Trends in Intensive Temperate Grassland Systems

Intensification of grassland in temperate zones has been successful in substantially increasing output of animal products per unit area of land. This trend is unlikely to continue, however, where intensification has been supported by large subsidies, as in EC countries. The high costs of both subsidising the production systems and the export of surplus products is not sustainable. The distortion in world trade caused by such policies combined with concerns over the environmental implications of intensification has already led to CAP reforms in Europe to de-intensify ruminant. livestock systems. Liberalisation of world trade through GA TT could lend to further reductions in subsidy. This would allow countries with poorly developed grassland to intensify their production systems. In considering intensification, the socioeconomic implications of production systems are important. Farmers are rarely profit maximisers and factors such as the amount of physical work required, the lifestyle and status in the local community often dictate the chosen system of production. There are concerns about the use of nitrogen (N} fertiliser on grassland. The recovery of N inputs in animal products is low (14· 17%) and consequently there are substantial losses to the air and into groundwater. Fertiliser recommendations for farmers are often based on mown plot trials which overestimate farm requirements. A consequence is that farm responses to N fertiliser under grazing conditions may often be uneconomic. In countries utilising high N systems, a move to grass-legume swards in the future is a likely trend. In many countries conserved grass forages contribute a major proportion of ruminant diets. Pollution problems from silage effluent where grass is unwilted (a common practice in the UK) are leading to a return to willing where climatic conditions permit. Technological developments in biological (bacterial and enzyme) additive production are resulting in silages of enhanced feeding value. Nevertheless, the breeding of earlier-maturing maize varieties is resulting in the replacement of grass silage with maize silage in many countries.