Effects of aeration on arsenic and its subsequent effects on growth and macroelements of rice

Effects of aeration on arsenic (As) and its subsequent effects on rice growth (Oryza sativa L. cv. Akihikari) and macroelements (P, K, Ca and Mg) were investigated in hydroponic condition. The treatments were control (T1), aeration (T2), 1 ppm As (T3) and 1 ppm As + aeration (T4). Arsenic was added as sodium meta-arsenite (NaAsO2). Plants were grown up to 21 days after treatments (DAT) in greenhouse. After harvesting, roots and shoots were dried and digested separately with H2SO4-H2O2 mixture for measuring P, K, Ca, Mg and As. In T3, P concentration was more in shoots (9.67 mg g-1) compared to that in roots (1.47 mg g-1) with reference to T1 (7.47 mg g-1) and (2.13 mg g-1), respectively. Potassium concentration was less in shoots and roots as compared with T1. In T4, K concentration was increased in shoots compared to only T3 but still lowered than T1 and T2 treatments. In T4, Ca concentration was increased both in shoots and roots compared to T1, T2 and T3 treatments. There was no significant difference between T3 and T4 treatments for K, Ca and Mg accumulations in shoots, indicated that aeration did not have any significant role on As-toxicity reduction in this experimental system. In T3 and T4 treatments, P translocation was increased but did not change K, Ca and Mg translocation. Arsenic concentration in root was almost 20 and 14 times of that in shoots in with and without aerated conditions, respectively.