Soil Nutrient and Rice (Oryza sativa L.) Growth Characteristics under Different Arsenic Contamination Levels

초록

Arsenic (As) contamination in agricultural soils causes adverse influences on crop growth and yield, and serioushuman health issues. The objectives of this study were to (a) verify the change of chemical properties underdifferent As contaminated soils, (b) compare the growth and yield of rice grown in different concentrations ofAs-contaminated soil, and (c) investigate the relationship between total As and phytoavailable As concentrationsin the soil and As concentrations accumulated in the polished rice. Rice plants were cultivated in a greenhouseunder six As concentrations: 6 (control), 25, 34, 42, 50, and 59 mg kg-1. Soil As concentration showed significantpositive correlations with NH4-N, available P2O5, and exchangeable K. A significant negative correlation wasindicated between soil As concentration and NO3-N, whereas no significant correlation was found betweensoil As concentration and total N. Increased soil arsenic decreased plant heights and number of tillers; causedyield reduction depending on the increasing As concentrations in soils. The yield of As-exposed rice plantswas 38 - 90% less than that of untreated plants. This was mainly due to the reduced number of panicles perplant and spikelets per panicle. We also found that total and phytoavailable As concentrations in the soil forthe edible limit of As in polished rice (0.2 mg kg-1) were 21.85 and 1.04 mg kg-1, respectively.

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