Report
Overseas Field Training：Evaluation of sediment and carbon losses associated with soil surface erosion
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| Our study group | Data collection |
Place : Vietnam Forestry University, Vietnam
Date : 25 August– 25 September 2010
＜Report by Pham Anh Thi Quynh＞
On September, 2010, I had a field trip to Vietnam Forestry University, Vietnam, under the guidance of Professor Takashi Gomi and Dr. Phung Van Khoa (The lecturer of Vietnam Forestry University) with title: “Evaluation of sediment and carbon losses associated with soil surface erosion”. In this overseas field training, my main objective was evaluation of potential soil erosion and soil nutrient conditions (C, N, and C/N) in various land use types in the low mountainous area of Northern Vietnam. We investigated soil erosion and nutrient condition in 10 landuse types in the low mountainous area of Northern Vietnam. Ten landuse types including forest, agriculture, shrub, landscape plantation and bare land had been selected as dominate landuse types based on LANDSAT image and supervised classification. All of understory vegetation and litter were separately collected from 3 plots in each of the ten landuse types. A soil sample at 5 cm depth from surface was also collected. The findings of this study were the follows. (1) Soil erosion estimated by height of soil pedestals varied from 0 to 3 mm among land use types. (2) Even in the forested land and agriculture land, we observed significant amount of soil erosion features depending of the amount of understory vegetable and litter cover. (3) Amount of litter and vegetation also control the amount of soil total carbon(C) and nitrate (N). (4) Relationships between soil C (and N) and biomass probably related to carbon/nitrogen immobilization and mineralization processes associated with soil erosion and production processes. For the management application, our findings suggested that more than 130 to 150 g/m2 of vegetation (dry mass) are required for the conservation of soil in forested and agriculture lands. Therefore, such information can be important for developing guidelines of land management in the low mountainous area of Northern Vietnam.
Supervisor / Instructor and students traveled with :
Prof. Takashi Gomi, Dr. Phung Van Khoa, Bui Xuan Dung.