The humid tropics are exposed to an unprecedented modernisation of agriculture involving rapid and mixed land-use changes with contrasted environmental impacts. Afforestation is often mentioned as an unambiguous solution for restoring ecosystem services and enhancing biodiversity. One consequence of afforestation is the alteration of streamflow variability which controls habitats, water resources, and flood risks. We demonstrate that afforestation by tree planting or by natural forest regeneration can induce opposite hydrological changes.

The expansion of renewable energy sources is an EU strategy to reduce the dependency onfossil fuels and to curb carbon dioxide emission. According to studies estimating technicalpotentials, significant land resources can be mobilised for the production of energy crops. Weestimate the costs of a policy aiming at a stimulation of biomass and bioenergy production inAustria using a model that integrates the production of food, feed, agricultural and forestbiomass as well as bioenergy products.

The contents of Noumuchou can be divided into six sections: 1) conservation of agricultural land, 2) methods of cultivation, 3) cooperative community cultivation, 4) laying aside produce for times of emergency, 5) growing useful plants and 6) the duties of agriculture-related officials. From these sections it is possible to extract regional characteristics particular to Okinawa. Several points are detailed below. The first concerns technical methods of conserving soil fertility.

The Lusatian lignite-mining district (Eastern Germany) is characterized by a high share of marginal post-mining areas. At these sites, crop yield is generally low, and hence, conventional land use systems often fail in terms of reliable and efficient crop production.

The loss of reactive nitrogen from agriculture into the environment is a major threat to the global environment and a challenge for agri-environmental policy. We therefore investigate the problem of reducing nitrogen losses from agriculture into the environment from an economic perspective. Based on a recursive-dynamic linear programming model, our study reveals that the above difficulty is primarily due to the rigidities associated with the nutrientforage cycle and existing production structures.

Soil physicochemical properties were determined for soils under cropland and forest at the headquarters of the International Institute of Tropical Agriculture in Ibadan, Southwestern Nigeria to examine the 30-year effects of different land use on the fertility of five soil series toposequences underlain by a Basement Complex.