Chemical composition and methane yield of sorghum cultivars with contrasting row spacing

A two year study was carried out to evaluate the impact of row spacing and cultivar on biomass yield, chemical composition and biogas yield. The experiments were designed as RCBD under split plot arrangement with two factors: row spacing in main plot and cultivars in sub plots with four replications. Three row spacing (75 cm. 37.5 cm, double row 75 cm apart and 10-15 cm with in row) and two cultivars Goliath and Bovital were used during the experimental year 2008, while same row spacing and five cultivars Goliath, Bovital, Aron, Rona 1 and Akklimat were included in 2009. Biomass yield (DM t ha(-1)) was similar among all three row spacing; however cv. Goliath (Sorghum bicolor x S. bicolor) reached higher DM yield in comparison with other tested cultivars. Cv. Akklimat (S. bicolor x Sorghum sudanense) Led to greater protein concentration within the five cultivars evaluated in present study. In 2009, cv. Aron with row spacing of 37.5 cm led to markedly higher sugar concentration followed by 75 cm (DR) will same cultivar. The concentration of neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL) and ash concentration were lowest in cv. Rona 1 (S. bicolor) followed by cv. Aron (S. bicolor). Row spacing had same level of biogas yield, methane yield and methane concentration c f sorghum. Although cv. Rona 1 reached higher specific methane yield per kg VS but it was overcompensated by cv. Goliath due to higher dry matter yield ha(-1). In addition, interaction was also found between cultivars and row spacing with respect to biogas as well as methane yield ha(-1) in 2009. However sorghum is a short duration crop with shorter plant development than maize. Hence, it can be introduced in crop rotations as the following crop after winter forage cereals harvested in spring. Another advantage could be that sorghum can replace maize to reach higher diversity in cropping systems of Germany. (C) 2011 Elsevier B.V. All rights reserved.