Desempenho de forrageiras em sistemas integrados de produção agrícola

Abstract

The adoption of integrated production systems allows for the intensification of land use through multiple arrangements. Understanding how forage species behave in these systems is necessary to achieve productive, profitable, and sustainable activity. The objectives of this work were: 1- to evaluate the performance of forage species of the genus Urochloa cultivated in consortium with millet in pasture formation; 2- to evaluate the physiological responses of buffelgrass cultivated along the understory existing between the trees and pigeon pea in an Integrated Crop-Livestock-Forestry system. In the first experiment, the cultivation of millet (Cenchrus americanus cv. ADR-500) in monoculture and the intercropping systems of millet + marandu grass (Urochloa brizantha cv. Marandu), millet + xaraés grass (U. brizantha cv. Xaraés), millet + paiaguás grass (U. brizantha cv. BRS Paiaguás), millet + signalgrass (U. decumbens cv. Basilisk), and millet + ruziziensis grass (U. ruziziensis cv. Kennedy) were tested. Ruziziensis grass and signalgrass stood out for their higher dry matter production, with 3.76 and 3.72 t ha⁻¹, and number of tillers, with 114.9 and 102 units m⁻². There was no statistically significant difference in forage quality between treatments during the intercropping period. After intercropping, ruziziensis grass showed the highest green and dry matter production, with 13.94 and 7.45 t ha-1, respectively, while paiaguás grass showed the highest values for dry matter, NDF, and ADF, with 52.79%, 71.46%, and 37.48%, respectively. In biomass stratification, ruziziensis grass and brachiaria grass showed more than 40% of total mass up to 75 cm and 50 cm in height, respectively. The second study was conducted in a split-plot design, with two silvopastoral system arrangements allocated to each plot: SP1 - buffelgrass (Cenchrus ciliares cv. Aridus) intercropped with eucalyptus (Eucalyptus grandis x E. urophylla), and SP2 - buffelgrass intercropped with pigeon pea (Cajanus cajan cv. Iapar 43/Aratã) and eucalyptus. Within each main plot, four subplots were established, defined by distance ranges: 0–2, 24, 4–6, and 6–8 m from the eucalyptus row. Ecophysiological assessments were performed on the buffelgrass. CO₂ consumption ranged from 2.20 to 38.40 in SP1, and from 5.70 to 35.77 in SP2, with higher values at 8 m. The transpiration rate increased from 0.58 to 1.67 in SP2 and from 0.95 to 1.71 in SP1 between 2 and 8 m. Stomatal conductance was highest at a distance of 8 m in SP1, with a value of 0.117. Chlorophyll a levels ranged from 19.2 to 22.7 in SP1 and from 21.7 to 33.0 in SP2, with higher values at a distance of 6 to 8 m.