Adoption d'innovations agroforestieres a Barra do Turvo (Sao Paulo, Bresil)Adoption of agroforestry innovations in Barra do Turvo (Sao Paulo, Brazil)

摘要

Agroforestry has been developed for six years in Barra do Turvo. In this district of the Vale do Ribeira, the poorest area of the State of Sao Paulo, in Brazil, these farming systems bring technical alternatives to the family agriculture in crisis facing many problems: drop of soil fertility, rigid environmental laws, shortage of land and difficulties with the commercialization of products. In 2002, less than 10% of family farms in the district were involved in the process of technical change towards agroforestry. Theses new farming systems are developed according to a model used in a similar context, in the Mata Atlantica (Brazilian Atlantic forest), which is degraded by agricultural activities. Agroforestry "based on regeneration" rests on the principle of plant species succession and aims at a sound management of natural resources. In Barra do Turvo, this model is often used in abandoned banana plantations but also on soils degraded by practices unadapted to sloping and erosion-prone lands. In other situations, the innovation is simply added to traditional farming systems (combination of trees and crops, improved fallows using Cajanus cajan, enriched forests). By means of a monthly survey of farms over one year, technico-economical and social impacts of the introduction of these systems were evaluated. Farmers have developed different strategies regarding innovation: some of them have mastered the agroforestry techniques of the model, sometimes transforming the products of agroforestry; others are producers in transition who combine crops and agroforestry techniques or use agroforestry to diversify their livelihood systems. Finally, some farmers are only interested in agroforestry to get resources from the project and a means of commercialization. The agroforestry project provides farmers with a regular income. The income of farmers without cows or of farmers who are in the process of capital accumulation with animals is improved but work productivity is not greater than in shifting cultivation. However, the introduction of agroforestry is economically risky because above all it requires a lot of work. In addition, the average cost of implanting agroforestry is lower than the cost of systems that have the same aim of covering the soil. As for the social impact, new jobs are created. Also, farmers are becoming more aware of environmental issues. However, at the same time inter-generation conflicts and exclusion appear. On the other hand, farmers' networks are activated or re-activated (mutual aid groups working in agroforestry and organizations of producers for commercialization): meeting and discussion places are created, which is very favorable for mobilizing of knowledge and for creating new common norms. In conclusion, this study of impacts shows that subsidizing agroforestry is legitimate in pursuing sustainable development. But it also shows the many deficiencies of the agroforestry project. The actual access to markets should be re-enforced, involving as much as possible the producers in searching new ways of commercialization. It is also important to re-enforce the technical follow-up and to better exploit local biodiversity and new vegetal species to be introduced. Finally, it is essential to guarantee the right of using the native species that are present in the future agroforests to ensure the sustainability of these perennial systems.