Document Type : Research Paper
Authors
1
Department of soil science engineering, Collage of Agriculture and Natural Resources,, University of Tehran, Karaj, Iran
2
Department of Soil Science, College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran.
3
Department of Environmental Engineering, Faculty of Environment, University of Tehran, Tehran, Iran.
Abstract
Periphytons in aquatic ecosystems has the ability to absorb/release significant amount of nutrients. This study examines the effect of epiplon and epiphyton on changes in pH, EC and soluble potassium, periodically. This experiment was conducted as a factorial in a completely randomized design with three factors: 1- periphyton at 22 levels (9 samples of epipelon, 9 samples of epiphyton, 3 fallow soil samples and control), 2- mineral at 2 levels (muscovite and phlogopite), 3- sampling time at 4 levels (0, 7, 14 and 21).
Both types of periphyton showed high potential in releasing potassium from silicate minerals. Throughout the 21-day experiment, all treatments had significant statistical differences compared to the control (without periphyton/soil but whit minerals). Overall, the highest dissolution rate from both minerals were observed in the epiphyton treatments. Potassium dissolution increased in all treatments until 7th day and then relatively decreased in most treatments by day 14, which was attributed to increased biomass in medium. The highest soluble potassium on 21th day was 14.33 mg L-1, which shoes a 3.6-fold increase compared to the control. The lowest soluble potassium levels were observed in treatments inoculated with fallow soil. Solubilization rate of phlogopite was higher than that of muscovite, but in most treatments, the difference was not statistically significant. Overall, pH and EC results showed increasing (indicating increased photosynthetic activity) and decreasing (indicating increased biomass and higher absorption of soluble materials) trends, respectively.
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