THE DISTRIBUTION OF COPPER, AMINO COMPOUNDS, AND HUMUS FRACTIONS IN ORGANIC SOILS OF DIFFERENT COPPER CONTENT

Publisher Website
Google Scholar
Abstract
Mainly to assess whether long-term use of Cu to mitigate the excessive decomposition and subsidence of some Histosols (organic soils) would influence the nature of their amino-N constituents, fractionations by alkali extraction, acid hydrolysis, or both in sequence, was carried out on a pair each of peats and mucks (hemic and sapric Histosols) taken from a mildly cupriferous bog. The fractions were analyzed for their C, Cu and amino-N components. Acid hydrolysates of the whole soils were also chromatographed to identify and measure their amino-N constituents, these components being known as the immediate sources of plant-available N. Fractions of peats and mucks in which 797 and 2922 ppm of Cu, respectively, have slowed down enzymatic and microbial activities, contained Cu, C and N in proportions similar to those in comparable soil samples with 408 and 1149 ppm Cu, respectively. The N components were distributed among amino compounds in each fraction in a similar manner, irrespective of the Cu contents of fractions or whole soils. Approximately 98% of the soil Cu was found in acid-hydrolyzable fractions, and the amounts of Cu in the fulvic acid (FA) fraction were only 4-8% of the total Cu. The percentage of total Cu in FA was not correlated with total Cu content of the soils. The contemplated use of moderate amounts of Cu for mitigating the subsidence of some Histosols is unlikely to perturb soil N distribution or availability of the N to plants, and unlikely to increase proportionately the amount of Cu amenable to crop uptake or leaching.

This publication has 1 reference indexed in Scilit: