Effects of compost amended lead–arsenate contaminated soils on total and inorganic arsenic concentrations in rice

ABSTRACT

Rice (Oryza sativa L.), a staple crop for over 50% of the world's population, is also a source of dietary arsenic (As) because of it's efficiencyat accumulating As. Lead–arsenate pesticide was used in agriculture, these soils potentially may be used for rice production. The objective of this study was to determine the effects of compost on total and inorganic As concentrations in rice grown on lead–arsenate contaminated soils. Three lead–arsenatesoils were amended with 10% by weight of compost and planted with rice under flooded and non-flooded conditions. Rice grain yieldwas higher with compost but not flooding. Flooding significantly increased total and inorganic As concentrations. In most cases, rice inorganic Asconcentrations were higher than the limit set by Chinaat 0.2 mg kg⁻¹. Compost at therate used did not reduce rice grain As to safe levels.Lead–arsenate contaminated soils are not recommended for rice production.

KEYWORDS:

• arsenic
• compost
• lead
• organic matter
• rice