Nutrient management in low input grazing–based systems of meat production

Abstract

Abstract. Low input grazing‐based meat production is often practised on land where alternative land use is restricted and where high biodiversity warrants specific environmental payments. Although these systems are characterized by low external nutrient inputs, significant nutrient losses may occur per unit of produce, even though losses per unit area are low. If the aim is to have animal production without further eutrophication of watercourses, these losses should be minimized,. However, if nutrient‐poor grasslands characterized by high biodiversity are the aim, some losses must be accepted to balance nutrient inputs by atmospheric deposition. The impact of grazing animals on nutrient dynamics in grasslands is reviewed in this paper, and options to further improve nutrient management are discussed. It is concluded that nutrient management should largely be addressed indirectly through management of animal behaviour in relation to grazing and supplemental feeding, as well as through optimization of the seasonal distribution of livestock size. A case study indicated that N losses from a cattle farm could be reduced considerably by these means, while animal production could actually be improved. Sustainability issues and trends in legislative and social pressures on low input grazing‐based systems of animal production are discussed in relation to nutrient management and practical recommendations.