EFFECT OF POTASSIUM SOURCES AND SOIL AMENDMENTS WITH SILICATE DISSOLVING BACTERIA ON AVAILABILITY OF POTASSIUM IN CLAYEY SOIL CULTIVATED WITH WHEAT PLANTS.

A pot experiment was conducted under greenhouse condition at the Experimental Farm, Faculty of Agriculture, Zagazig University, Egypt. The experiment aimed to study the effect of different potassium sources (potassium sulphate and potassium feldspar) at the recommended rate (40 mg K kg-1) either single or in combination with soil amendments i.e., farmyard manure (FYM) and sulfur (S) with or without silicate dissolving bacteria (SDB) on yield and nutrients uptake by wheat through the investigated clayey soil. Soil were taken from the surface layers (0-30 cm) from Hehia District, Sharkia Governorate, Egypt. Application of K-sulphate or K-feldspar as individual application or combined with different soil amendments under SDB gave increase in straw and grain yield, potassium uptake, biological yield, 1000 grain weight and protein content of wheat plants compared to untreated soil. The highest value for each of yield, K-uptake and available K was found in clayey soil treated with K-sulphate combined with FYM plus S in the presences of SDB, while the lowest ones were obtained with untreated soils in absence of soil amendments and SDB. Application of Ksulphate showed greater value in each of yield, protein content, K-uptake by wheat plants and soil available potassium than K-feldspar. Application of SDB to K-sulphate or K-feldspar increased yield, protein content, K-uptake of wheat and available potassium compared to the untreated ones. [ABSTRACT FROM AUTHOR]