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Book of Abstracts

11th IFOAM
Scientific Conference
11-15 August 1996
Copenhagen, Denmark

Abstract front page
Subject index
Athor index

Special Presentations

Soils: Sustainable management of the agricultural resourcebase F16

Bourguignon, Claude

L.A.M.S. F-21210 Marey-Sur-Tille, France

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Our world wide experiment of soils biology allow us to advance that organic agriculture is a good solution for sustainable agriculture in temperate countries but the best one for tropical countries. Our studies are based on biological activity measurements of soils under natural vegetation. The reason of this choice is due to the fact that natural systems are sustainable by definition since they last so long time ( 30 millions of years for amazonian forest). In nordic countries, organic matter contents of natural soils are very high due to a low biological turnover (50% of the carbon is in the soil). In these cases, soil reserves of nutriments are high and it is impossible to increase yields by organic farming. It is just possible to maintain yields with lower costs and reduced use of fertilizers and pesticides. In equatorial countries, organic matter contents of soils is very low, due to a very high turnover of carbon (5% of the carbon is in the soil). In these soils, C.E.C is very low and nutriments reserves too. In these conditions the chemical agriculture is unenforceable without strong environmental disasters. The natural ecosystems are sustainable because they have developped very efficient biological processes : Soil aeration by fauna, a zero level of lixiviation despite high rainfallsby deep roots, biological assimilation process for precipitated elements and biological protection again soil acidity and aluminium toxicity. The knowledge and the application of these biological systems allows to developp a highly productive sustainable agriculture as we show with our results on rice and soybean production in Mato Grosso in Brazil. In south countries organic farming can't be ignored.