Culture du coton et biodiversite des sols de la zone de Guiaro: Impact socio-environnemental de l'utilisation des pesticides.

摘要

In Burkina Faso, the issue of land resources management, mostly this of decrease in soil fertility, is a concern in an unfavorable climate, poverty, illiteracy and demographic boom. The anthropogenic drivers such as the bad utilization of chemicals pollute the soils bringing about ecological, environmental and socio-economic consequences. The magnitude, the extent, and mostly the significance of those practices are not always well understood by farmers, dependently of their interests. Some initiatives are undertaken in order to know the real impacts of those products on the ecological matrices and find the appropriate educational approaches to interest the rural people in the conservation of agro-systems biodiversity.;About the assessment of the biophysical impact of those products on soil biodiversity, we have done a compared inventory of the soil's wildlife and analysis of microbial biomass and soil respiration in two kinds of cotton's plots: the conventional cotton and the biological one. The results indicate a greater abundance of microbial biomass and the "soil engineers" (termites, ants and earthworms) in the plots of organic cotton. But in plots of conventional cotton, the soil respiration is higher and the overall biodiversity of soil macrofauna is greater. These results are probably due to the presence of microorganisms specialized in the catabolism of pesticide residues. Their action releases the energy needed for the activity of other soil organisms.;To find answers about famers behavior in the use of pesticides,we applicate the theories of planned action of Ajzen (1991) and social representations (Jodelet, 1989). The results indicate a high score of anti-environmental behavior among farmers of Boala, in the use of pesticides despite the presence of environmental education programs. However there is no association between this behavior variable and the attitude toward pesticides. This could indicate that knowledge of environmental consequences of these products does not change the behavior of actors. Finally, the only proven determinants of attitudes toward pesticides would be the frequency of technical advice, knowledge of individuals and environmental locus of control These elements of knowledge should inform programs of education on good agricultural practices in the field of rational use of pesticides.;Key words: soil biodiversity, soil respiration, pesticides, environnemental behavior, environmental education.;The resilience of bad farm practices among farmers despite the actions of public-awareness and training and the multiple perceptions about pesticides, have inspired the general issues of our research which aim to know the impacts of pesticides utilization practices on the biodiversity of the soil and to better understand the phenomenon of bad utilization of those products in the zones of cotton growing, in order to improve pedagogical design tools to influence the environmental behavior of farmers. It aims at helping rural populations to rationalize the utilization of pesticides in order to take into account the biodiversity of farm soils.