Niger is a landlocked country in West Africa located between 11°37´ and 23°23´ north latitude and between 00°10´ and 16°00´ east longitude, with an area of 1,267,000 square kilometers. Niger shares borders with Algeria and Libya in the north, Chad in the east, Nigeria and Benin in the south, and Burkina Faso and Mali in the west. Three-fourths of Niger is cov¬ered by the Sahara Desert. The southern part of the country is in the Sahelian climate zone, with Sudan savannah vegetation.

Canavalia brasiliensis (canavalia), a drought tolerant legume, was introduced into the smallholder traditional crop-livestock production system of the Nicaraguan hillsides as green manure to improve soil fertility or as forage during the dry season for improving milk production.

The major subsistence food systems of the world that feed resource?poor populations are identified and their capacity to supply essential nutrients in reasonable balance to the people dependent on them has been considered for some of these with a view to overcoming their nutrient limitations in sound agronomic and sustainable ways.

Assesses the effect (balance or imbalance) of the present relationships between the natural resource base and human activities; examines the role of some potentially destabilising forces, i.e, international markets, government programmes and socio-economic stratification; and reviews government's role in terms of its contributions to prudent natural resource management and options for the promotion of sustainable rural development.

Summarises the literature on the alleged defects of traditional systems of land tenure in Nigeria. Reviews the provisions of the land use decree and their implications for rural land tenure.

La cuantificacion analitica de suelos y tejidos vegetales es un instrumento efectivo para interpretar la existencia de deficiencias o excesos de minerales. El uso adecuado de esta informacion influye significativamente en las recomendaciones de fertilizantes. Sin embargo, debe admitirse que existe conflicto en las fases de cuantificacion, interpretacion y recomendacion debido a la alta variabilidad existente en estas fases.