Location: Agroecosystems Management ResearchTitle: Cover crop rotation effects on growth and development, seedling disease, and yield of corn and soybean
|ACHARYA, JYOTSNA - Iowa State University
|KASPAR, THOMAS - Former ARS Employee
|LENSSEN, ANDREW - Iowa State University
|ROBERTSON, ALISON - Iowa State University
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/25/2019
Publication Date: 3/1/2020
Citation: Acharya, J., Moorman, T.B., Kaspar, T.C., Lenssen, A.W., Robertson, A.E. 2020. Cover crop rotation effects on growth and development, seedling disease, and yield of corn and soybean. Plant Disease. 104(3):677-687. https://doi.org/10.1094/PDIS-09-19-1904-RE.
Interpretive Summary: Rye cover crops overwinter and reduce nitrate leaching in the spring, improve soil health, and provide protection against erosion. Rye shares the fungal pathogen, Pythium, with corn and killed rye cover crops increase corn root disease and reduce yield in some years. This field research compared rye or camelina cover crops preceding corn or soybean over three years in the field. Clade B Pythium species were predominantly detected by qPCR in corn seedlings, while Pythium Clade F species were predominantly detected in soybean seedlings. Rye preceding corn caused more disease and reduced corn yield but these effects were not found with camelina. Soybean was not affected by either cover crop. This research informs farmers and other agriculturalists of a promising alternative cover crop to rye in the upper Midwest.
Technical Abstract: A three-year research trial was established to study the effect of two cover crops, winter cereal rye (Secale cereal L.) and winter camelina [Camelina sativa (L.) Crantz] used either in all three years or in rotation with each other, on corn (Zea mays L.) and soybean [Glycine max. (L.) Merr.] growth and development, root disease and yield in 2016, 2017, and 2018. Results showed, in general, corn growth and development was better following a cover crop of camelina and had reduced root disease, a lower Pythium population in seedling roots and greater yields compared to corn planted after a cover crop of rye. Alternately, both camelina and rye cover crops before soybean had either a positive or no effect on soybean growth and development, root disease and yield. In 2017 and 2018, Clade B Pythium species were predominantly detected by qPCR in corn seedlings, while Pythium Clade F species were predominantly detected in soybean seedlings. Moreover, Pythium Clade B populations were greater in corn seedlings planted after a rye cover crop compared to those planted after a camelina cover crop, while Clade F populations were greater on soybean seedlings planted after a camelina cover crop compared with those planted after a rye cover crop. This study demonstrated that a winter camelina cover crop grown before corn had less negative effects on corn seedling growth, root disease, and final yield than a winter rye cover crop before corn. Additionally, neither cover crop had negative effects on soybean and the cover crop in the preceding spring had no measurable effects on either corn or soybean.