 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Vetiver Grass for the Remediation of Soil Contaminated with Heavy Metals) ผู้เขียน: ดร.นวลฉวี รุ่งธนเกียรติ, ศาสตราจารย์ ,  Prapai Chairoj สื่อสิ่งพิมพ์:pdf AbstractThree vetiver grass ecotypes, Kamphaeng Phet, Ratchaburi and Surat Thani were planted in soil supplemented with different amounts of manganese (Mn), zinc (Zn), copper (Cu), cadmium (Cd) and lead (Pb). It was found that these heavy metals did not affect the growth of the vetiver grass, even though the uptake amount increased as the applied amount increased. Ratchaburi ecotype gave the highest shoot dry weight and lowest root weight and at the same time had significantly higher Mn, Zn and Cd amounts in shoots than Surat Thani and Kamphaeng Phet ecotypes. However, Ratchaburi and Kamphaeng Phet ecotypes showed similar copper uptake. The root of Ratchaburi ecotype could also absorb significantly higher amounts of Zn, Cd and Pb than those of Surat Thani and Kamphaeng Phet ecotypes. For Mn and Cu, Ratchaburi and Surat Thani ecotypes could uptake more than those of Kamphaeng Phet. As expected, the residual heavy metal in soil increased as the applied amount increased. The soil planted with Ratchaburi vetiver ecotype had less residual heavy metals than that planted with the other two ecotypes since it absorbed more heavy metals. Therefore, this specific ecotype would be useful for remedying soil contaminated with heavy metals. |
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หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Uptake Potential of Some Heavy Metals by Vetiver Grass) ผู้เขียน:ดร.นวลฉวี รุ่งธนเกียรติ, ศาสตราจารย์, Prapai Chairoj สื่อสิ่งพิมพ์:pdf AbstractThe uptake potential of upland vetiver grass (Vetiveria nemoralis) ecotype Kamphaeng Phet and lowland vetiver grass (Vetiveria zizanioides) ecotypes Ratchaburi and Surat Thani, for different heavy metals was evaluated. Varying amounts of manganese (Mn), zinc (Zn), copper (Cu) cadmium (Cd) and lead (Pb) were applied to one-month old vetiver grass planted in pots. Vetiver grass plants were harvested at 60 and 120 days after the heavy metal application and the concentrations of the heavy metals in shoot and root parts were determined using atomic absorption spectrophotometry. The results indicated that at the concentrations tested, the heavy metals applied had no significant effect on growth of all vetiver grass ecotypes. Vetiver grass harvested at 120 days yielded more shoot dry matter than those harvested at 60 days. The Ratchaburi ecotype demonstrated significantly increased in root mass at the 120-day harvest. No obvious increase for Kamphaeng Phet and Surat Thani and no significant difference in root between these ecotypes mass were observed. For the three vetiver grass ecotypes tested, the uptake of heavy metals was proportional to the concentration of the applied heavy metals. The Ratchaburi ecotype had the highest concentration of the heavy metals in shoots, except at the 120-day harvest, Pb concentration was significantly lower than that of the Kamphaeng Phet ecotype. The concentration of heavy metals in vetiver grass shoots harvested at 120 days was lower than that of the 60-day harvest due to dilution effects. However, heavy metal concentration in roots was increased from 60- to 120- day harvest. This may be due to the spatial limitations of the pot or the restricted translocation of heavy metals from roots to shoots which resulted in an accumulation of the heavy metals in the roots. Therefore, when utilizing vetiver grass for the phytoremediation of heavy metal contaminated soil, the above ground biomass should be regularly cut to stimulate regrowth and the translocation of heavy metals to shoots. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Fertility Improvement of Sandy Soil by Vetiver Grass Mulching and Compost) ผู้เขียน:ดร.นวลฉวี รุ่งธนเกียรติ, ศาสตราจารย์, Prapai Chairoj, Sunthorn Chookhao สื่อสิ่งพิมพ์:pdf AbstractTo improve the productivity and fertility of Hupkapong sandy soil, fresh vetiver grass was used in mulching and vetiver grass compost was applied in combination with chemical fertilizer. Soil fertility and productivity were evaluated from the yields of Insee 1 super sweet corn hybrid grown on the soil, and soil moisture determined using a neutron probe. The results indicated that super sweet corn hybrid gave a maximum growth and yield when it was fertilized with 75-75-75 kg N-P2O5-K2O ha-1 in combination with soil mulching of 31.25 t ha-1 of fresh vetiver grass. Reducing the application of N-chemical fertilizer and vetiver mulching by 50% resulted in a decrease in super sweet corn hybrid yields. This decrease, however, was not statistically significant. Mulching was found to conserve topsoil moisture and increase plant growth and production. Soil incubated with vetiver grass or its compost released approximately the same amount of available-N. However, fresh vetiver grass mineralized higher levels of available-P and extractable-K than vetiver grass compost. One ton of vetiver grass yielded 1.32 kg t-1, 0.24 kg t-1 and 6.73 kg t-1 of available-N, available-P and extractable-K, respectively. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Decomposition of Vetiver Shoot and Effect of Vetiver Mulching on
Super Sweet Corn Hybrid Yield) ผู้เขียน:Prapai Chairoj, ดร.นวลฉวี รุ่งธนเกียรติ, ศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractTwo experiments were conducted on Hupkapong Soil Series. In the first experiment, the
decomposition of vetiver shoot, and the nutrients released during the process were measured. The second
experiment investigated the mulching effect of vetiver shoot on yield of super sweet corn hybrid in the
wet and dry seasons. The results from the decomposition study indicated that, within 90 days, more than
80% of the buried vetiver shoot decomposed but less than 30% of the same material left on soil surface
disintegrated. It was also found that one ton of dry vetiver shoot buried at the depth of 10 cm would yield
mineral nitrogen, available phosphorus, and extractable potassium up to 4.4, 2.2 and 20.5 kg while that
left on soil surface would yield only 0.85, 0.74 and 7.20 kg, respectively. In the second experiment, the
application of 31.25 t/ha fresh weight of vetiver shoot for mulching in addition to a half rate (35.5-35.5-
35.5 kg of N-P2O5-K2O/ha) of the recommended fertilization produced the same yield of super sweet corn
hybrid as applying the full rate of the recommended fertilizer alone. Mulching the soil with vetiver shoot,
therefore, could reduce 50% of chemical fertilizer needed for the super sweet corn hybrid production. |