poorly understood. We established a nation-wide study to measure the extent of pollination limitation in seven crops at 131 locations situated across major crop-producing areas of the USA. In each location, we measured the how often bee visited flowers and the resulting crop yield. We looked at these relationships to determine whether yields were less than possible because of a lack of pollinators. We found that five out of seven crops showed evidence of lack of pollination. Managed honey bees were responsible for slightly more pollination than wild bees, but wild bees provided comparable (or sometimes higher) amounts of pollen in most crops. This was found even though we worked in heavily managed and expanse agricultural regions where habitat for wild pollinators can be lacking. We estimated the nation-wide economic value of wild pollinators to the seven crops we studied, which are a small subset of all pollinator-dependent crops grown in the U.S., at over $1.5 billion. Our study underscores the need for continued research into the relative roles of honey bees and wild bees in the major global production areas of all important crops, and the need to monitor the relationship between local pollinator populations and crop yields as environmental and agricultural production conditions change.

Technical Abstract: Most of the world’s crops depend on pollinators, so declines in both managed and wild pollinators raise concerns about food security. However, the degree to which pollination is actually limiting current crop production is poorly understood. We established a nation-wide study to measure the extent of pollination limitation in seven crops at 131 locations situated across major crop-producing areas of the USA. In each location, we measured the frequency of bee visits to flowers and the resulting crop yield and used the shapes of these relationships to determine whether yields were limited by a lack of pollinators. With this proxy we found that five out of seven crops showed evidence of pollination limitation. Managed honey bees were responsible for slightly more pollination on average than wild bees, but wild bees provided comparable (or sometimes higher) amounts of pollen in most crops. This was found even though we worked in agriculturally-intensive regions where habitat for wild pollinators can be lacking. We estimated the nation-wide economic value of wild pollinators to the seven crops we studied, which are a small subset of all pollinator-dependent crops grown in the USA, at over $1.5 billion. Our study underscores the need for continued research into the relative roles of honey bees and wild bees in the major global production areas of all important crops, and the need to monitor the relationship between local pollinator populations and crop yields as environmental and agricultural production conditions change.