A MSc THESIS SUBMITTED TO THE DEPARTMENT OF ANIMAL SCIENCE SCHOOL OF POST GRADUATE STUDIES ARBAMINCH

Abstract

The study aimed to assess the effect of intercropping lablab and forage sorghum on agronomic performance, chemical composition and economic feasibility of the main and component crops in Arba Minch Zuria district. The study was conducted with a 4×2 factorial arrangement in a randomized complete block design (RCBD) with three replications. The experiment included two rates of fertilizers (0 kg/ha and 100 kg/ha) and four intercropping ratios (sole lablab, sole forage sorghum, intercrops of forage sorghum-lablab in 1:1 alternative rows, and intercrops of forage sorghum-lablab in 2:1 alternative rows). All parameters were analyzed by using analysis of variance (ANOVA) with the general linear model procedure of statistical analysis system (SAS). Forage sorghum with a 1:1 intercropping ratio and 100 kg/ha nitrogen, phosphorus, sulfur, and boron (NPSB) fertilizer showed significant (P <0.05) increases in plant height (262), leaf number (14.1), internode length (7.3), fresh biomass yield (33.3 t/ha), and dry biomass yield (6.01 t/ha). Similarly sole lablab cropping with 100 kg/ha NPSB fertilizer application was also significantly (P<0.05) increased fresh biomass yield (22.49t/ha), dry biomass yield (3.64t/ha),leaf number (140.1),branch number (7.5),total nodules (36.2),effective nodules (23.8),days to start flowering (84) and days to 50% flowering (98). Intercropping forage sorghum with lablab had an advantage of resource utilization in terms of land equivalent ratio (LER) 53% to 84%. Fertilizer application and forage sorghum intercropping with lablab have a significant (P<0.05) impact on percentage dry matter, organic matter, crude protein, ether extract, neutral detergent fiber, acid detergent fiber and hemicellulose but not on percentage ash, lignin and cellulose (P>0.05). The sole lablab with 100 kg/ha NPSB had the highest crude protein (21.9%) and ether extract (3%), the lowest percentage neutral detergent fiber (32.1%) and acid detergent fiber (26.1%) while the sole forage sorghum without fertilizer had the lowest values of crude protein (5.13%) and ether extract (1%) and the highest percentages of neutral detergent fiber (64.4), hemicellulose (22.13), and lignin (10.45). The study concluded that that intercropping and blended fertilizer application improves the forage quality, biomass yield and marginal rate of return (MRR) as higher as 25.2% in a 1:1 cropping pattern which was better than sole cropping.