an evaluation of forage yield in sole and intercropping of sorghum and alfalfa and its effect on weed biomass

to evaluate the effect of intercropping of sorghum and alfalfa on forage yield and on weed biomass production, different proportions of sorghum and alfalfa intercropping system comprised of 50% - 50%, 25% - 75% and 75%-25%, along with sole cultures of sorghum, and of alfalfa were arranged as split plots in time, while a complete plot design with three replications being used to analyze the data. the experiment ran for three years during which no weed control measure applied. alfalfa 25% - sorghum 75% was the highest forage producing treatment across the three years of the experiment while during the second year of the experiment alfalfa sole culture produced significantly more forage as compared to either of the intercropped treatments and sorghum sole culture, these in turn being followed by alfalfa 75% - sorghum 25% intercropping treatments. sorghum sole culture was the least forage producing treatment across all the experimental period (three years). in the first year of the experiment, weed populations dominated alfalfa sole culture and other treatments with a higher proportion of alfalfa in the intercropping system. as the proportion of sorghum in intercropping system increased, the population of weed significantly declined. the population of weed followed a declining trend as the period of the experiment proceeded to the second and the third year in treatments with a higher proportion of alfalfa. the biomass of weeds in the second year of the experiment in the higher proportion of sorghum (>50% sorghum) treatments was highest at the first harvest. however, there was a significant declining trend observed at the forth and fifth harvests.