Author
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Ries, Ronald |
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Submitted to: American Society for Surface Mining & Reclamation Annual Meeting Proceeding
Publication Type: Proceedings Publication Acceptance Date: 6/28/1999 Publication Date: N/A Citation: N/A Interpretive Summary: Predicting future grass stand success shortly after seeding makes possible prompt decisions on whether reseeding or other cultural improvement techniques are needed. A 3-year field study with 5 species and 11 seeding dates per year was conducted to evaluate grass development and success when grass was direct seeded into wheat stubble with a double disk cone seeder with depth bands and packer wheels. The number of grass seedlings m-2, the number of adventitious roots, Haun stage, leaf length, leaf area, and number of tillers were measured 45 days after emergence. Reasonable predictions of stand success were possible using the relationship of seedlings m-2 at 45 days after seeding with grass stems or plants m-2 at 2 years after seeding. However, multiple regression analysis for smooth bromegrass improved the R2 to 0.75 with the addition of adventitious roots, leaf area, and leaf length along with seedlings m-2. The R2 was increased to 0.58 for crested wheatgrass and improved to 0.38 for western wheatgrass with the addition of number of adventitious roots. The R2 for blue grama was increased to 0.65 with the addition of number of adventitious roots. These data show that the explanation of the number of stems or plants m-2 estimated 2 years into the future is improved by knowing something about the developmental stage of the seedlings m-2 at 45 days after emergence. Technical Abstract: Predicting future grass stand success shortly after seeding improves our understanding of the mechanism of seeding success and makes possible timely decisions on the potential productivity of new grass stands. A 3-year field study with 5 species and 11 seeding dates per year was conducted to evaluate grass development and success when grass was direct seeded into wheat stubble with a double disk cone seeder with depth bands and packer wheels. The number of grass seedlings m-2, the number of adventitious roots, Haun stage, leaf length, leaf area, and number of tillers were measured 45 days after emergence. Earlier results showed that grass stand success can be reasonably predicted from the relationship of seedlings m-2 at 45 days after emergence with grass stems or plants m-2 2 years after seeding. However, the simple coefficient of determination (r2) for these relationships was quite low. Further multiple regression analysis has shown that the R2 values can be significantly improved by adding the appropriate seedling growth stage to the number of seedlings m-2 at 45 days. For smooth bromegrass, the R2 was improved to 0.75 with the addition of adventitious roots, leaf area, and leaf length. The R2 was increased to 0.58 for crested wheatgrass and improved to 0.38 for western wheatgrass with the addition of number of adventitious roots. The R2 for blue grama was increased to 0.65 with the addition of number of adventitious roots. These data show that the explanation of the number of stems or plants m-2 estimated 2 years into the future is improved by knowing something about the developmental stage of the seedlings m-2 at 45 days after emergence. |
