Paper presented at the 52nd CFCS Annual Meeting, Guadeloupe, July 10-16, 2016
Figure 3: Effect of Sargassum mulch height on soil respiration measured as SOLVITA Soil CO2 release at different times after treatment application. Mulch treatments were removed after 3 weeks (indicated by arrow).
Plant height over the 6-week period was significantly increased by the 8cm washed mulch treatment, however, no corresponding effect was observed for the unwashed Sargassum mulch treatment (Figure 4).
Figure 4: Effect of Sargassum mulch height and washing treatments on height of tomato plants averaged over a 6-week period. Conclusion Soil moisture content and biological activity were greatly enhanced by the use of Sargassum seaweed mulches. The large effect on soil respiration occurred under increased salinity conditions and continued even after the mulch was removed and soil moisture levels fell. Liquid extracts of seaweeds have been shown to promote germination and growth of tomato (Hernandez-Herrera et al. 2014). Data on plant growth suggest that the benefits of Sargassum seaweed mulches may be counteracted due to the direct effects of increased soil salinity on plants. Washing of the fresh Sargassum seaweed appeared to be of very limited benefit for reducing the soil salinization effect. Bibliografic references : Hernandez-Herrera, R., F. Santacruz-Ruvalcaba, M. A. Ruiz-Lopez, J. Norrie, and G. Hernandez-Carmona. 2014. “Effect of liquid seaweed extracts on growth of tomato seedlings (Solanum lycopersicum L.).” Journal of Applied Phycology 26 (1):619-628. doi: 10.1007/s10811-013-0078-4.
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