Two investigations were carried out in the open field to study the effects of some soil stimulating supplements, i.e., humic and fulvic acids, zeolite, chicken manure as well as compost on vegetative growth, chemical contents and productivity of sweet pepper plants under drip irrigation system. Results indicated that all applied soil substances significantly enhanced vegetative growth parameters, chemical constituents, endogenous phyto-hormones of leaves, yield and fruit quality compared to the control in both growing seasons of study. Soil applications of either zeolite or compost are the best treatments in enhancing most of the aforementioned parameters. Additionally, our results undoubtedly confirm that the application of zeolite or compost could decrease chemical fertilizers through improving the efficiency of both fertilizers and irrigation water which in turn increase vegetable crops production, minimize economic costs as well as limit environmental contamination.