The 56th Croatian and 16th International Symposium on Agriculture was held in Vodice in the period from 5 to 10 September, where the results of research conducted as part of the Dinara back to LIFE project were presented. This gathering is the largest scientific gathering of agronomic and related professions in Croatia, which also has an international dimension, bringing together scientists from Europe and the world.
In front of the project partner of the University of Zagreb, the Faculty of Agriculture, prof. Josip Leto and prof. Hrvoje Kutnjak have orally presented original scientific paper and a summary in the form of a poster.
The aim of the work of Assistant Professor Kutnjak and Professor Leto was to present the possibilities of estimating the relative productivity of dry rocky grasslands in the foothills of the Dinaric Mountains using Sentinel-2 satellite images. The hypothesis of this paper is that there is a correlation between grassland aboveground biomass from representative grassland areas and NDVI values (normalized differential vegetation index) which would be a prerequisite for calculating grassland productivity in a wider area.
As part of the Copernicus program, the European Commission has in cooperation with the European Space Agency provided an Earth observation service. Sentinel-2A and 2B satellites with their multispectral sensors have found a special purpose for monitoring vegetation changes, which, in addition to a high spatial resolution of 10 m, also ensure a high temporal resolution of images every 5 days.
Professors Kutnjak and Leto, with their work, the first step in making a model for mapping grasslands from the foothills of the Dinara, determined the regularity in the productivity of dry grasslands up to 500 meters above sea level. The obtained projections suggest that 2946.9 ha of the mentioned grasslands in the project area represents an annual grazing potential of about 646.8 AU (animal units), ie, the average productivity of 1.00144 t / ha was calculated, which would theoretically be sufficient to meet the grazing load of 0.219 AU year ha -1 (in such calculations one should be careful because there is still the problem of quality delineation of lawns and other types of land cover via satellite images whose spatial resolution is 10 m, so the detection of grasslands in this case was limited to grasslands which are not in some form of mosaic involving rocks and trees with shrubs). The correlation between grassland yield and NDVI was obtained and described by a linear model y = 378 × X – 89.99 of medium strength (R2 = 0.352) which can be used to map the productive potential of pastures and is the basis for further development of model upgrades for areas with specifics of other altitudes.
In addition to the mentioned work, a summary in the form of a poster was presented, where the goals and vision of the Dinara back to LIFE project were presented in a broader sense, as well as a summary of all research conducted so far (from ornithological, floristic and agronomic), conducted jointly by all project partners.