How does the initial sward height and the grazing period influence the spatial variability of vegetation in deferred signal grass pastures?

• Autor(a) principal: Santos, Manoel Eduardo Rozalino
• Data de Publicação: 2022
• Outros Autores: Márcia Cristina Teixeira Silveira, Dilermando Miranda da Fonseca, Flávia de Oliveira Scarpino van Cleef, Bruno Humberto Rezende Carvalho, Gabriel de Oliveira Rocha
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Bioscience journal (Online)
• Texto Completo: https://seer.ufu.br/index.php/biosciencejournal/article/view/53878
• topic: Brachiaria decumbens syn. Urochloa decumbens; Coefficient of variation; Falling index; Sward height; Urochloa decumbens.; Agricultural Sciences

The objective of this study was to evaluate the spatial variability of structural characteristics of deferred pastures of Brachiaria decumbens cv. Basilisk (signal grass) subjected to associations of sward heights (10, 20, 30, and 40 cm) at the beginning of deferment and grazing periods (1, 28, 56, 85, and 113 days). The experiment was arranged in a split-plot and completely randomized-block design with two replicates. Pastures remained deferred from March to June 2010. From June to the beginning of October 2010, deferred pastures were utilized by steers under continuous grazing and at a fixed initial stocking rate of 3.5 AU ha-1. At the beginning of the deferment, the coefficient of variation (CV) for pasture height was reduced linearly with the pasture height. During the grazing period, in the winter, the CV for pasture height was not influenced by initial pasture height; however, it responded quadratically to the grazing period, with a maximum value of 36.4% at 71 days of the period of utilization. The CV for tiller height was reduced linearly with pasture height at the beginning of deferment but increased linearly along with the grazing period. The initial pasture height did not change the CV of the falling index. However, the latter was quadratically influenced by the grazing period, with a maximum value of 59.5% at 67 days of the utilization period. Signal grass pastures deferred at a lower height have a higher spatial variability of the vegetation. In the grazing period, there are changes in the spatial variability of the vegetation of the deferred signal grass.