W HF.AT SOILS (H-- Till- AI.i:.\ A X DK I A DIXlSHiN. 22 [ 



C lay. 



Alluvium 12. () iq.7 



Weald clav 2},.~ 20 . i 



Alexandria Soils — 



.\'n. 1 12.7 . 5 



Xo. ,^ 14.0 8.g 



Xo. 11 12.1 6.6 



No. 15 0.6 7.S 



iiven if the difference in the resi)ective sizes of the clay 

 narticles are allowed for. it appears clear that these four Alexan- 

 <lria soils contain less clay, and arc therefore dehnitelv lio^hter 

 than those from the Kno^lish wheat lands. Tlall and Russell 

 mention another soil — an alluvium from W'eyhridge — on which 

 they say "good wheat used to he i^rown. hut which has now heen 

 laid down to grass for manv vears." Its ])hysical composition 

 is as follows : — 



Fine Coarse and l-^'iiie sand l-jne silt 



gravel. medium sand and silt. and clav. 



1-3 38.4 45 5 8.9 



Here we have a soil which to some extent resemhles Xo. 5 

 «.f the Alexandria soils. Hall and Russell say of it: — 



Althougli so light in texture, the lield from wliich t'.ii- sample was 

 taken grows wheat excellently, because it lies below river level and has 

 f'ennanent z^ater at liille more than tzvo feet below the surfaee. This 

 will serve to illustrate the fact that the association of wheat with a i)arti- 

 cular type of soil really dei)ends ujjon the wa}- the soil maintains the 

 supply of water to the i)lant, and is therefore greatly affected l)y the 

 climate, or other external conditions which may cause variations in the 

 amount of water in the soil. The concejition nf wheat soil, tlien. which 

 may be obtained by considering the .urou]) nf .malyses. must only be 

 regarded as true for the soutli-east of England, with an average rainfall 

 of about 30 inches distributed very evenly throughout the year; it would 

 indeed serve well enough for all tlie whtat-growing districts of luigland. 

 but is unlikely that it re])resents the best tyjie of soil under such very 

 different climates as prevail in many extensive wIuat-gTowing areas. 



()f the nine soils in Hall and F^tissell's tahle, the lightest is 

 the Thanet sand, hut even that is heavier than anv of the 

 Alexandria .soils: the four heaviest of the latter are those that 



approach nearest to it. 77'.c-., Nos. 1 . 3, 11 and 1 S- Hall and 



Rtissell say of the Thanet sand : — 



This soil, though evenly textured, would l)e often of too light a 

 character for wheat, but the Thanet sands in I'.ast Kent are well sujiplied 

 with subsoil water, and crops on them rarely suffered from drought. 



One would like to know whether in former years the .\lex- 

 aiidria soils were better supplied with sul)soil water than they 

 are at present, and whether such a change may be included in 

 the causes contributing to the deterioration of the wheat lands. 

 Jt is said that even the best virgin soils of the area, if now put 

 down to wheat, seldom jjroduce a healthy cro]). and^this seems 

 to show that some such change as that may have affected both 

 virgin and cultivated soils ahke. 



