Environmental impacts of different nitrogen inputs on dairy farms and implications for the Resource Management Act of New Zealand

azote bovin cattle cows dairy farms eau souterraine environmental impact excrements excreta ganado bovino gestion des ressources granjas lecheras groundwater impact sur l'environnement impacto ambiental leaching lessivage du sol losses from soil nitrate nitrates nitratos nitrogen pastizales pastures resource management trifolium repens vaca vache