Abstract
Sole and intercropping of sweet sorghum (Sorghum bicolor, L.) and legumes (Vigna radiate, Glycine max) were assessed to evaluate an appropriate cropping system for maximizing bioethanol production. Experiments conducted in dry season of 2009/10 and 2010/11 using the treatments, included two legumes (L1: mungbean; L2: soybean), two planting patterns (P1: alternate single row; P2: alternate double row) and two times of seeding (T1: simultaneous; T2: staggered). Eight intercropping systems (L1P1T1…L2P2T2) were compared with sole crop of sweet sorghum for performance indicator parameters i.e. dry weights and contents of soluble sugar, starch, cellulose, and hemi-cellulose of plant parts of tested crops, and first and second generation bioethanol yields of crops and cropping systems. It was noted that stand of sweet sorghum in intercropping characterized with L2, P1 and T2 yielded dry weights of leaf, stalk and grain, and bioethanol yielding chemical substances at par with its sole crop. Similarly, dry weights and chemical substances of intercropped legumes were minimally reduced in intercropping with T2 compared to their sole cropping. Resultantly, first generation, second generation and total bioethanol yields of intercropping system of L2P1T2 (8659-8991, 8321-8773, 16980-17764 Lha-1, respectively) was observed to be significantly (P < 0.05) greater compared to sole crop (7846-8184, 6876-7240, 14723-15425 Lha-1, respectively) of sweet sorghum due to contribution and reduced competition of intercrop soybean in both the years.
