Overview of sandy soils management in Vietnam (oral communication)

In Vietnam, more than 36% of agricultural soils are classified as light textured degraded soils that have a low inherent nutrient supplying capacity, low organic matter content and limited water holding capacity. Among these soils, about half a million hectares are sandy soils mainly located in coastal areas. Communities that are economically marginalized and have few viable options available to address issues of food insecurity, poverty and unsustainable resource management often dominate these soils. This has a direct negative impact on the economic and social fabric of communities that are dependant on natural resources for goods and services in order to sustain already tenuous livelihoods. In this paper, the authors report the results collected from different studies on sandy and light textured soil management in Vietnam including a cooperation project with Belgian universities focused on coastal sandy soils of Central Vietnam and a North Vietnam sandy soils monitoring project. The main hysico-chemical characteristics of sandy soils, nutrient problems and Vietnamese farmers’ experiences on mineral and organic fertility management of sandy soil to overcome the shortages in food and toward a sustainable production are described. The management of these soils requires integrated practices that can increase fertility, and the nutrient and water holding capacity of these soils. Biological management of these soils can be an effective way to increase soil quality through management of biomass, i.e. farmyard manures, crop residues, green manures, and alley cropping. In addition, the effective management of these soils needs careful consideration of appropriate techniques that not only address the issue of low productivity, but to also protect the environment. These soils are prone to significant losses of nutrients through leaching, so that any intensification of production needs to recognize this potential adverse effect and develop management strategies that minimize off-site pollution. These technologies need to be assessed in pilot demonstration plots under local conditions prior to recommending their adoption by the wider agricultural community in coastal areas.