Installation of silvopastoral systems with poplar in the Delta of the Paraná River, Argentina

Abstract

The establishment of silvopastoral systems (SSP) in poplar (Populus deltoides ‘Australiano 106/60’) plantations requires specific management strategies. In this context, the combination of the type of tree multiplication material and its palatability may determine the success of SSP establishment. We proposed to create a new technology for the establishment of a SSP with poplar for cattle and multiple uses such as wood production. The first objective was to assess changes in size and morphological characteristics for poplar pole cuttings grown at different densities in a nursery to test suitable multiplication materials for SSP establishment. The second objective was to determine the effect of pole cutting size (or age) on tree growth and sensitivity to damage caused by cattle browsing. In nursery, results showed that the production of multiplication material from larger spacing resulted in better 1-, 2- and 3-year-old pole cuttings, with higher diameter at breast height (DBH), total height, aerial biomass, straightness, conicity and shaft stability. In the poplar SSP, it was determined that the use of pole cuttings with a DBH equal or greater than 6 cm allowed the entry of cattle after the first years of plantation. Poplar leaves and tender branches obtained after spring pruning provided a good supplement to animal diet due to its higher values of crude protein, P and K content and digestibility. It was concluded that the use of poplar pole cuttings as multiplication material promotes the growth of natural pastures and early beef production in poplar SSP on the Lower Delta of the Paraná River.