Níveis críticos e tóxicos de boro em solos de Pernambuco determinados em casa de vegetação

摘要: Research on B availability in soils is essential to assess the crops response different concentrations of available soils. A greenhouse experiment was carried out aiming at studying corn plant (Zea mays) doses (0, 2, 4, 6, and 12 mg dm-3) applied ten from state Pernambuco, Brazil. Available assessed by three extractants: hot water, HCl 0.05 mol L-1, Mehlich-1. The critical toxic levels were determined plants. Additionally, toxicity symptoms plants recorded. Results showed that ranged 0.4 2.3 mg kg-1 1.8 8.3 mg kg-1, respectively. For plants, varied 13.8 129.6 mg kg-1 43.3 372.2 mg kg-1. 0.05 mol L-1 extractant best correlated with content, followed Mehlich-1 water. Both contents inversely related clay organic matter Soils which highest grew presented most acute symptoms. This associated sandy low