26 



SCIENCE AND FRUIT GROWING 



instances selected being such as are of more general occurrence. 

 One of these was a light, sandy soil, where little or no effect 

 might have been expected from trenching (without manuring), 

 but the other three were eminently cases where trenching would 

 generally be advocated, and where, as a matter of fact, it has 

 been adopted wherever high-class fruit culture has been embarked 

 upon. Two of these were at the Fruit Farm, one on the heavy 

 clay soil at the lower part of the farm, and the other on the upper 

 ground, where the proportion of sand in the soil justifies its 

 being termed a loam, though it is, in winter, as heavy and sticky 

 as most clay soils (see p. 81). Both stations, in fact, are on the 

 Oxford clay formation, and the shallowness of the surface soil, 

 and the compactness of the subsoil, are very unfavourable for 

 the penetration of roots (see p. 309). It is certainly a soil 

 which would be likely to benefit by trenching, as the subsoil 

 evidently requires aeration. The other instance was a heavy 

 loam, overlying clay with chalk under it, in Broadbalk field at, 

 Harpenden. The differences between these soils are brought 

 out by the following analyses of them. 



MECHANICAL ANALYSIS OF THE SOILS 1 



Surface 



The investigation, in which Dr. E. J. Russell participated, was 

 of a twofold nature, consisting, on the one hand, of ascertaining 

 the behaviour of trees and bushes planted in trenched and un- 

 trenched sections of the ground, and, on the other hand, deter- 

 mining the effect of the trenching on the water contents and 

 nitrates in the soil, the latter affording evidence of such changes 

 as had occurred in the bacterial conditions from the physical 

 alterations produced by the trenching. 



1 For more detailed results, see p. 83. 



