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The application of biochar (biomass-derived black carbon) to soil has been shown to improve crop yields, but the reasons for this are often not clearly demonstrated. Here, we studied the effect of a single application of 0, 8 and 20 t ha−1 of biochar to a Colombian savanna Oxisol for 4 years (2003–2006), under a maize-soybean rotation. Soil sampling to 30(More)
Over the past three decades, large expanses of forest in the Amazon Basin were converted to pasture, many of which later degraded to woody fallows and were abandoned. While the majority of tropical secondary forest (SF) studies have examined post-deforestation or post-agricultural succession, we examined post-pasture forest recovery in 10 forests ranging in(More)
Biochar additions to tropical soils have been shown to reduce N leaching and increase N use efficiency. No studies exist verifying reduced N leaching in field experiments on temperate agricultural soils or identifying the mechanism for N retention. Biochar derived from maize stover was applied to a maize cropping system in central New York State at rates of(More)
Organic and inorganic carbon (C) fluxes transported by water were evaluated for dominant hydrologic flowpaths on two adjacent headwater catchments in the Brazilian Amazon with distinct soils and hydrologic responses from September 2003 through April 2005. The Ultisoldominated catchment produced 30% greater volume of storm-related quickflow (overland flow(More)
In the highlands of Western Kenya, we investigated the reversibility of soil productivity decline with increasing length of continuous maize cultivation over 100 years (corresponding to decreasing soil organic carbon (SOC) and nutrient contents) using organic matter additions of differing quality and stability as a function of soil texture and inorganic(More)
Nutrient leaching in highly weathered tropical soils often poses a challenge for crop production. We investigated the effects of applying 20 t ha biochar (BC) to a Colombian savanna Oxisol on soil hydrology and nutrient leaching in field experiments. Measurements were made over the third and fourth years after a single BC application. Nutrient contents in(More)
Forms and quantities of organic carbon (C) fluxes at the soil surface, and organic C exports from four small (1–2 ha) headwater catchments were quantified and contrasted in the seasonally dry southern Amazon for 1 year to compare C fluxes within the terrestrial ecosystem with exports to the aquatic ecosystem. At the soil surface, the flux of litterfall C(More)
The purpose of this study was to determine if spatially-explicit commercial timber inventories (CTI) could be used in conjunction with satellite imagery to improve timber assessments and forest biomass estimates in Amazonia. As part of a CTI, all commercial trees 45 cm DBH were measured and georeferenced in 3500 ha of a logging concession in NW Mato Grosso,(More)
Extraction of natural gas from tight shale formations has been made possible by recent technological advances, including hydraulic fracturing with horizontal drilling. Global shale gas development is seen as a potential energy and geopolitical "game-changer." However, widespread concern exists with respect to possible environmental consequences of this(More)