Two field trials were conducted on potato cv. Spunta, in private farm at Kafr Meet Faris, Dakahlia Governorate, during 2018 and 2019 seasons to study the effect of NPK levels (100%, 75% and 50% NPK of the recommended rate) either single or in combination with some applications of fulvic acid and biochar treatments (untreated, fulvic acid at 10 kg/fed,  biochar at 5 m³/fed and fulvic acid at 10 kg/fed + biochar at 5 m³/fed)) on plant growth, yield and its quality as well as chemical constituents of plant foliage and tubers. Results showed that the most studied characteristics of potato plants were significantly increased with increasing NPK-level up to 100%. Besides, the most interesting observation was the increasing of the yield and its components by 100% NPK level. Moreover, this treatment significantly increased concentration of all chemical constituents in foliage and tubers comparing with those of the other treatments. Application of fulvic acid and biochar treatments caused significant increases in the most studied parameters as comparing with the control treatment. The highest record data was obtained from application of fulvic acid + biochar. The combined treatments of NPK levels and fulvic acid and biochar treatments were generally more effective on the most studied parameters than with single ones. The best results were obtained by 75 % NPK level with fulvic acid + biochar treatment. Therefore, this treatment could be recommended for raising potato yield and improving tuber quality under similar conditions to this work.