It is necessary to apply organic matter to improve the productivity of arid and semi-arid soils, which naturally have 0.1 to 1.0% organic matter. Composting is a continuous process during which microorganisms transform organic matters into more stable forms having proper odor, optimized pH, high level of elements such as N, P, and K; therefore, compost is considered the best organic fertilizer. However, compost needs to be improved and enriched due to its long processing time and its deficiency in some nutrients. Therefore, in order to study the effects of compost and vermicompost enriched with phlogopite and sepiolite on physico-chemical properties of plant growth medium a pot experiment was conducted at the greenhouse of the Soilless Research Center, Isfahan University of Technology, using a completely randomized design with factorial arrangement with 20 treatments and 3 replicates. Treatments included time periods of composting (3 and 6 months), presence or absence of earthworm, the type and level of enriching silicate (20 and 40% of phlogopite and 15 and 30% sepiolite) and presence or absence of plant. Fresh cow manure devoid of soil particles were taken from Lavark Research Farm, Isfahan University of Technology. It was then mixed with or without earthworm to produce vermicompost and compost, respectively, and enriched with or without either phlogopite or sepiolite. Triplicates pots were filled with a mixture of 50 grams of each treatment and 850 grams of quartz sand. After planting barley seeds and the germination and establishment of seedlings, pots were irrigated with distilled water and/ or one of the two nutrient solutions (Mg-free nutrient solution for the sepiolite containing pots and K-free nutrient solution for the phlogopite containing ones) for a period of 3 months and also urea was applied to all the pots as needed. At the end of the 3-month growing period, the shoot was harvested and collected and the root was also separated from the growth medium and collected. The weight of shoot and root as well as the total weight, relative turgidity, the amount of total and available Fe, Mg, and K were also determined. Paticle density, bulk density and total porosity were measured on disturbed samples. Water content at field capacity (FC) was measured using a sand box and water content at permanent wilting point (PWP) using a sand kaolin box. Saturated hydraulic conductivity was measured in the pots. Water repellency was measured using the water drop penetration time (WDPT) method. Also, organic matter, EC, pH, and the total and available Fe, Mg, and K were determined in the growth media. Results indicated that the application of compost and vermicompost enriched with either phlogopite or sepiolite not only did not improve the yield of barley, but also reduced the yield as compared to the control As the level of added sepiolite increased, the yield decreased substantially mainly due to the reduction of porosity and water infiltration and aeration problems. Enrichment with silicates caused significant differences in plant relative water content, growth medium particle density, bulk density, total porosity, FC, PWP, available water, saturated hydraulic conductivity, water repellency, organic matter, pH, and the level of total and available Mg and K at 5% probability level. Enrichment treatments did not significantly influence electrical conductivity. Phlogopite had positive influence on plant growth as compared to sepiolite but was not able to create the level of yield obtained in the control treatment. It seems that the enrichment of compost and vermicompost with lower level of phlogopite may increase the plant yield in long term. However, we need to be careful to enrich these materials with sepiolite even at the low levels. Keywords: Soil productivity, Organic matter, Enrichment, Silicate minerals, Barley, Physical properties, Chemical properties, Biomass.