Doan T. T. auteur aut IRD Sisouvanh P. auteur aut IRD Sengkhrua T. auteur aut IRD Sritumboon S. auteur aut IRD Rumpel C. auteur aut IRD Jouquet Pascal auteur aut IRD Bottinelli Nicolas auteur aut IRD text journalArticle eng text/pdf reformatted digital access Organic amendments may improve the quality of acidic tropical agricultural soils with low organic carbon contents under conventional management (mineral fertilization and irrigation) in Southeast Asia. We investigated the effect of biochar, compost and their combination on maize growth and yield, soil physical, biological and chemical properties at harvesting time at four sites in three countries: Thailand, Vietnam and Laos. Treatments consisted of 10 t.ha(-1) cow manure compost and 7 t.ha(-1) of Bamboo biochar and their combination. Maize biomass production and cop yields were recorded for two seasons. Elemental content, pH and nutrient availability of soils were analyzed after the first growing season. We also characterized macrofauna abundance and water infiltration. Few changes were noted for maize biomass production and maize cop yield. Soil chemical parameters showed contrasting, site-specific results. Compost and biochar amendments increased soil organic carbon, pH, total K and N, P and K availability especially for sandy soils in Thailand. The combination of both amendments could reduce nutrient availability as compared to compost only treatments. Physical and biological parameters showed no treatment response. We conclude that the addition of compost, biochar and their mixture to tropical soils have site-specific short-term effects on chemical soil parameters. Their short-term effect on plants is thus mainly related to nutrient input. The site-dependent results despite similar crops, fertilization and irrigation practices suggest that inherent soil parameters and optimization of organic amendment application to specific pedoclimatic conditions need future attention. specialized compost biochar fauna soil physio-chemical properties maize growth tropical soil THAILANDE VIET NAM LAOS ZONE TROPICALE 076 068 11 2 348 [11 ] 2021 https://www.documentation.ird.fr/hor/fdi:010080986 10.3390/agronomy11020348 [F B010080986] https://www.documentation.ird.fr/hor/fdi:010080986 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers21-03/010080986.pdf IRD - Base Horizon / Pleins textes 2021-04-01 2025-02-24 fdi:010080986 fre