Background and aims: Prairie restoration aims to create self-sustaining, resilient prairies that ameliorate biodiversity loss and soil deterioration associated with conversion of native grasslands to agriculture. Legumes are a key component of the nitrogen-limited prairie ecosystem. Evidence suggests that lack of suitable rhizobia may explain legume absence from restored prairies. This study explores effects of novel alternative inoculant delivery methods on: (a) prairie legume establishment, (b) soil biological properties, and (c) inoculant strain ability to nodulate the host over time. Methods: Alternative inoculation methods for seven legume species were tested in a replicated field experiment. Legume establishment, microbial biomass carbon and nitrogen, and rhizobial inoculant strain recovery were measured over a 3-year period. Results: Legume species richness in the second growing season was enhanced by a soil-applied granular clay inoculant, while seed-applied powdered peat inoculation was generally ineffective. When Dalea rhizobia were recovered 3-year after planting, only 2 % from the seed-applied inoculation treatment identified with the inoculant strains, whereas this amount ranged from 53 to 100 % in the other inoculation treatments. Some legumes established unexpectedly effective symbioses with strains not originally intended for them. Conclusions: Results provide new insights on inoculation of native legumes, especially when a mix of seeds is involved and the restoration targets harsh environments.
Bibliographical noteFunding Information:
Acknowledgments This research was made possible by the financial support of the Minnesota Department of Transportation (MNDOT) Grant MN/RC 2008–48, to which we express our gratitude. Peter Graham was a key contributor to this study, now published in honor to his memory. The first author thanks the generous technical assistance of Becki Tlusty, a major help for several years. The thorough and helpful review by Heather Reynolds is also acknowledged, as are helpful comments by three anonymous reviewers. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Copyright 2014 Elsevier B.V., All rights reserved.
- Prairie legumes