PANOCHE GROUP 



"-BASIN GROUP 



"x:. 



SORRENTO GROUP 



JAN FEB MAR APR WAY JUN JUL AUG SEP OCT NOV DEC 

 1967- 68 

 FIGURE 13-SEASONAL VARIATION OF NITROGEN CONCENTRATIONS 

 IN DIFFERENT GROUPINGS OF SOILS 



Figure 13 compares the monthly average nitrogen concentra- 

 tions in drainage composited from three groups of soil 

 series: the Panoche group (Panoche, Panhill and Lost Hills); 

 the Sorrento group (Sorrento, Rincon, and Ambrose); and the 

 Basin group (Oxalis, Lethent, and Tulare). The Panoche 

 group occurs in the Gustine-Mendota area, and the Sorrento 

 group occurs in the Byron- 

 Westley area. The Basin 

 group, which is not a 

 family grouping, represents 

 the composited drainage 

 from basin and basin rim 

 soil series vjithin all the 

 major tiled areas. It is 

 shown to illustrate the 

 seasonal variation in 

 drainage having low 

 nitrogen concentrations 

 and for comparison to the 

 family groups . Although 

 the Panoche and Sorrento 

 family groups are similsir 

 in texture, soil develop- 

 ment, and other factors, 

 they do differ genetically. 

 The greatest seasonal vari- 

 ation of nitrogen occurred 

 in the drainage from the 

 Panoche grouping. 



The yield of nitrogen 

 (pounds per acre per month) 

 from tile systems within 

 the soil groupings is 

 presented in Figure l4 . 

 The greatest nitrogen 



yield occurred in drainage composited from the Panoche group; 

 peak yield occurred in March, which was possibly the result 

 of early leaching during preirrigation. The influence of 

 relatively high discharge along with low nitrogen concentra- 

 tions is shown in the contrasting yield of nitrogen between 

 the Sorrento group and that of the Basin group. Several 

 tile systems having the highest discharges were associated 

 with the Sorrento and related soils . 



FEB MAR APR MAY 



AUG SEP OCT NOV DEC 



JUN JUL 

 1967 • 68 

 nOURE 14-SEASONAL DISTRIBUTION OF NITROGEN 

 IN DIFFERENT GROUPINGS OF SOILS 



Total Dissolved Solids 



Table 1? also shows that average concentrations of total 

 dissolved solids were the highest in drainage from tile 

 systems in the Tulare (basin position) and Willows (basin 

 rim position) soil series, which are among the lowest in 

 nitrogen. 



65 



