Managing eucalyptus trees in agroforestry systems: Productivity parameters and PAR transmittance

Agroforestry systems, in which trees and crops are cultivated rotation, succession, or association with pastures, alternatives for the sustainable implementation of agriculture. This study estimated productive characteristics from eight years old eucalyptus different agroforestry systems transmission photosynthetically active solar radiation (PAR). These were composed a pasture palisade grass (Urochloa brizantha “BRS Piatã”) (Eucalyptus urograndis “GG100”) planted April 2011 single rows 15 m apart 2 in-row spacing, totaling 333 ha?1. In 2016, half thinned, spacing was changed to × 4 m. The two then evaluated using an integrated crop-livestock-forestry system (agrosilvopasture renewal, ICLF) livestock-forest (silvopasture no ILF). Each had 12 paddocks 5000 m2. ICLF, renewed one-third each replication area (two paddocks) per crop year, where simultaneously sown corn silage. Pasture renewal carried out 2013–2014, 2014–2015, 2016–2017, 2017–2018 growing seasons. Data collected 2016 June 2019, when 110 harvested determine wood volume 28 gather rings samples canopy, roots, carbon content. data used build equations estimating stem (m3 tree?1) tree biomass (kg tree?1). Stem diameter at breast height (DBH, 1.3 above ground) (H) measured 10% plot estimate biomass; these compared by t-test (5%). PAR continuously 2013 2019 70 cm aboveground linear quantum sensors four ICLF positions across line. Using data, = exp[(? -10.21 + 1.68 ln(DBH)+1.29 ln(H)] exp[?3.88 2.41*ln(DBH)+0.62 built. greater (225.7 m3 ha?1) than ILF (215.2 (p 0.0369). total 148.3 Mg ha?1 141.0 ILF, significant differences between systems. accumulated 64.5 after implementation. basal both showed strong relationship pasture.