The fate of endosulfan in tropical soil-plant systems : lysimeter studies with nuclear techniques | |
| Author | Patana Anurakpongsatorn |
| Call Number | AIT Diss. no.EV-98-1 |
| Subject(s) | Plant-soil relationships Pesticides--Environmental aspects |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Technical Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | This research study was conducted to determine the fare of endosulfan, cyclodiene organochlorine pesticide in tropical soil-plant systems using agricultural lysimeter with nuclear techniques. Two types of soils were selected from different locations in Thailand. Rangsit soil represented low land soil and Phrabat soil represented upland soil. Both types are acid soil which predominately cover in large scale of cropping area in Thailand. 14C endosulfan was used as a tracer to follow the fate of endosulfan in this study. It was found that Rangsit soil had more adsorption to endosulfan as compared to Phrabat soil, especially in plow soil layer. Endosulfan indicated hysteresis phenomena in adsorption-desorption processes in all types of studied soils. Comparing between biotic and abiotic soils in biometer flask studies, intrinsic soil microorganisms were well established in mineralization of endosulfan to C02. Phrabat plow layer soil showed the most severe degradation, 19.36 % of the initial application, while mineralization in Rangsit soil occurred only 2.94%. Chromatographic packed-soil column was used to study the relative mobility and distribution of endosulfan in soil. With water saturated flow and gravity, Phrabat soil showed much more relative mobility and distribution than Rangsit soil. This was agreed with soil permeability of the two soils which were 0.34 and 9 .16 mmlh for Rangsit soil and Phrabat soil, respectively. This result was in agreeable with the adsorption coefficient (kd) of the two soils which was higher in Rangsit soil compared to Phrabat soil. The distribution of endosulfan was found mostly in the top 10 cm of soil. As expected distribution to deeper extend was observed in Phrabat soil. In semi-field studies, lysimeter studies, lysimeter was filled with soil layers similar to the actual field conditions. Soil was filled up to get 20 cm deep of sub-soil and 20 cm deep of plow soil layer and well stabilized with wet-and-dry condition. Two crops were selected as indicator for plant uptake of endosulfan from soil in this study. · Mung . bean was selected · for first field crop followed by Chinese kale as a second vegetable crop. Endosulfan was foliage application to mung bean only. Whereas Chinese kale was used as a ·model plant to study the bioavailable of endosulfan contaminated in soil to food crop. At harvesting, all separated parts of mung bean plant (leaf, stem, seed, and root) were investigated and found contaminated with endosulfan. The distribution of endosulfan in soil was found in almqst all layers of soil, greater amount was found mostly in the top 10 cm layer. Endosulfan was distributed much deeper in Phrabat soil lysimeter thah Rangsit soil which was confirmed· by a soil column studied. No activity of endosulfan was detected in leachate coming out in a very small amount from lysimeter. lll At harvesting time of Chinese kale which was grown continuously after harvested mung bean, endosulfan residue was found in Chinese kale showing that endosulfan contaminated in soil was bioavaialable to food crop. Autoradiography confirmed that Chinese kale uptake endosulfan via root, but translocation to shoot part was quite restricted. Subsequently, endosulfan activity was found in root and lower leaves only. The distribution of endosulfan in soil after harvesting Chinese kale was similar to the first collecting after mung bean. Greatest amount of endosulfan was still distributed in 10 cm layer of Rangsit soil while in Phrabat soil, distribution of endosulfan was far to 30 cm deep of soil. However, no endosulfan activity was found in leachate coming out from lysimeters at the end of this study. In conclusion, endosulfan as a member of organochlorine pesticide, had a high persistence in tropical soil-plant systems. With two cropping period of about 107 days of mung bean and Chinese kale incombination, residues of endosulfan are still presented in soil which indicated its bioavailable to crop. Distribution of endosulfan in tropical soil-plant systems was possible far below root zone. Fortunately, with a great adsorption capacity to soil particles, the possibility to reach ground water was limited. However, moving with soil particles by surface runoff seems to pose a potential risk to waterbodies and need a further study. |
| Year | 1998 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Environmental Engineering (EV) |
| Chairperson(s) | Preeda Parkpian ;Samorn Muttamara; |
| Examination Committee(s) | Takisawa. Satoshi ;Hansen, Gunner K. ;Reutergardh, Lars Baetz ;DeLaune, Ronald D.; |
| Scholarship Donor(s) | Royal Thai Government ; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 1998 |