SOIL TYPE, SOIL WATER REGIME AND GROWTH 315 



Table i 

 Field characteristics of five soils 



Code Cover Soil type 



Horizon 



Colour 



D—Deschampsia; H=Holciis 



Apparent 

 density 

 pH gm/cc 



BL D.flexuosa Iron-humus Ao, 10-25 cm Grey 3*2 2-1 



podsol 



SH H. mollis Oligotrophic (B), 5-25 cm Brown 4-1 1-3 



Endyinion brown earth 



BR D.flexuosa PodsoHsed (B), 5-25 cm Red- 3-6 1-7 



brown earth brown 



D D.flexuosa PodsoUsed Ag, 0-8 cm Black 2-9 0-38 



brown earth 



H Oak leaf PodsoHsed A 0, 0-12 cm Black- 3-0 0-35 



litter browii earth brown 



Table 2 

 Characteristics of the soils (treatment i) at the end of the experiment 



N.B. pH determined with glass electrode; soil :water= 1:1 by volume. 'Humus' 

 determined from 'loss on ignition' at 550°C. Apparent density determined from 

 volume displacement of toluene (after c. 10 sec) by natural clods, followed by filtering 

 and dry weight determination of the clods. Exchangeable Ca and K extracted by 

 shaking with 2 successive quantities of 0-5 N NH4NO3; estimation by 'Versenate' 

 titration and flame-photometer respectively. Oxygen diffusion rate (ODR) deter- 

 mined with platinum electrode (Poel, i960); in g x lO"^ of oxygen per sq. cm per 

 min. 



For complete descriptions of the methods, seejarvis, P.G., i960. 



