PLOWING. 



97 



constantly going on in the earth, to bring that soil up to the degree of fertility that it had 

 attained &quot;before the plowing. 



ADVANCE CHILLED PLOW, 



It is sometimes de 

 sirable to break up the 

 subsoil, which can 

 easily be accomplished 

 with a good subsoil 

 plow without bringing 

 it to the surface; but 

 the instances are very 

 rare where benefits 

 will be derived by 

 mingling it to any 



OLIVER CHILLED PLOW. great extent with the 



surface-soil, and it should always be done with great caution. &quot;When the surface-soil is very 

 sandy, with a subsoil of stiff clay, or the reverse, such soils may be improved bv mixing the 

 clay and sand as thoroughly as prac 

 ticable, and subjecting them to the 

 various processes of proper tillage. 

 Soils of great value are sometimes pro 

 duced in this way from such as have 

 previously been considered of inferior 

 quality. 



Sometimes the subsoil is a hard clay, 

 almost impervious to water; hence, in 

 rainy seasons, the surface-soil is satu 

 rated with a surplus of water that can- THE QQODALL 

 not make its escape downward through 



STONE AND 



SUBSOIL PLOW, GRUB-HOOK, 

 ROOT-PULLER. 



the impenetrable layer beneath, and the land must depend almost wholly upon evaporation 

 for becoming dry enough to promote the growth of crops; in such cases, a breaking up of 

 the hard subsoil will materially improve the condition, as it furnishes room for deep-rooted 

 crops, and a means of drainage by opening a way of escape through it for the surplus water 

 in the soil, and also admits of the moisture from beneath finding access to the roots of plants 



