APPLES. 343 



Lincoln, including the Trent valley (Nottingham), and watered by rivers having their con- 

 fluence in the Humber ; the extensive valley of the Thames, the Severn valley, and that 

 of the Mersey and other rivers. In these, alluvial soils have overlaid the original rocks, 

 and, where situated above the line of fog, are suitable for apple production, but always 

 contingent on a sufficient depth of loamy soil and efficient natural or artificial drainage. 



Brick-earth affords a good example of loamy soil in which apple trees thrive. It 

 obtains in the south, where there has been no drift in its original state as worn from 

 hillsides. Fertile accumulations of brick-earth occur in the lower Thames and Medway 

 valleys. Indeed, the slopes overlooking the Medway, as well as the deep brick-earth of 

 the valley stretching from Canterbury to Chatham, are famous for fruit production. 

 Brick-earth, however, is not absent from drift, for it occurs in Middlesex, Essex, Hert- 

 fordshire, and many other counties. Brick-earth on the north of the Thames differs from 

 that south of that river in that it was transported, and the soil is more or less mixed. 

 Wherever alluvial or brick-earth soils occur on favourable exposures, those are apple- 

 producing staples. The reason is that a mixing of two or more different soils effects 

 improvement in their staple and constituents. 



The soil formed at the outcrop together of two rock formations, as carboniferous 

 limestone and lower limestone shale, oolite and lias, chalk and upper greensand, magne- 

 sian limestone and new red sandstone, is more fertile than the soil of any one of those 

 formations by itself. What nature has left undone, cultivators strive to effect in the 

 operations of chalking, liming, marling, claying, and sometimes paring and burning, 

 namely, the mixing of soils, and thus render some hitherto unsatisfactory capable of 

 higher production. 



The apple tree requires 12 to 18 inches in depth of ameliorated substantial loam, 

 and a similar thickness of good staple below it, the whole open and accessible to air 

 by efficient drainage. Marly soils afford the greatest wealth in apple crops, because 

 they are rich in all the ash elements of apples, and the trees are healthy through lime 

 being abundant, apple-wood ash containing 63-60 per cent, of lime. Clay marls and all 

 clay soils are richer in, and make better use of, potash than light soils, and apple-wood 

 ash contains 19-24 per cent, of potash ; therefore, clayey soils produce healthier apple 

 trees than are those of a brashy nature. Alluvium and drift soils that have long been 

 cropped are improved for apple culture by liming, and light soils are benefited by marling. 



The apple does not succeed in hot sandy soils, shallow loam on chalk, in water-logged 

 land, or a medium soured by stagnant organic acids and pan-forming iron oxides. These 



