T. RiGG 411 



Composition. The texture of this formation is rather more sandy 

 in the neighbourhood of Langford and Eynesbury, but otherwise is 

 comparatively uniform over its whole extent. The soil is usually well 

 supplied with calcium carbonate, while the percentage of organic 

 matter and potash is invariably higher than that of the old brown 

 formation. The available plant food is very high on all the soils which 

 have been used for market-garden culture, but even soils in pasture 

 show a high content of available phosphoric acid (-OGQ per cent.). 



PART III. 



Relation of CrojJS to Soil Formations. 



Hall and Russell^ have demonstrated that by ^Dlotting the parish 

 returns of a crop by means of dots on the areas of the various soils of 

 each parish it was possible to bring out certain relationships between 

 crop and soil, when the crop map thus constructed was compared with 

 the geological map of the same area. Each dot represented a certain 

 number of acres of some crop and the density of dots on the crop map 

 revealed areas which were adapted to the growth of this crop. Thus 

 they were able to show that hops and potatoes were each associated 

 with certain types of soil. 



This method appears to meet with considerable success where the 

 soil occurring in a number of adjoining parishes is uniform over the whole 

 area, but where a number of soil formations are to be found in one 

 parish or adjoining parishes it is obvious that little relationship can be 

 shown to exist by indiscriminate application of this method. Thus 

 the relationship might not be brought out if the parish returns for a crop 

 were to be dotted evenly over the whole parish area, irrespective of 

 the fact that the crop may only occur on one of the several soil formations. 



In the market-garden district of Biggleswade, the writer found 

 many soil formations with distinct characteristics occurring in one 

 parish. Any method of plotting the acreage of a crop indiscriminately 

 over the parish area would thus have been useless for showing the real 

 distribution of crops. Two maps, Nos. 5 and 6, have been constructed 

 to show the result obtained by this method. Maps Nos. 7 and 8 have 

 been made by dotting the acreage of the same crops over the area of 

 the soil formation on which they occur. A comparison of the two sets 



' Hall and Russell, Agriculture and Soils of Kent, Surrey a7id Sussex. Publislied 

 by the Board of Agriculture and Fisheries, 1911. 



