Residual heights alter forage production parameters and nutritional value of dwarf elephant grass [Cenchrus purpureus (Schumach.) Morrone]

This is the authors' abstract. We don't add key points for this paper.

Aim of study: This study aims to ascertain the appropriate residual height for the dwarf elephant grass [Cenchrus purpureus (Schumach.) Morrone] ʻBrs Kurumiʼ by concurrently evaluating its forage production, morphological composition, and nutritional value. Area of study: Rio Grande do Sul, Brazil. Material and methods: The dwarf elephant grass ʻBrs Kurumiʼ was evaluated over four consecutive growing seasons in a randomized complete block design with five treatments and four replications. Treatments consisted of residual cutting heights (20, 30, 40, 50, and 60 cm), with a target management height of 80 cm. Parameters assessed included forage production and its morphological composition, population density of basal tillers, and nutritional value. Main results: The relationship between morphological components and nutritive value was highlighted. Residual cutting heights between 40 cm and 50 cm modified the pasture structure to balance the quantity [accumulated total dry matter production ranged from 8,242 kg/ha (40 cm) to 6,916 kg/ha (50 cm)], while nutritive value (crude protein content remained stable at 14.6% for both heights. Research highlights: Dwarf elephant grass ‘Brs Kurumi’ exhibited changes in forage production, morphology, and nutritional value across residual cutting heights. At recommended levels (50 cm and 40 cm, or 60% and 50% of the target height), the grass responded similarly to disturbance, suggesting that plants’ phenotypic plasticity helped balance morphological components and nutritive value, facilitating to their adaptation to imposed residual heights and reflecting ‘Brs Kurumi’ ability to adjust its growth and sward structure to sustain adequate forage production, a high leaf proportion, and nutritive value.