Concentration and plant availability of lead in phosphorus sources marketed in Brazil

Phosphorus fertilizers are intensively used in Brazil since phosphorus often limits the yield in tropical soils. However, these fertilizers can contaminate soils through addition of heavy metals. This work was carried out to study the lead contamination due to addition of four different phosphorus fertilizers as well as the Pb uptake by corn (Zea mays) plants. The fertilizers single superphosphate, triple superphosphate, Araxá rock phosphate, and Gafsa rock phosphate were added at doses equivalent to 0, 100, 300, 500 and 800 kg ha-1 of P2O5. Two successive corn coppings were performed. Gafsa rock phosphate presented the highest Pb concentration. Gafsa application also resulted in the highest Pb concentration in corn shoots