A field experiment was carried out during the two successive winter seasons of 2016 and 2017 in a clayey textured soil located at Sakha Agricultural Research Station farm, Kafr El-Sheikh Governorate to study effect of humate substances (HS) as complexes agent on NH4+, K+, Ca++ and Mg++ antagonisms on Potatoes crop (Solanum tuberosum, L. - c.v. spunta). A split plot design was used with three replicates. The main plots were assigned with three application methods: without humate substances, humate substances fertilizer coating and soil addition of humate substances with irrigation water . The sub plots were assigned with five fertilization treatments N, NK, NKCa, NKMg and NKCaMg. The results showed that soil addition of humate substances with NKCaMg treatment had a significant effect on plant growth parameters in leaves at 90 days age and yield components. The highest values of tubers yield, dry matter % of tuber, protein %, starch %, N, P, Mg-content kg.fed-1 were obtained with soil addition of humate substances +NKCaMg. The highest K-content kg.fed-1 was obtained with soil addition of HS+NK treatment, the highest Ca-content kg.fed-1 was observed with soil addition of HS+NKCa treatment. It could be concluded that humate substances fertilizer coating by humate substances or soil addition of humate substances could help in decrease antagonism process to improve plants growth and increase tubers yield and their quality under this conditions as well as increase nutrient efficiency of potato.