要 旨：
More then eighty five percents of land areas in North Vietnam are considered
as sloping land. Current production practices cause soil loss and destruction
as the soils are deeply weathered, poor in nutrient, and highly vulnerable
to erosion.
From 1999 to 2002 a participatory watershed research and application was
carried out in Thanh Ha farm, Kim Boi district, Hoa Binh province. The
main aim of the research was firstly to introduce improved soil, water
and nutrient management technologies and secondly to evaluate suitable
cropping systems for efficient use of natural resources. The approach we
have taken was to ensure maximum participation of farmers in planning and
execution of all activities. Various measures for the movement of water,
soil, and nutrition have been undertaken. As a result, we found that there
was about 25-30 cm increase in the groundwater level in the benchmark watershed
wells compared to those outside the watershed. In addition application
of polyethylene mulch resulted in doubling the groundnut yield. Application
of the improved practice has resulted in increasing of 8% in yield of maize
with the reduction of 28% in using nitrogen fertilizer. Large scale on-farm
demonstrations were conducted with improved varieties of soybean, groundnut
and watermelon. Farmers were highly impressed with the legumes crop and
showed interest in planting the crops in large scale plantation with more
than 50% of the total land area.
Thus, watershed based integrated natural resources management technologies
has offered opportunities for crop diversification, improving soil health
and ground water and reducing the soil erosion and land degradation in
major sloping land of northern Vietnam.
