Gas Emissions From Buffer Zones In Agricultural Landscapes - Results Evaluation Of The Viii Intecol Congress Symposium.

Increasing productions farmers subsidize energy in order to simplify plant cover structure both within cultivated fields (selection of genetically uniform cultivars and weeds elimination) and within agricultural landscapes (elimination of not productive elements of landscapes like woods, hedges, mid-field small wetlands or ponds and so on being obstacles for work of agromachines). Farmers interfere with natural matter cycles directly by input of fertilizers and pesticides or indirectly by decreasing stocks of organic matter in soils which undermine agroecosystems capacities for chemical storing. These effects of farmers' activities result in the development of a less complex network of interrelations among the components of agroecosystems. As a consequence of this functional simplification, relationships among agroecosystems components are altered, so that there is less tie-up in local cycles of matter. Hence increased leaching, blowing off, volatilisation and escape of various chemical compounds and materials from agroecosystems are appearing. Intensive application of mineral fertilizers and large inputs of liquid manure have brought threats to environment resulting in deterioration of ground and surface waters. Non-point sources of pollution caused mainly by agricultural activity are recognised as one of the first rank factors decreasing quality of inland water ecosystems (Stanners and Bourdeau 1995, European Environment Agency 1998, COM 1999). [ABSTRACT FROM AUTHOR]