|WILLIAMS, MARY - Michigan Technological University|
|DUMROESE, KASTEN - Us Forest Service (FS)|
|PAGE-DUMROESE, DEBORAH - Us Forest Service (FS)|
Submitted to: Journal of Arid Environments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/22/2015
Publication Date: 2/1/2016
Citation: Williams, M.I., Dumroese, K.R., Page-Dumroese, D., Hardegree, S.P. 2016. Can biochar be used as a seed coating to improve native plant germination and growth in arid conditions? Journal of Arid Environments. 125:8-15.
Interpretive Summary: Biochar is a popular agronomic tool for improving soil properties and has the potential to improve native plant establishment and growth on disturbed arid and semi-arid lands. Te evaluate biochar as a restoration tool, we analyzed the effect of biochar seed coatings on the germination and growth of four plant species native to western North America. Non-coated and biochar-coated seeds of mountain brome (Bromus marginatus Nees ex Steud), prairie junegrass (Koeleria cristata [Ledeb.] Schult.), Wyeth's buckwheat (Eriogonum heracleoides Nutt.), and western yarrow (Achilliea millefolium L.) were germinated and grown in laboratory and field settings. We evaluated germination, growth, and biomass of each species. Across different temperature and water potential treatments in the lab and in the field, biochar coating had either a neutral or negative effect on germination and growth for all species. Seed coatings can enhance seed germination and early growth, but our results show few benefits of biochar as a seed coating treatment on germination and growth of four native plant species. However, given that this study is one of the few to evaluate biochar as a seed coating, our findings encourage further study across a range of seed types, and climatic and soil conditions.
Technical Abstract: Millions of hectares of arid and semi-arid rangelands throughout the world have been disturbed by fire and invasive weeds and are relatively difficult to restore using traditional seeding approaches. Biochar is an organic charcoal product that has been used extensively as a soil amendment to improve plant growth. Most previous studies of biochar effects on seed germination and seedling establishment have been confined to agricultural or tropical plants, and primarily looked at biochar addition to the soil. In our study, we evaluated biochar effects on establishment of 4 native restoration species to determine whether use of biochar as a seed coating would have a positive effect on seedling establishment for rangeland restoration applications. Our biochar applications delayed germination and reduced germination capacity in the laboratory, but had little or no effect on plant growth in the field under conditions of low water stress. Additional studies should be done to determine whether biochar may improve establishment of rangeland species under more stressful conditions of drought or nutrient limitations.