Site-Specific Effects of Organic Amendments on Parameters of Tropical Agricultural Soil and Yield: A Field Experiment in Three Countries in Southeast Asia

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 effect biochar, compost their combination on maize growth yield, soil physical, biological chemical properties at harvesting time four sites three countries: Thailand, Vietnam Laos. Treatments consisted 10 t·ha?1 cow manure 7 Bamboo biochar combination. Maize biomass production cop yields were recorded for two seasons. Elemental content, pH nutrient availability analyzed after first growing season. also characterized macrofauna abundance water infiltration. Few changes noted yield. Soil parameters showed contrasting, site-specific results. Compost increased carbon, pH, total K N, P especially sandy Thailand. The both could reduce as compared to only treatments. Physical no treatment response. conclude that addition compost, mixture have short-term effects parameters. Their plants is thus mainly related input. site-dependent results despite similar crops, irrigation practices suggest inherent optimization amendment application specific pedoclimatic conditions need future attention.