Soil retention, leaching and rice uptake of irrigation water As in Bangladesh

摘要

An undisturbed soil column experiment was conducted on four Bangladesh soils to quantify the leaching loss, soil retention and crop uptake of added As. Boro-T. Aman rice were grown in sequence during both 2004 and 2005. Arsenic was added through irrigation water at 0, 1 and 2ppm, the total As loading was 0- 240mg per soil core. The leaching, grain, straw, husk, and postharvest soil As were determined. The soil As retention varied from 78.21%-88.14%, 0.66%- 2.20% plant uptake and 0.59% 2.98% leaching As. The leaching As followed the order of Faridpur>BAU-1> Faridpur-2>BAU-2 soil showing that organic matter, P content and background As was responsible for higher As leaching. Grain, straw, husk and leachate As were increased with increasing As in irrigation water. The highest As uptake was observed in the straw (0. 65% to 2.12% of added) followed by grain (0.005% to 0.041%) and husk (0.003% to 0.039%). The maximum As was retained in the upper layer of the soil column indicating lower mobility of As in soil.