•404 Market-Garden Soils and Crops 



G. Boulder Clay Series. 



(a) Pure boulder clay soil formation. 



This formation is characteristic of mucli of the higher ground in the 

 district which is largely occupied by pasture, woodland, and mixed 

 farming. In some places the pasture is extremely poor and is slowly 

 going hack into scrub. This land has at some period been quite 

 largely used for ceical crops, for numerous fields can be seen laid in 

 baulks. It is a fairly heavy clay soil but the high percentage of 

 chalk, stones and fine gravel, added to the fact of better natural 

 drainage, malces its cultivation easier than the pure gault or O.xford 

 clay soil formations. The arable land of this soil formation is used for 

 cereals, horse beans, mangels, mangel seed and clover. Brussels sprouts 

 can be grown of good quality, and in places where the soil is a little 

 deeper late potatoes and onions do moderately well. 



The usual treatment of the land is somewhat as follows. Horse 

 beans (15 tons dung), wheat, oats without manure, potatoes (if the 

 soil is deep enough) (20 tons dung). Sometimes soot is used alone 

 for potatoes without dung. Needless to say the crop in these cases 

 is not very large. Clover seed is introduced occasionally into the 

 above rotation. Clover, sainfoin and lucerne, where grown, do well 

 on this soil formation, but cereal crops thrash rather lightly. 



Comjjosiiion. This formation is characterized by the rather high 

 but constant content of clay, 23-G per cent., a high content of calcium 

 carbonate, 4-8 per cent, (average) and a low content of phosphoric acid, 

 •15 per cent, (average). The available potash is usually about normal 

 but the phosphoric acid is invariably extremely low. One sample 

 taken from small-holding land but recently acquired by a parish 

 coimcil for small market-gardeners contained an abnormally low 

 content, '001 per cent, of available phosphoric acid. 



Sample 37 is an example of a deeper soil, resulting from local drift, 

 which is very heavily manured for potatoes, onions and parsnips. 



The pure boulder clay soil formation is one which requires scientific 

 treatment. Basic slag has wrought wonders at Croydon in the im- 

 provement of poor pasture, and phosphatic dressings are needed on 

 this formation for nearly every crop. 



{b) Clay loam formation {alluvial on boulder clay). 



This formation occupies a small area on the right-hand side of the 

 Ivel near Langford. It possesses a texture considerably lighter than 

 the pure boulder clay soil formation and is therefore used extensively 



