ABSTRACT
This chapter explains the general principles and legislative background to organic farming. The practical implementation of these principles is then reviewed in detail in relation to grassland management. In particular, the organic approach to the major management challenges faced by grassland farmers is examined; nutrient supply to the crop, control of weeds; and maintenance of animal health. These are areas that, in a conventional situation, would be dealt with primarily through inputs of fertilizers or agrochemicals, but which, in the organic situation, must be addressed using an ecological approach, working with biological and ecological processes.
For nitrogen (N) nutrition, the importance of biological N-fixation by herbage legumes and enhancing N-mineralization is emphasized. For phosphorus and potassium supply, the priority should be an efficient nutrient cycling system, in order to minimize losses from the farm. Control of perennial weeds such as dock and thistle is a difficult challenge. The farmer needs to base the control strategy on altering the management factors that cause the problem. Specific weed control practices are suggested. A particular management focus for organic grassland farmers is the maintenance of good health in grazing animals, especially the control of internal parasites such as intestinal worms in young animals. A range of management options is suggested.
The potential of a range of herbage species for sowing in organic grassland is described and the impact of organic grassland on biodiversity and the environment (nutrient losses and energy consumption) is reviewed. It is recognized that productive, legume-based sown pastures are unlikely to be species rich, and N losses to the environment will depend on the overall supply of N in the system. Potential livestock output per hectare, based on research on organic temperate grassland, is reviewed, and the major issues and challenges for the future discussed.
