IMPROYEMEKT OF SOILS. 43 



strengthen its texture and improve it for every kind of 

 crop, need not involve the addition of more than fifty to 

 one-hundred cubic yards of marl or clay — an operation 

 which is quite within ordinary farm practice. In this 

 connection also it is necessary to ascertain the nature, 

 not only of the soil, but of the subsoil, the latter often 

 affording the readiest means of improving the former. 

 Where a vegetable or a sandy soil, for example, rests im- 

 mediately upon a substratum of clay which is near the 

 surface, the clay is often dug up and the surface top- 

 dressed with it. Oontrarywise, where the clay is upper- 

 most some good may sometimes be done by deepening 

 it and mixing it with the sandy layer below. Where the 

 soil and subsoil are similar in character and cannot be 

 used in that way, it may still happen that two soils of 

 opposite properties occur sufficiently near to one another 

 to be used for mutual improvement. 



There are situations, however, where neither of these 

 advantages will be found to offer; the field, the farm, or 

 even the entire district maybe uniformly sandy or clayey; 

 and other alternatives than mixing must then be resorted 

 to. The light soils will probably be consolidated by 

 sheep-foldmg, and by heavy rollmg; while the strong 

 lands will be rendered more workable by having green 

 crops plowed under and by being heavily dressed with 

 caustic lime in addition to ordinary manurings. 



The benefits of an admixture of soils are obviously two- 

 fold, the mechanical texture as well as the chemical com- 

 position of soils being altered and improved. A poor 

 sand, for instance, after an addition of clay or marl, is 

 rendered richer as well as stronger and more substantial, 

 so that plants thrive better in it, and a less quantity of 

 manure will suffice to afford a full crop. 



Claying, as we have seen, may be usefully followed as 

 a practice to be adopted and repeated on sandy, peaty, and 



