Seasonal Dynamics of Biomass Recovery in Amelichloa clandestina Under Non-Selective Grazing in North-Eastern Mexico

The objective of this study was to evaluate the regrowth capacity of Amelichloa clandestina at different regrowth intervals after non-selective grazing in different seasons of the year. The study was carried out on a 2.23 ha−1 site in northeastern Mexico. Plots of 600 m2 were used, with three replications, and were subjected to grazing at 333 LU ha−1 at the beginning of every season, with biweekly evaluations. Dry matter yield (DMY) was determined by harvesting 1 m2 per plot and extrapolating it to kg ha−1. Morphological composition was evaluated from a 10% subsample of the total biomass. The height of 12 plants and light interception were measured with a ruler and a Quantum meter, respectively. The data were analysed using a randomized complete block design (RCBD) with a split-plot in time structure, evaluating Season (S), Days After Regrowth (DAR), and their interaction (S × DAR). Means were compared using the Tukey test in JMP 14 Pro. In autumn, DMY peaked at 535.0 kg ha−1 at 90 DAR (p ≤ 0.05), accompanied by a maximum canopy height of 28.7 cm and a light interception of 30.3% at the same interval. Leaf biomass was highest in autumn, with a seasonal mean of 220.8 kg ha−1 across all regrowth intervals. A significant correlation was found between plant height and light interception (r = 0.67, p ≤ 0.001). Autumn favoured A. clandestina productivity under a high stocking rate.