Part 1) measurements consisted of redox potentials, pH (1:1 paste), temperatures, moisture 



contents, bulk densities, depth to free water, and estimations of root and coarse skeleton 

 contents, texture, and color on each 15-cm by 5-cm core segment collected. 



Part 2) measurements consisted of electrical conductivities, pH,and concentrations of Al, 

 total Fe, ferrous Fe, Mn, NHj-N, NO3-N, NOj-N, PO4, Si, SO4, Ca Mg, Na, and K in the soil solu- 

 tion extracted fromeach core segment. Measurements of electrical conduct ivity.pH, and concen- 

 trations of Ca, Mg, Na and K in soil solution are completed. 



The tesseras will provide base-line soil data to be used for coordination of all project studies 

 and for evaluation of soil variability at the study site. Measurements conducted on these samples 

 were total C, total N, extractable P, pH, exchangeable acidity, exchangeable bases (Ca, Mg, Na, 

 K), bulk density, particle-size distribution, texture and colors. At this time, total C and N deter- 

 minations have been completed on aU 249 samples collected. 



Part 5) of the studies consisted of collecting soil core samples from Schultz's gasline plots 

 for chemical analyses (Fig. 2 location 12). The main purpose of this part of the study was to 

 provide comparability between previous years' studies and the present studies with regard to nutrient 

 cycling. Sampling procedures there were similar to those of the IBP intensively studied sites to 

 Insure maximum comparability between all sites. Samples were collected in late June, early August, 

 and late August. 



Much remains to be done on laboratory analyses, data reduction, and processing. A compre- 

 hensive prc^ram of factor analysis has been initiated on the data. In the meantime, some results 

 of the studies can be discussed, although precautions must be taken to ensure that initial inter- 

 pretations are not construed to be final or, for that matter, even necessarily correct. 



No Mn, HjS, or NOj-N was detected In any of the soil solution extracts. Only in an occasional 

 extract was any NO3-N or SO4 detected; and at this time the significance, if any, of these findings 

 is not apparent. The absence of Mn, HjS, and NOj-N and the' occasional occurrence of NO3-N and 

 SO, in the soil solution, if true, pose some interesting questions that will hopefully be answered in 

 the near future. It is a certainty that microbiological populations and activities, as well as reduc- 

 tion potentials of the soil solution, will have important bearings on answers to these questions. 



Concentrations of Al, Fe+', Fe+', NHj-N, PO4, Ca, Mg, K, Na and Si inthe soil solution 

 generally increased with depth (Table XXII). This was also true of soil pH. The pH of the soil 

 solution, on the other hand, decreased with depth; this was also the case for moisture percentage, 

 redox potential, and temperature. Differences between these two parameters was 0.8 pH units in 

 the 0-5 cm interval, 0.5 units in the 5-10 cm interval, and only 0.3 units in the 10-15 cm interval. 

 The reasons for these differences are not apparent at the present time. 



The relative concentrations of elements and ions detected in the soil solution were, on the 

 average, Na>Ca = Si>Fe+' = NH3-N>Mg>Al>K->Fe+'>P04. As a first approximation, it does not 

 appear that any of these elements or ions are at levels low enough to cause deficiencies in the 

 primary producers, althoi^h P concentrations are probably marginal. 



There were very definite seasonal fluctuations in concentrations of elements and ions in the 

 soil solution. For some, such as Al, Fe + ', Fe + \ NH,-N. and Si, the fluctuations were comparatively 

 large whereas for PO4, Na, K, Ca, and Mg the fluctuations were smaller in amplitude. Fluctuations 

 were not parallel although data analysis will be required before details of this can be discussed. 

 Between 26 July and 6 August the concentrations of most of the elements and ions in solutions in 

 the upper 10 cm of soil decreased to a low and then increased between 6 August and 15 August. 

 This may be related to the transition through the growth peak of the vegetation which was consid- 

 ered to be sometime in early August. Fluctuations in concentration were not parallel between 

 depth intervals. For example, between 26 July and 6 August, when the concentrations of many of 

 the elements and ions in solution were decreasing in the upper 10 cm of soil, they were increasing 

 in solution at the 10-15 cm depth. 



53 



