Effects of Row Spacing and Tropical Grass Intercropping on Biomass Sorghum Yield and Silage Quality

This study aimed to determine the optimal combination of forage grass and row spacing to maximize the balance between sorghum silage yield and quality in a simultaneous sowing system for integrated crop-livestock production. The experiment evaluated three cropping systems: biomass sorghum (Sorghum bicolor (L.) Moench) in monoculture, and intercropped with Urochloa brizantha cv. Marandu and Megathyrsus maximus cv. BRS Zuri. These systems were tested under two row spacings: 45 cm and 90 cm. The field trial was conducted in Vicentina, Mato Grosso do Sul State, Brazil, using a randomized complete block design in a 3 × 2 factorial arrangement with four replications. Dry matter production, fermentative parameters, and chemical composition were measured. The 45 cm spacing provided higher productivity (23.1 t/ha of TDMY), while the intercropping with Zuri grass showed lower levels of NDF (73.46%) and ADF (49.61%), indicating better nutritional quality. The silages exhibited ideal pH (4.0–4.1) and low levels of butyric acid (<0.33%), with higher total digestible nutrients (TDN) (54.33%) at the 90 cm spacing. The Sorghum + Zuri (ZS) intercropping at the narrower spacing (45 cm) is viable for quality silage production, showing a better balance between overall chemical quality and biomass production.