Productive and nutritive traits of Piatã palisadegrass after thinning the forest component of a silvopastoral system in southeastern Brazil

Abstract

AbstractSilvopastoral systems (SPSs) are sustainable alternatives for pasture intensification. Management practices such as thinning are options to diminish competition for resources between pasture and trees, ensuring appropriate forage production. The objective of this study was to evaluate the productive and nutritive traits of Piatã palisadegrass (Urochloa brizantha cv. BRS Piatã) after thinning the forest component of a SPS. Forage production and nutritive value, along with microclimate variables were assessed in a SPS and in an intensive system (INT) in São Carlos-SP, Brazil, from 2016 to 2018. The INT was a full sun pasture of Piatã palisadegrass, while the SPS was established with Piatã palisadegrass shaded by eucalyptus (Eucalyptus urograndis clone GG100) spaced 15 × 2 m but thinned to 15 × 4 m before the onset of the experiment. In the SPS, measurements were made under the tree row (SPS_1), 3.75-m (SPS_2), 7.5-m (SPS_3) and 11.25-m (SPS_4) distant from the North row. Forage accumulation in the two systems were similar, whereas the pre-grazing forage mass in most of the SPS positions were smaller than that of the INT during the autumn of 2017 and summer of 2018. Crude protein (CP) content was greater in the SPS than in the INT in most positions and seasons. Forage production was favoured by the thinning of the trees mainly in the seasons close to the event, while forage CP was consistently greater in the understory pasture. Thinning of trees in SPSs can be adopted to provide forage production similar to intensive pastures with higher protein content.