Structural characteristics and chemical composition of andropogon grass pasture managed under different defoliation intensities and rest periods

Abstract

SUMMARY This study aimed to evaluate the agronomic, structural traits and chemical composition of andropogon grass subjected to different defoliation intensities and rest periods. Two defoliation intensities (15 and 30 cm) and four rest periods (25; 35, 45 and 55 days) were evaluated in a factorial completely randomized design, with four replications. The rest period promoted a linear decreasing effect (P <0.05) on the dry biomass of leaf blades in the two defoliation intensities. The dry biomass of stems showed an increasing linear effect (P <0.05) according to the rest periods in the two defoliation intensities. Production was recorded at 2427.71; 2907.39; 3325.72 and 3749.45 kg ha−1 for the periods of 25; 35; 45 and 55 days, respectively. The dry matter content showed an increasing linear effect (P <0.05) as a function of the rest periods evaluated in the two defoliation intensities. The rest period indicated a decreasing linear trend (P <0.05) for the crude protein content in the two defoliation intensities. A decrease of 0.9 and 0.7 g kg−1 was verified for each day of the rest period. For each additional day in the rest period, there was an increase of 1.2 and 1.5 g kg−1 DM in the neutral detergent fiber content at intensities of 15 and 30 cm. The andropogon grass pasture managed with a 25-day rest period and defoliation intensity of 30 cm showed high leaf/stem ratio and good nutritional value.

Fluxos energéticos e reservas orgânicas de plantas forrageiras

“…This translocation provides greater agronomic stability and forage production potential, which can favor the sustainability of the production system (Sangoi et al, 2012). Concomitantly, new leaves are issued for the plant to reestablish its photosynthetic capacity (Costa et al, 2017). Thus, momentarily, defoliation reduces plant growth due to the decrease in photoassimilate production.…”

Light interception, chemical, and productive characteristics of elephant grass subjected to different cutting intervals

“…According to Costa et al (2017) low frequencies of cutting provide high leaf/stem ratios, which gives the grass better adaptation to grazing or tolerance to cutting, because it represents a moment of phenological development in which the apical meristems are closer to the ground and therefore less vulnerable to destruction.…”