The objective of this study was to investigate the effect of biochar application (CA) on soil physical
properties and grain yields of upland rice (Oryza sativa L.) in northern Laos. During the 2007 wet season,
three different experiments were conducted under upland conditions at 10 sites, combining variations in
CA amounts (0–16 t ha1), fertilizer application rates (N and P) and rice cultivars (improved and
traditional) in northern Lao