A  FIELD experiment was carried out in 2014 growing season in Hehia, El-Sharkia Governorate, Egypt to asses application of 95 kg K ha^-1 applied to maize (Zea mays) as potassium sulphate (KS) or  potassium  feldspar (KS) combined with potassium dissolving bacteria (i.e., silicate dissolving bacteria "SDB", Bacillus circullans) individually or in  different combination ratios. 50% KS + 50% KF  gave the highest values of  height of maize plants, leaf area, ear length, ear diameter, ears yield, stover and grains dry weight, NPK-uptake, protein content and biological yield. The treatments of 25% KS + 75% KF and control gave the lowest among the treatments receiving K. The application of  50% KS + 50% KF  gave increases in  stover and grains dry weight which ranged from 40 – 51 % and 87 – 118 %, respectively. The treatment of (K3)  at 45, 90 and 180 days gave the highest value of  soil available potassium (295, 375 and 247 mg kg^-1, respectively), while the lowest ones (63, 58 and 51 mg kg^-1 , respectively) were found with untreated soil.