Loess processed material (LPM) was produced as a substitute for silicon, clay and minerals, and applied to tomato and cucumber cultivation. LPM was produced by using a NaOH addition ratio of 30%, a reaction temperature of 1,200 oC, a reaction time of 1 h, and an alumina ball diameter of 10 mm. Treatment with a 200-fold diluted LPM solution resulted in respective increase of 7.8% and 8.3% in the weight and quantity of the tomato fruit, and a 31.7% increase in the quantity of cucumber fruit produced, when compared to the control. On the other hand, commercial silicon fertilizer (CSF), with a price that is estimated to be four times that of LPM, did not significantly increase the yield of tomato or cucumber in terms of weight or quantity. Thus, it is suggested that LPM may be used as a potential complex silicon fertilizer.