Dr Thuy Doan Thu1
1Doan Thu Thuy, Soils And Fertilizers Research Institute, Việt Nam, 2Phimasone Sisouvanh, National University of Laos, Lao PDR, 3Thanyakan Sengkhrua, Land development department regional 10, Ratchaburi , , Thailand, 4Supranee Sritumboon, Land development department regional 5, Muang, Thailand, 5Cornelia Rumpel, CNRS, Sorbonne Université, IRD, Institute of Ecology and Environmental Sciences (UMR iEES-Paris),, France, 6Pascal Jouquet, CNRS, Sorbonne Université, IRD, Institute of Ecology and Environmental Sciences (UMR iEES-Paris),, France, 7Nicolas Bottinelli, CNRS, Sorbonne Université, IRD, Institute of Ecology and Environmental Sciences (UMR iEES-Paris),, France
Organic amendments may improve the quality of sandy and acidic tropical agricultural soils in Southeast Asia . We investigated the effect of biochar, compost and their combination on maize yield, soil physical, biological and chemical properties at harvesting time at four sites in Thailand, Vietnam and Laos. Maize irrigated crops were planted in two seasons. The soils were amended with chemical fertilizers or with 10 t.ha-1 of cow manure compost and 7 t.ha-1 of Bamboo biochar and their combination. Soils were analyzed for elemental contents and N, P and K availability. We also characterized soil macrofauna composition and water infiltration. Few changes were found for biological and physical parameters. Maize yields and chemical soil parameters showed contrasting, site specific results. Compost and biochar amendments tended to increased soil carbon, NO3- and PO4- availability but not K+ availability especially for sandy soils in Thailand. The combination of both amendments decreased P availability and tended to decrease NO3- and K+ availability at all sites. We conclude that compost and biochar amendments have little short-term effects on physical and biological parameters of tropical soils but change to some extent chemical parameters and maize yields.
Key words: compost, biochar, macrofauna, soil health
Doan Thu Thuy have 20 years research experience in bio-technology, agronomy and soil ecology. I spent 12 years working on improve the quality of crop production via using the Biotechnology (in vitro propagation and molecular technique). I have 8 years studying the effect of organic amendment like compost, vermicompost and biochar on plant growth, soil and water quality. Since 2008, my work as part of the activities in the MSEC (Multi scale Environmental Change anagement Soil Erosion Consortium SFRI-IRD-IWMI project) and LMI LUSES project: dynamic of Land Use changes and Soil Ecosystem Service, fundamental findings were the understanding of the ecological concepts. Furthermore, the extension of an economical and friendly model has also been trained to Farmers in Laos and Viet Nam via the NGO’s programs