Two field experiments were preformed at the Experimental Farm of Sids Agricultural Reseasrch Station, ARC, Beni-Suef Governorate, Egypt to study the possibility of using feldspar as potassium source along with some bio-stimulants namely, silicate dissolving bacteria (SDB), humic acids and farmyard manure and its effect on cotton productivity and soil properties after harvest. The results indicate that added 400 kg feldspar/feddan, 10 kg humic acid or 10 m³ FYM/feddan improved plant height, number of fruiting branches/plant, number of open bolls/plant, boll weight, seed cotton yield, earliness%, seed index and leaf chemical contents, i.e.; N, P and K%, chlorophyll A and/or B as well as soil available N and K. Feldspar increased the soil available N and K, while FYM or humic acid improved soil pH, O.M, soil available N, P and K. On the other hand, soil salinity was increased as FYM application. The results of the interaction between treatments show that the best results were found when cotton plants were treated with 400 kg feldspar/feddan + 10 m³ FYM/feddan or 10 kg humic acid/feddan in combined with silicate dissolving bacteria. Furthermore, the effect of SDB on cotton productivity is more pronounced when combined with feldspar, FYM or humic acids