Proyecto green dairyBalances de N-P y márgenes económicos a nivel de explotación

Resumo

For 3 years (2003-2006), 139 pilot faros distributed over 9 regions of the Atlantic Area werestudied within the framework of the Green Dairy Project. The main objectives of this projectwere: study the nitrogen and the phosphorus balances at farm scale and the analysis of the dairymilk economic margin related with the dairy farm management.In the North regions (Scotland, Southern Ireland and Southern England), where the systems arebased on grazing, the nitrogen average surplus are between 134 and 266 kg N ha-1. Thephosphorus surpluses were close to 18 to 40 kg P2O5 ha-1. The economic margin varies from202 to 243 € 1000 L-1. In the South regions (The Basque Country, Galicia and North Portugal),the stocking rate is high and the level of concentrates is also high. The nitrogen averagesurpluses are between 257 and 502 kg N ha-1. The phosphorus surpluses were close to 84 to163 kg P2O5 ha-1. The economic margin varies from 184 to 211 € 1000 L-1. In the West ofFrance (Brittany, Pays de la Loire, Aquitaine), the dairy systems monitored are quite diversified,with both grassland systems and systems with more than 30 % of maize in the forage area. Thenitrogen average surpluses are between 93 and 155 kg N ha-1. The phosphorus surpluses wereclose to 93 to 155 kg P2O5 ha-1. The economic margin varies from 248 to 285 € 1000 L-1.In Galicia and in The Basque Country, the milk prices are the highest, but the margin is one ofthe lowest. Indeed, the costs of feed and fertilisers are very high. In the North region althoughhaving the lowest milk prices, there is a very good control of feed and fertiliser costs making itpossible to have a good margin. The unequal margin between regions is compensated for themilk production volumes.