This study was conducted to compare a real production of livestock effluents with potential uses of these effluents, which are in the hypothetical domain. Statistical data used for the characterization of existing effluent products, crops and ponds in Vietnam are established, and the methods and hypothesis for calculation of quantities of farm fertilizer potentially usable for crops and fish farm ponds, are presented. Three scenarios were selected for the calculation of mass balances: a current scenario in 2005 and two perspective scenarios in 2010, following an approach based on a reasoned practice of fertilizer application. Results of estimation of the farm fertilizer produced in the Thai Binh province and the results of calculations of mass balances obtained according to the three scenarios are presented, with emphasis on the results given by the approach based on the current usage practices of farm fertilizer. Finally, the limitations and perspectives for improvement of fertilizer application in association with the local stakeholders are discussed