T. RiGG 



415 



of baking to steely lumps if caught by a hot sun. Both soil formations 

 are rather small in area and perhaps it is hardly fair to include them 

 in the diagram at all. The old brown gravel soil formation also falls 

 below the main line curve, but. as previously explained, this formation 

 is farmed to a large extent owing to the great difficulty in obtaining 

 London dung so far away from any railway station. 



The one exception to come above the main line is that of the Oxford 

 clay with wash soil formation. This formation has been divided into 

 allotments on account of the great demand for small holdings. The 

 soil is not very suitable for most market-garden crops, but no other 

 land is available for market-garden purposes. 



100 



90 



80 



c3 c3 



a a 60- 



„ BC 50 - 



a a 

 be 



ftj 



40- 



Texture (clay + fine silt) 



The following table shows at a glance the proportion of each 

 market-garden crop on each soil formation. The percentages given are 

 percentages of the total arable land on each soil formation. These 

 figures are not tabulated for the purpose of finding the soil formation 

 most suited to a crop, because some of the soil formations are so small 

 in area that it would hardly be safe to do this. The suitabihty of a crop 

 to a soil formation is best divined by a study of the crop maps. This 

 table does, however, bring out the various proportions of the different 

 crops grown on any soil formation. 



