The present study was carried out at the Experimental Farm, Faculty of Agriculture, Menoufia University, Shebin El-Kom, Egypt during 2019 and 2020 summer seasons to study the influence of intercropping three summer grass forage crops, i.e. pearl millet, sudan grass  and teosinte at 100% from their recommended seeding rate with maize at three densities of maize, i.e. 50, 75 and 100% of the recommended plant density (24000 plants/fed) on their productivity and quality as well as the land use efficiency and the competitive relationships. The treatments were arranged in a randomized complete blocks design with four replications. The obtained results could be summarized as follows:
1-Intercropping forage crops with maize decreased most growth characters (No. of shoots/m², total chlorophyll, No. of leaves /shoot, leaf area/shoot and total dry weight/shoot, forage yield (fresh and dry forage yields/fed), chemical composition (protein% and ash %) as well as nutritive value (digestible protein “DP" % and total digestible nutrients “TDN" %), but increased plant height and fiber % of forage crops compared to their sole croppings. Sudan grass surpassed other forage crops in plant height and fiber%, while millet crop recorded the highest values of No. of shoots/m²,total dry weight/shoot, fresh and dry forage yields/fed. Teosinte crop exceeded millet and sudan grass in total chlorophyll, No. of leaves/shoot and leaf area/shoot as well as chemical composition (protein % and ash %) and nutritive values (DP% and TDN %). Increasing plant density of maize from 50% to 100% intercropped with forage crops increased plant height of forage crops, but caused a reduction in growth characters, forage yield as well as nutritive values of forage crops