Nitrogen retention and plant uptake on a highly weathered central Amazonian Ferralsol amended with compost and charcoal

Abstract Leaching losses of N are a major limitation of crop production on permeable soils and under heavy rainfalls as in the humid tropics. We established a field trial in the central Amazon (near Manaus, Brazil) in order to study the influence of charcoal and compost on the retention of N. Fifteen months after organic‐matter admixing (0–0.1 m soil depth), we added 15 N‐labeled (NH 4 ) 2 SO 4 (27.5 kg N ha –1 at 10 atom% excess). The tracer was measured in top soil (0–0.1 m) and plant samples taken at two successive sorghum ( Sorghum bicolor L. Moench) harvests. The N recovery in biomass was significantly higher when the soil contained compost (14.7% of applied N) in comparison to only mineral‐fertilized…

• ÖA
  Österreichischen Akademie der Wissenschaften
• BF
  Bundesministerium für Bildung und Forschung