The current study was executed in a newly reclaimed sandy soil at Ali Moubark farm, South Tahrir Research Station, Horticulture Research Institute, during the two successive growing seasons of 2018-2019, to rationalizing mineral potassium consumption from natural sources such as feldspar rock and potassium-releasing bacteria and its impact on quality, production and storage capacity of sweet potato cv. Abees. A Randomized Complete Block Design with four replications was used. Treatments included six levels of potassium 25, 50 and 75% of recommended dose of potassium sulphate (48% K2O) plus feldspar rock (10.6% K2O) with inoculation by potassium releasing bacteria i.e. Bacillus circulans as well as 100% recommended dose of potassium sulphate, 100% recommended dose of feldspar rock and 100% recommended dose of feldspar rock with inoculation by potassium dissolving bacteria.
Results conclude that adding 50% from the recommended dose of potassium sulphate plus 50% feldspar rock with inoculation by Bacillus circulans bacteria recorded the higest values of vegetative growth (plant length per plant, number of branches per plant, leaf area and chlorophyll content), total yield, yield properties (tuber root diameter, tuber root weight, tuber root length and tuber root dry matter) and chemical centent (leaves potassium %, total carbohydrate % and tuber roots potassium %).