about 992 ug/gm in the surface 2 inches to 1,308 ug/gm in the 4- to 6- 
inch layer. The highest extractable cation concentration was in the 
4- to 6-inch soil layer. 
In February, concentration of the four extractable cations varied 
between zones (Table 13). Maximum Ca concentration was in the upper 
zone. The concentration decreased in the middle zone with a slight 
increase in the lower. This same trend was reflected by K and Mg, but 
Mg was present in larger quantities than either Ca or K. Sodium con- 
centration decreased from a high of about 1,860 ug/gm in the upper zone 
to approximately 620 u.g/gm in the lower zone. 
Soil pH in May, by depth, was similar to that recorded in February 
(Tables 12 and 14), with only slight differences between depths. By 
zones, sO0il pH was slightly lower in May than February (Tables 12 and 
15). However, the values were still near neutral. 
Calcium concentration decreased with an increase in depth from the 
soil surface to 6 inches (Table 14). The concentration, in general, was 
twofold higher in May than in February. Potassium concentration was 
uniform throughout the depth sampled and was lower than Ca, but had 
increased slightly from February. In general, Mg fluctuated only 
slightly with soil depth, but the concentration at all depths was con- 
Siderably higher than in February. The maximum Na concentration 
(1,842 ug gm ) occurred in the 2-to 4-inch soil layer. This was only 
slightly higher than in the surface soil. A decrease of over 450 ug/gm 
occurred between the 2- to 4- and 4- to 6-inch layers. Sodium was the 
dominant extractable cation at all depths and occurred in higher con- 
centrations than in February. 
The four extractable cations varied in concentrations between zones 
in May (Table 15). Maximum Ca concentration was in the lower zone with 
the minimum in the middle. The trend exhibited an increase in K from 
the upper to the lower zones. This was a reversal of the trend exhibi- 
ted in February. Magnesium content was highest (412 ug/gm) in soil of 
the lower zone while the minimum (279 yg/gm) occurred in the middle 
zone. This trend was a reversal of that exhibited in February. Sodium 
concentration was high in the upper and middle zones and declined in 
the lower. In February the high sodium concentration was restricted 
to the upper zone. In general, extractable cations occurred in larger 
quantities in May than in February. 
Soil pH changed only slightly between February and May by depth 
and zones (Tables 16 and 17). Extractable cations did fluctuate by 
date, depth, and zone. All cations occurred in larger concentrations 
in May than in February at all three soil depths and were similar or 
greater in the three zones. This probably was a reflection of low 
rainfall and increased water salinity during the period before soil 
sampling in May. 
38 
