This research was accomplished with the objective of evaluating the nutritional efficiency of the use of serum of cow milk in substitution to the nutrient solution in hydroponic cultivation of forage corn. The experiment was carried out under greenhouse conditions in a completely randomized design with six treatments and five replications. The conventional nutrient solution was used as the control. The other treatments were distributed in different levels (20, 40, 60, 80 and 100%) of milk serum dilution in drinking water. Corn plants were harvested 15 days after the germination, separating biomass of shoots from biomass of the substrate with the roots. The mass of fresh and dry matter, the macro (N, P, K, Ca, Mg and S) and micronutrient (Fe, Cu, Zn and Mn) contents were evaluated, besides the elements in toxic levels (Na and Cl), in both shoots and substrate plus roots masses. Increase in milk serum concentration promoted reduction of hydroponic forage yield, increment in N, S and Zn, stability of K, reduction of Ca and Mg, and no effect on P, Fe and Cu contents in shoots. In root there was increase in P, K, Ca, Mg, S and Cu.
Zea mays L.; hydroponics; biofertilizer; residue use
