Influence of farm yard manure, poultry manure and forest litter on copper solubility in soil and uptake by Phaseohrs vulgaris
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Date
2014-12
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
British Society of Soil Science
Abstract
Long term and intensive use of copper-based fungicides on coffee farms may contaminate soils with
copper. The legacy of copper pollution may pose the risk of contaminating food crops cultivated on
these soils. A randomized block design field experiment at Kilimanjaro, Tanzania was designed to
investigate the effects of different application rates of cattle manure, poultry manure and forest litter
on aqua regia, EDTA and CaC12 extractable copper in soils and copper uptake by bean plants
grown on this long-term copper-contaminated soil (more than 50 yr of copper application). It was
important to examine the potential of the organic amendments in mobilizing or immobilizing copper
and assess the risks of contaminating bean crops at a farm, where the application of organic
amendments was common practice. At harvest, rhizosphere soils were collected and analysed. The
soils were found to have large concentrations of copper, greatly exceeding international standard
levels. Poultry manure applied at 40 tons/ha significantly increased CaC12 extractable copper
compared with the control treatment. Organic carbon, cation exchange capacity, EDTA extractable
copper, aqua regia extractable copper and copper concentrations in bean seeds or leaves were not
significantly changed by the organic matter treatments. The concentration of copper was significantly
less in bean seeds than in bean leaves (P < 0.01). The bean plants did not take up excessive
quantities of copper, and therefore, the risk of copper contamination of bean crops in this farm
appears to be small.
Description
Soil Use and Management, December 2014, Vol. 30, page 480-486
Keywords
Soil contamination, Fungicides, Concentrations, Phaseohrs vulgaris, Copper solubility