To evaluate the forage production of sorghum/cowpea intercropping, a field experiment was conducted at Tarbiat Modares University in 2003. Experiment was carried out in a split plot design based on randomized complete blocks with 4 replications. Plant density with 3 levels [ Low(D1), Mean(D2) and High(D3) respecting 10, 13.3 and 20 plant/m2 for Sorghum bicolor cv. Speedfeed and 13.3, 20 and 40 plant/m2 for Vigna unguiculata cv. Mashahd] was arranged in main plots and 5 mixing ratios [(M1)=100/0, (M2)=75/25, (M3)= 50/50, (M4) =25/75 and (M5)=0/100 percents for sorghum/cowpea) were arranged in subplots. Quantitative attributes such as dry weights of two crops, number of cowpea branches and sorghum tillers were measured in two sampling during growth season. Special indices for evaluating intercrop performances were calculated. Results showed that plant density has no significant effect on almost all traits, while mixing ratio influenced them significantly (p<0.01). M2 mixing ratio,75/25 (sorghum/cowpea) by producing 17.31 t.ha-1 forage dry weight was placed in the superior group. According to performance indices of intercropping the D1M2 treatment with high relative crowding coefficient (RCC=2.54) and high land equivalent ratio (LER=1.19) was the most efficient intercrop treatment for forage dry yield.
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