2019-01-252019-01-251999p. 141-155. In: Smaling, E.M.A, Oenema, O. ; Fresco, L.O. (eds.). Nutrient disequilibria in agroecosystem: concepts and case studies. Wallingford, Oxon, Cabi Pub. 1999https://hdl.handle.net/20.500.12348/2502A nutrient modelling approach was applied to show how the combination of crops, trees, livestock, and fish, that is, integrated agriculture-aquaculture (IAA), helps in optimizing trophic flows in Asian rice-based agroecosystems. Integrated natural resource management can benefit the farm's nutrient balance sheet and nutrient use efficiency, while generating productive systems.application/pdfBook Chapter