The impact of structural adjustment programmes on natural resource use pattern at the household level. The case of Ulanga District, Tanzania

affectation de ressources cash crops cropping patterns cultivos alimenticios cultivos comerciales culture de rapport demografia demographie demography farm inputs food crops hogares households insumos agricolas land use linear programming macroeconomic analysis moyen de production agricole natural resources nutrition physiology physiologie de la nutrition plan de culture plante alimentaire recursos naturales resource allocation ressource naturelle tanzania tanzanie utilisation des terres