| Autor: |
YOSHITO TOIKAWA, CHOICHI SASAKI, CHIHIRO KATO, NOBUHIKO MATSUYAMA, AKIRA ENDO, JINHUN FAN, TAKEYUKI ANNAKA |
| Předmět: |
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| Zdroj: |
International Journal of Environmental & Rural Development; Jun2020, Vol. 11 Issue 1, p8-17, 10p |
| Abstrakt: |
Combined pollution in farmland soil is a recognized issue in Japan. The measurement of combined pollution has been discussed because the interaction between heavy metals is complex. To date, soil dressing has been the primary method employed to tackle this problem. The objective of this study is to clarify how the percolation patterns of polluted subsoil affect Cu and Cd uptake, and the growth and yield of paddy rice plants. We prepared six stratified paddy-field models to test growth with plowsole and subsoil in open and closed percolation patterns. Each model consisted of a 12.5-cm-thick plowed layer and an upper plowsole made of a non-polluted soil dressing and underlying polluted plowsole and subsoil. Three soils with three levels of Cu contaminations (100, 250, and 500 mg Cu kg-1) were prepared by adding a Cu solution to Cd-contaminated paddy-field soils (1.7 mg Cd kg-1). Three of the six models were open systems, and the other three were closed systems. During the tests, a constant water-ponding system was adopted. As a result, the polluted plowsole and subsoil became oxidized in the open system and reduced in the closed system. The Cu and Cd concentrations in the rice grains were 5% higher in the open models than in the closed models, regardless of the original Cu concentrations in the polluted soils. Interestingly, the Cd concentrations in the grains had an inverse relationship with the Cu concentrations. No significant difference was observed in the growth and yield of the rice plants among the models. We concluded that the Cu and Cd concentrations in rice plants were affected by the percolation patterns of polluted plowsole and subsoil, even though they were covered with non-polluted soil-dressing layers. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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