Assessments of the values of multi-species grassland for grazing, silage and hay production

Different grassland utilizations are possible: direct utilization by animals (grazing) or forage harvest and conservation (either by ensilage or hay). The grasslands value for these different utilizations depends on many variables of the vegetation. These variables can be aggregated to propose scores for the grazing, ensilage and hay. We developed and used these indicators on four annual mixtures from the seed company FERTIPRADO® set up in south of France. Each of these mixtures is composed of 6 legumes and 2 grasses and managed with no irrigation and no nitrogen fertilizer. Botanical composition, height, and nutritional contents, measured using near infrared spectrometry (NIRS) directly on the sward, were monitored every two weeks. From these variables, indicators were developed using the aggregation tool: TATALE. With TATALE, the input variables are first transformed into scores between 0 and 1 and secondly these different scores are aggregated to obtain summary scores. The parameterization (transformation and aggregation parameters) was made by expertise and literature surveys. These tools provide scores for grazing, silage and hay production values of grassland based on the vegetation state. To illustrate these results, we compared the evolution of one of the four mixtures during the season.