Horizon 1 1 10 C-ACTI : Communications avec actes dans un congrès international Wetland soils : characterization, classification and utilization : proceedings of the workshop Wetland Soils : Characterization, Classification and Utilization 229-243 RIZIERE ECOLOGIE BIOMASSE MICROORGANISME CARACTERISTIQUE CHIMIQUE MATIERE ORGANIQUE BIBLIOGRAPHIE ECOSYSTEME AQUATIQUE EAU D'IMMERSION SOL INONDE INTERFACE EAU SOL PHILIPPINES MANILLE 1985 1984/03/26-04/05 Manille IRRI fdi:25614 ENG https://www.documentation.ird.fr/hor/fdi:25614 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_5/b_fdi_18-19/25614.pdf Horizon (IRD) Some of the biological concepts and findings relevant to the study of the flooded rice field as an ecosystem are reviewed. The flooded rice field is an artificial ecosystem characterized by extreme instability resulting from frequent destruction of the environment by farming practices. This inhibits the successive development toward marsh and has made monocropping of rice possible for centuries. However, the instability of the ecosystem during the crop has discouraged quantitative approaches by limnologists and ecologists. Therefore topics dealt with here are not supported by a large volume of data. Studies conducted in freshwater ecosystems (lakes, ponds) may help us understand flooded rice fields, but extrapolation is not possible; The floodwater has been neglected in most agronomic, chemical, and soil studies. Its effect on fertility and other properties of flooded rice soils is stressed. Major biological activities in floodwater and soil, recycling of nutrients, and interactions between floodwater and soil are reviewed. (Résumé d'auteur) 076AGRO02 ; 082ECOSYS