Foliar fertilization is a complementary alternative to soil fertilization, as it allows the supply of nutrients in the period of maximum demand for the crop and avoids exposure to nutrient loss processes that occur in the soil. Nitrogen is one of the nutrients most required by sugarcane and can be absorbed by leaves in nitric (NO3-), amidic (NH2) and ammoniacal (NH4+) forms. The micronutrients nickel (Ni) and molybdenum (Mo) can facilitate the increase in the assimilation of N supplied via the leaves through the activation of the enzymes urease (UR) and nitrate reductase (NR), respectively. Both promote increased N assimilation and conversion into crop biomass. The objective of the study was to evaluate the effect of foliar fertilization with different forms of N, combined with Ni and Mo, in enhancing foliar N metabolism and sugarcane growth. The experiment was carried out in cane plants with the RB867515 variety cultivated in lysimeters for a period of 202 days. The experimental design was randomized blocks, with 8 treatments and 3 replications, totaling 24 experimental plots. The treatments consisted of foliar application of Ni, Mo and N (NO3-, NH4+ and NH2), with the equivalent of 2 kg ha-1 of N, 6 g ha-1 of Ni, 50 g ha-1 of Mo, in the combinations N + Ni, N + Mo and N + Ni + Mo and the control treatment (water + dispersant). The solutions were manually sprayed on the F+1, F+2 and F+3 leaves, at the stage of maximum vegetative growth of the crop, at 105 days after planting (DAP). On the third and eleventh days after spraying (DAPF), the middle third of the leaves that received the solution was collected for evaluation of the activity of the nitrogen metabolism enzymes UR and RN, as well as the determination of the levels of total N, NH4+, NO3-, Ni and Mo. At the end of the evaluation cycle, the biometric parameters were measured: plant height (from the base to the insertion of the leaf +1), average stem diameter and plant dry biomass. The length and the internode diameter of the leaves that received the application were also measured. The data obtained were subjected to the Shapiro-Wilk normality test (p <0.05) and homogeneity of variances by the Levene test (p <0.05) and transformed when necessary. Normal and homoscedastic data were submitted to analysis of variance (p <0.05) and means compared using the Scott-knott test. (p<0.05). In the metabolism of N, only the RN showed a difference and it increased with the application of N on the leaf after 11 days. The Mo content in the leaves increased at three DAA when the solution contained this nutrient, which demonstrates that Mo is absorbed in a short period, but without effect on N metabolism. nutritional content of N from sugarcane, since there was no difference in the NO3-, NH4+ and total N contents in the leaves and in the plant after applying the solutions, keeping the contents always below the values considered adequate. The low response in metabolism and no effects on nutrition did not promote gains in plant growth and dry biomass production.