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Title:	The environmental fate of triclopyr and glufosinate ammonium in oil palm plantation soils
Authors:	Mohammed Abu Tayeb (P62937)
Supervisor:	Ismail Sahid, Prof. Dato' Dr.
Keywords:	Tasik Chini Soil Triclopyr
Issue Date:	30-Jan-2016
Description:	A study on the environmental fate of glufosinate ammonium and triclopyr, two commonly used herbicides in the Tasik Chini oil palm plantation was conducted in the state of Pahang, Malaysia. The composite soil samples from each experimental plot were collected at the following depths: 0-10, 10-20, 20-30, 30-40, 40-50 cm. Simultaneously lake surface water and lake sediment samples were also collected. The residue of the two herbicide in the soil, water and sediment were monitored at 1, 3, 7,14, 30, 60, 90 and 120 days after application. Laboratory studies encompassing measurements of adsorption, desorption, mobility and degradation of both herbicides were also carried out. Field investigations in the oil palm plantation under natural conditions were conducted to validate the laboratory results. The adsorption and desorption equilibrium time and the effect of concentration, temperature and pH of glufosinate ammonium and triclopyr in both, sediments and three soil textures were investigated. The results showed that the sorption of glufosinate ammonium and triclopyr by the soil is concentration dependent. The results suggested high Freundlitch adsorption distribution coefficients [Kads(f)] for glufosinate ammonium (881.42, 911.05 and 924.10) and low values for triclopyr (18.99, 34.98 and 35.13) in the clay loam and clay soil, respectively. The observed Koc values of glufosinate ammonium were 510.87, 511.62 and 795.91 for clay loam, silty clay and clay soil respectively.The study also showed that the adsorption of triclopyr was higher at low pH, but the adsorption of glufosinate ammonium was higher at high pH for three soil textures. Glufosinate ammonium was not affected significantly (P  0.05) by temperature but triclopyr was affected. Triclopyr adsorbed on to the clay, silty clay and clay loam were 82.27, 78.5, 62.64%, 89.16, 82.57, 77.11%, and 93.32, 86.66,81.22% at temperature 300C, 350C and 400C respectively. Desorption was common to both herbicides. Adsorption of triclopyr to the clay, silty clay and clay loam soil decreased by 66.23, 70.14, 60.37% with NPK and 19.48, 22.38, 22.58% when combined with glufosinate ammonium. Results from the storage stability study found that, glufosinate ammonium in soil samples are stable for 60 days after spraying when stored at −20°C. The half-life of triclopyr were 35.17, 28.99, 32.48 days for nonsterilized and 80.58, 87.72, 96.25 for sterilized soil of clay, silty clay and clay loam respectively. The half-life of glufosinate ammonium were 1155, 990, 990 days in sterile soil and 247.5, 165, 182.36 days in non-sterile clay, silty clay and clay loam soil respectively. The soil column study showed that the downward movement of triclopyr was higher than that of glufosinate ammonium. The mobility of both herbicides was found to be sensitive to the percolated amount and duration of rain whereas the total amount of glufosinate ammonium that was leached from the soil was not affected significantly by increase in the soil moisture or the amount and duration of rain. The field study also showed that both herbicides leached downward to the depth of 10 cm on the day of treatment (0 DAT). Detected glufosinate ammonium and triclopyr in the soil (0-10 cm) ranged from 0.005-0.036 mg kg-1 and 0.004-0.061 mg kg-1 respectively.,Certification of Master's/Doctoral Thesis" is not vailable
Pages:	203
Call Number:	SB951.4.T339 2016 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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