| dc.description.abstract | An investigation was conducted to determine the content and profile
distribution of total copper (perchloric acid extractable) and double-acid
(0.05N HCl + 0.025N H2SO4) extractable copper and its adsorption
characteristics in surface lli1d subsurface soils representing Andisols,
Nitisols and Cambisols. The means of total copper in the A horizons of
Kabete, Gituamba, Njoro lli1dNaivasha soils were 26.6, 29.3, 3.3 and 8.9 ppm
respectively and the means for the B horizons were 24.6, 31.3, 3.1 and 9.7 ppm
respectively. Total copper was found to be generally uniformly distributed
with depth. This uniformity was attributed to the low mobility of coper in
soil. The means of the double-acid (DA) extractable copper in the A horizons
of the same soils (i.e. Kabete, Gituamba, Njoro and Naivasha) were 0.08, 0.36,
0.18 and 0.09 ppm respectively lli1dthe melli1Sfor the B horizons were 0.23,
0.39, 0.22 and 0.06 ppm respectively.
Total and DA-extractable copper contents were correlated with soil pH,
organic carbon and CEC. There was no si@1ificant correlation between total
copper and CEC, organic carbon, pH or DA-extractable copper. A significant
non-linear relationship was found between DA-e~tractable copper and CEC in
Naivasha soil (r2=0.77). The copper adsorption maxima were 299 ~ Cu/g for
Naivasha soil, 264 j..lCgu/g for Gituamba soil, 260 j..lCgu/g for Kabete soil and
164 ~ Cu/g for Njoro soil. The adsorption maximum was highly correlated to
organic carbon and CEC except in Kabete soil. | en |
