Nutrient availability in an ancient Anthrosol and Ferralsol; Amazon basin-Report

Plant and Soil 249: 343?357, 2003.
COPYRIGHT 2003 Kluwer Academic Publishers. Printed in the Netherlands.

Nutrient availability and leaching in an archaeological Anthrosol and a
Ferralsol of the Central Amazon basin: fertilizer, manure and charcoal
amendments

Soil fertility and leaching losses of nutrients were compared between a Fimic
Anthrosol and a Xanthic Ferralsol from Central Amaz?nia. The Anthrosol was a
relict soil from pre-Columbian settlements with high organic C containing large
proportions of black carbon. It was further tested whether charcoal additions
among other organic and inorganic applications could produce similarly fertile
soils as these archaeological Anthrosols. In the first experiment, cowpea
(Vigna unguiculata (L.)Walp.) was planted in pots, while in the second
experiment lysimeters were used to quantifywater and nutrient leaching from
soil cropped to rice (Oryza sativa L.). The Anthrosol showed significantly
higher P, Ca, Mn, and Zn availability than the Ferralsol increasing biomass
production of both cowpea and rice by 38-45% without fertilization (P < 0.05).
The soil N contents were also higher in the Anthrosol but the wide C-to-N
ratios due to high soil C contents led to immobilization of N. Despite the
generally high nutrient availability, nutrient leaching was minimal in the
Anthrosol, providing an explanation for their sustainable fertility. However,
when inorganic nutrients were applied to the Anthrosol, nutrient leaching
exceeded the one found in the fertilized Ferralsol. Charcoal additions
significantly increased plant growth and nutrition. While N availability in the
Ferralsol decreased similar to the Anthrosol, uptake of P, K, Ca, Zn, and Cu by
the plants increased with higher charcoal additions. Leaching of applied
fertilizer N was significantly reduced by charcoal, and Ca andMg leaching was
delayed. In both the Ferralsol with added charcoal and the Anthrosol, nutrient
availability was elevated with the exception of N while nutrient leaching was
comparatively low.

This report can be found at:
"http://www.css.cornell.edu/faculty/lehmann/publ/PlantSoil%20249,%20343-357,%20
2 003%20Lehmann.pdf"