In addition to their production function, grasslands act on the environment in ways such as the protection of the water quality and of the soil quality. How far and under what conditions can these non-productive functions be carried out by perennial grass covers? The main processes described are implied in the nitrogen and the phosphorus cycles, followed by a reminder of the means of limiting the N and the P losses, at the level of the field, of the farm, and of the catchment basin. The land-use pattern (with the proportion of perennial forage covers) is of great importance. The environmental performances of the grasslands are reported for various types of forage systems. It is not easy to weight the different aspects of the water quality that would favor most adequately the effects of the grasslands (areas and management) where the environmental risks are large. Moreau et al (2009) showed that in production systems converted from conventional systems (maize silage) to grassland system, the concentration of nitrogen leaching decrease, leading to a decreased level of N in nearby river water.
The repeated use of cattle slurry on meadow grasses (fescue), also at doses above the limit of 170 kg N/ha/year on soil clayey-silty, does not cause significant nitrate losses from the soil to the waters. An increase of nitrates in the soil is showed after the breaking of the meadow, which then should be followed from the sowing of crops with high nitrogen absorption
- Win win situation for the farms economics
- Lower N leaching in beef systems
- Carbon sequestration is higher in grassland
Difficulties if calculation of nitrogen fertilization needs on grasslands leads to a decrease of the doses on livestock heavy load regions
- Socio-economic resilience: Good grassland management will have an impact on production costs.
- Animal health and welfare: Access to pasture is a key factor for ruminants welfare. As such Grassland management and promotion will have a positive effect on animal welfare.
- Production efficiency and meat quality: Effect is not defined
- Environmental sustainability: Grasslands promotion and good management will have a positive impact on the mains environmental indicators : water quality, biodiversity, carbon sequestration, fertilizer and pesticide use.