PHOSPHORUS EFFECT ON ARSENIC ACUMULATION OF BARLEY (Hordeum vulgare L.) THROUGH IRRIGATION WITH CONTAMINATED WATER

Abstract

Irrigation with water contaminated with arsenic (As) is a risk to human health since it causes the accumulation of this element in the soil and affects crop yield. The objective of this study was to evaluate the effect of phosphorus (P) concentration on irrigation water contaminated with As and its accumulation in the cultivation of barley (Hordeum vulgare L.). The hypothesis was that the accumulation of As by the barley plant is inverse to the concentration of P in the irrigation water. The effect of P was evaluated with a multifactorial experimental design, with a variable level of type 32 . Forty-five seeds were planted in soil piles of 0.126 m2 , with 20.16 L of irrigation with aqueous solutions of As (50, 200 and 400 mg L-1 ) and P (120, 210 and 300 mg L-1 ). We determined the content of As in the soil at the beginning and end of the study, and in the plant at 45 and 90 d after sowing. The analysis of the elements was carried out by ICP-AES after the digestion of the materials with microwaves. The average accumulation of As in the plant (14 101 ± 1 813 mg kg-1 ) with the treatment of 400 mg L-1 of As was 2.4 times higher than in the treatment with 50 mg L-1 . In the treatment with higher concentration of P (300 mg L-1 ) the plant accumulated an average of 6 871 ± 1 051 mg kg-1 , that is, 41.4 % less As than the treatment with 120 mg L-1 . The concentrations of P and As in the irrigation water had a significant effect (p£0.05) in the accumulation of as in the barley plant; in addition, P inhibits the absorption of As in barley.