Evaluation of Potassium Quantity-Intensity in some Soils of El-Dakhla Oasis, New Valley, Egypt

Mahdy H. Hamed, Abu El-Eyuoon Abu Zied Amin

The current research was carried out in 2016 to evaluate potassium Quantity-Intensity parameters and the relation of these parameters to the characteristics of some agricultural soils of El-Dakhla Oasis, New Valley, Egypt. Six surface soil samples (0-30 cm) were collected from different sites in El-Dakhla Oasis. The values of equilibrium activity ratio of potassium (ARko) ranged between 0.0071 (soil 3) to 0.0320 (mol/L)1/2(sample no. 1). The labile K (-ΔK0) values also, varied from 0.020 (sample no. 4) to 0.412 (cmol/kg soil (sample no.1).The values of the potassium potential buffering capacity (PBCK) of soil ranged from 0.964 to 12.86 [(Cmol kg-1/(mol L-1)0.5]. Generally, the highest value of ARko, ΔK0, PBCK parameters were related in soil sample no. 1[(0.032 (mol/l)0.5, 0.412 cmol/kg, and 12.86 [(cmol kg-1/(mol L-1)0.5], respectively. The ARko was a negatively significant correlated with exchangeable potassium (r=-0.822), Organic matter (-0.633) and available K (-0.444). A positive highly significant correlation was obtained between the labile K (-ΔK0)and both exchangeable Ca and Mg (r=0.936 and 0.941, respectively). The PBCK showed a positive significant correlation with clay content, available K and cation exchangeable capacity (CEC), and negative  significant correlations with soil pH (r=-0.795) and CaCO3 (r=-0.633). 

Key words: Quantity/Intensity parameters, Potassium kinetics, El-Dakhla Oasis