Efficiency of multinutrient extractants for the determination of available copper in soils

Abstract

Abstract Experiments under greenhouse conditions were carried out at the Instituto Agronomico de Campinas in order to determine the efficiency of some multinutrient extradants on the determination of available copper in soils from the State of Sao Paulo, Brazil. These experiments employed 31 soils using wheat and beans as test plants. All soil samples were limed to increase the soil pH to 6.0 and manured with copper‐free fertilizer. Copper was extracted from the soils before liming and before each planting using the Mehlich‐1, Mehlich‐3, or the TEA‐DTPA as extracting reagents followed by its determination using the inductively coupled plasma emission spectrometry (ICP‐AES) technique. The wheat and beans plants were also analysed for their copper content. The results showed that the extraction of the available copper decreased in the order: Mehlich‐3, TEA‐DTPA and Mehlich‐1. The Mehlich‐3 (R2 = 0.80**) and the TEA‐DTPA (R2 = 0.74**) methods explained well the variation in the copper concentration found in ...