Not only in order to determine reasonable application amounts of PCP in terms of soil texture, but also to get basic data for fish-toxicity-free treatment by estimating fish toxicity, some aspects of PCP adsorption were observed taking various paddy soils with different physico-chemical characteristics in the Choongbook Area as samples. The results obtained are summarized as follows:
1. There was a positive correlation between PCP adsorption and clay contents, total nitrogen, organic matter, cation exchange capacity, exchangeable bases, and phosphorus absorption coefficients, respectively; whereas there was a negative one between PCP adsorption and pH. Although they were not significant, it was remarkable that there was a relatively large amount of correlation between PCP adsorption and clay contents, H^+, Mg^(++), and CEC, respectively.
2. PCP adsorption in terms of soil texture was in the order of Clay$gt;Loam$gt;Sandy loam.
3. Although PCP adsorption in the H₂O₂-treated soils decreased remarkably, it was not proportional to the humus contents.
4. The order of PCP adsorption in the exchangeable base-treated soils was H^+-exchanged soil$gt;K^+-soil$gt;Na^+-soil$gt;Ca^(++)-soil$gt;Mg^(++)-soil.
5. Langmuir´s and Freundlich´s adsorption isotherms were applicable to the PCP adsorption, and thereby were able to be calculated maximum adsortion amounts of PCP, bond energy, and the depths of adsorption layers.
6. Maximum adsorbed amounts of PCP were 212.14 ㎎/100gr in Clayey loam, 97.28 to 121.59㎎/100gr in Loam, and 32.92 to 91.74㎎/100gr in Sandy loam, respectively.
7. The depths of mixed layers of limiting application for fish-toxicity-free treatment were 0.88㎝ of the Jinchun soil, the shallowest and 4.29㎝ of the Naesan-ri Sandy loam, the deepest.
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