Effects of Arsenic Contamination on Rice Crop (Oryza sativa L.)
Jahiruddin and M.A. Islam, *M.R. Islam and S. Islam
Department of Soil Science, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh
*Corresponding author. e-mail: mrislam58@yahoo.com
Accepted in May 2004.
Abstract
A pot-culture experiment was conducted at Bangladesh Agricultural University (BAU), Mymensingh during February to October 2002 in order to examine the adverse effect in rice, if any, due to arsenic (As) contamination of soil. Boro rice (dry season rice) and T. Aman rice (wet season rice) were grown in sequence. The soil had 2.6 mg kg-1 background As. Arsenic was added to soil at various rates viz. 0, 5, 10, 15, 20, 25, 30, 40 and 50 mg kg-1 for the first crop only. No addition of As was made to the second crop. Arsenic was added as Na2HAsO4.7H2O in solution. The As contamination of soil significantly affected the yield and yield components of Boro and T. Aman rice. Generally, the values decreased as the doses of arsenic increased. There was more than 45% yield reduction due to use of As at 10 mg kg-1 or above doses. The concentrations of N, P, K and S in grain and straw of both the rice crops were negatively correlated with the As concentrations. The grain-As concentration did not exceed 1 mg kg-1 (the maximum permissible limit) all over the As treatments while the straw-As concentration in all cases went well above 1 mg kg-1. Thus, a soil having more than 10 mg kg-1 As may cause a great yield loss of rice with a concomitant loss of straw quality as animal feed.