Influence of sediment flushing from dam on growth of rice
2006
Hori, M.(Mitsubishi Research Inst. Inc., Tokyo (Japan)) | ; Tanonaka, A. | ; Wakabayashi, H. | ; Kojima, T.
The past sediment flushing from Dashidaira dam at Kurobe river caused serious problem on the fishery of the area. In the present study, we evaluated the effects of the flushing on the agriculture by the field experiment using test plots. The actual sediment sample was used for the evaluation. The growth rate of rice plants and rice yield were measured in the test paddy rice plots, with and without sediment distribution to evaluate the effects on the growth at their rooting and boot stage respectively. The test were conducted in May and August for the first year but only in August for the second year. The other experimental management conditions such as water, agricultural chemicals, fertilizers and so on are set the same as the surrounding rice pads. In the first year, the distribution at their rooting stage reduced plant height, however, did not show any clear different yield from the results of the plots without distribution. The distribution at the boot stage did not cause any effect on plant height, stem number or yield. The second year experimental results showed that the lower concentration of the suspended matter than 10,000 mg/l does not cause any effects on the growth, yield and quality, or soil quality.
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