A field experiment was carried out at experimental farm at El-Kassasin, Horticulture Station,
Agricultural Research Center (ARC), Ismallia Governorate, Egypt during summer season of 2016 and 2017 to
evaluate the potentiality effect of humic acid and/or biofertilizers combined with different rates from mineral
fertilization to reduce dependence on mineral fertilizers,and improve growth and productivity of Jerusalem
artichoke plants (Helianthus tuberosus L. cv. Fuseau). The highest values of growth parameters i.e., plant height,
number of main stems, number of branches, fresh and dry weight of shoots were exhibited with humic acid +
biofertilizers treatment combined with 75% NPK in both seasons. This treatment also indicated the maximum
NPK percentage values and uptake of these elements in shoots in both seasons. Still this treatment 75% NPK + H
+ BF was superior in tubers yield as it gave 25.001 and 25.429 ton/fed and the relative increase over control
reached to 2.57 and 1.69% in both seasons, respectively. Concerning the tubers quality represented by total
carbohydrates and inulin, the application of humic acid with biological fertilization combined with 75% NPK
increased the tubers 'content of inulin, which reached 2.77 and 2.798 ton/ fed in both seasons, respectively, the
relutive increase over the control by 4.33 and 4.47 %, respectively. While the tubers contentof carbohydrate was
not affected by addition H and BF with 75% NPK compared with control. The obtained results revealed that the
total microbial count and yeast count in the rhizospheric area were higher with the treatment 75% NPK + H + BF
compared to control, while the maximum count of Azotobacter sp. was attained with treatment 50% NPK + H +
BF in both seasons. The mixture treatment (75% NPK + H + BF) was still the superior one where it gave the
highest enzymes activity represented in nitrogenase (µmole C2H4/g rhizosphere/h), Dehydrogenase (µg TPF/g
dry soil/day) and acid and alkaline phosphatase (µg/g dry soil). Generally, these results undoubtedly confirm that
humic acid dual with bio-fertilizers could saving the use of chemical fertilizers and consequently improve the
quality and quantity of plants and produce more save foods at the same time