Investigating dairy grazing patterns and soil microbial trends in the nitrogen cycle across traditional mountain landscapes

This study investigated grazing impacts on soil biodiversity and soil health indicators on three summer farms in the Paneveggio Natural Park and two permanent farms in Cansiglio. The study area included semi-natural grasslands characterized by a historical human presence. We compared grassland features between management practices (including transhumance in Paneveggio and both meadow and constant presence in Cansiglio) and differences in geographic location. The mean area of the summer farms was 266 ha with a standard deviation of 62 ha while the permanent farms had a mean area of 112 ha and a standard deviation of 9 ha. The study utilized 48 soil sampling locations in each farm for three sampling periods over the course of one year. Cattle grazing patterns were tracked using GPS collars on grazing cattle over the course of summer transhumance from July to September for Paneveggio Natural Park’s summer farms. Points were studied and correlated to slope, distance from concentrated flow paths, and time spent at locations across each summer farm. Soil samples were taken from each summer farm at three sampling timesbefore, during, and after grazing. Microbial populations were analyzed for diversity and abundance in realtime-PCR while soil characteristics included N, C, pH, and texture analysis. Genes used included nosZ for the final step of denitrification and amoA for ammonification. The analysis highlighted great variability in terms of abundance for all genes among all study areas, but the nosZ presence showed no significant difference in pastures between sampling times. These preliminary results outline a constant presence of a complete denitrification process in alpine semi-natural grasslands. Using these results to develop reliable indices for ecosystem services can help researchers, farmers, and policymakers understand the importance of grasslands and their use in creating more sustainable ecosystems.