Effect of Cutting Stage on Forage Yield and Quality of Nilegrass and Pangolagrass

Abstract

Nilegrass (Acroceras macrum) is a C3 perennial forage grass while pangolagrass (Digitaria decumbens) is a C4 species. The objectives of this study were to determine the effects of different cutting stages on forage yield and quality of nilegrass and pangolagrass. Four cutting stages, i.e., 4, 6, 8 and 10 weeks after the previous cutting, were used in the experiment. Both fresh and dry weights of nilegrass and pangolagrass increased with later cutting stages in the first 3 years. However, the forage yields of these two species cut after 10 weeks were lower than those cut after 8 weeks in the 4(superscript th) year. Nilegrass produced significantly higher forage yield than pangolagrass did for all cutting stages except cutting after 6 weeks. The crude protein contents of both nilegrass and pangolagrass decreased with the delayed cutting stages, while those of neutral detergent fiber (NDF) and acid detergent fiber (ADF) increased with later cutting stages. No significant difference was observed for the contents of water soluble carbohydrate (WSC) of nilegrass among cutting stages. However, WSC of pangolagrass increased with the advancement of cutting stages. Pangolagrass had higher content of WSC than nilegrass did for all the cutting stages. The pH value of the soil increased with cutting stages in forage land cultivated with either nilegrass or angolagrass. Results suggest that nilegrass harvested between 6 and 8 weeks may produce higher forage yield and quality.