Sorghum cultivation is one of the main options for grain and forage production in water deficit areas. The use of organomineral is an innovative alternative in grain production, reducing production costs and optimizing natural and economic resources. This study evaluated biochemical parameters (net photosynthesis and stomatal conduction) in the productivity of grain sorghum with different sources of organominerals (06-30-00 and 09-46-00). The design was randomized blocks with a total of 28 replications and 4 blocks at the Experimental Campus of ILES/ULBRA, Itumbiara, GO. It is concluded that organomineral “A” promotes greater performance in stomatal conductance and photosynthetic rate during the vegetative stage of sorghum, with consequent formation of plant architecture to support the reproductive stage of the analyzed cultivar.