Ca. Deabreu et al., EFFICIENCY OF MULTINUTRIENT EXTRACTANTS FOR THE DETERMINATION OF AVAILABLE COPPER IN SOILS, Communications in soil science and plant analysis, 27(3-4), 1996, pp. 763-771
Experiments under greenhouse conditions were carried out at the Instit
ute Agronomico de Campinas in order to determine the efficiency of som
e multinutrient extractants on the determination of available copper i
n soils from the State of Sao Paulo, Brazil. These experiments employe
d 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 fer
tilizer. Copper was extracted from the soils before liming and before
each planting using the Mehlich-1, Mehlich-3, or the TEA-DTPA as extra
cting reagents followed by its determination using the inductively cou
pled plasma emission spectrometry (ICP-AES) technique. The wheat and b
eans plants were also analysed for their copper content. The results s
howed that the extraction of the available copper decreased in the ord
er: Mehlich-3, TEA-DTPA and Mehlich-1. The Mehlich-3 (R(2) = 0.80*) a
nd the TEA-DTPA (R(2) = 0.74*) methods explained well the variation i
n the copper concentration found in the aerial part of the wheat plant
s, while the Mehlich-1 (R(2) = 0.45*) results were more appropriate t
o explain the copper concentration found in the aerial part of the bea
ns plants. Both multinutrient extractants, Mehlich-3 and TEA-DTPA, pro
ved to be the best procedures in evaluating copper availability in the
Brazilian soils selected.