This paper clarified the characteristics of soil acidification of haplic Acrisols on ancient alluvial deposit under intensive cassava cultivation in Chau Thanh district, Tay Ninh province, Southeastern Vietnam. Soils were sampled at 3 intervals (0-20, 20-40, 40-60 cm in depth) in 12 sites of intensive cassava cultivation and geochemical parameters related to soil acidity were analysed. | Vietnam Journal of Earth Sciences 39(2), 130-138, DOI: Vietnam Academy of Science and Technology (VAST) Vietnam Journal of Earth Sciences Characteristics of soil acidification of haplic Acrisols on ancient alluvial deposits under intensive cassava cultivation in Chau Thanh district, Tay Ninh province Nguyen Tho*1, Nguyen Thi Hoa2 1 Ho Chi Minh City Institute of Resources Geography, 01 Mac Dinh Chi, District 1, Ho Chi Minh City 2 Saigon University, 273 An Duong Vuong, Disrict 5, Ho Chi Minh City Received 21 January 2017. Accepted 21 March 2017 ABSTRACT This paper clarified the characteristics of soil acidification of haplic Acrisols on ancient alluvial deposit under intensive cassava cultivation in Chau Thanh district, Tay Ninh province, Southeastern Vietnam. Soils were sampled at 3 intervals (0-20, 20-40, 40-60 cm in depth) in 12 sites of intensive cassava cultivation and geochemical parameters related to soil acidity were analysed. The haplic Acrisols under intensive cassava cultivation showed quite high levels of active and exchange acidity (pHH2O ±, pHKCl ±). The hydrolytic acidity and Al saturation level were also high (respectively ± meq/100g and ±) while the exchange alkali and alkaline earth cations were very low (Ca2+ ± meq/100g, Mg2+ ± meq/100g, K+ ± meq/100g in the top layer). This exhibited a limit for mineral nutrients and risk of Al toxicity to cassava plants. If the area for intensive cassava cultivation is expanded and the high-yield cassava varieties are applied, the risk of soil acidification will be expected to be highly serious. It is needed to clarify the processes involved and to establish measures to reduce soil acidification and stabilize cassava production in the study area and Tay Ninh province. Keywords: soil acidification, nutrient, haplic Acrisols, Tay Ninh, cassava. ©2017 Vietnam Academy of Science and .
