6 



HOCKINGS' GARDEN MANUAL 



from it in his crops. Such being the case, it will be 

 admitted that deep ploughing will afford greater scope 

 for the roots, more food for the plants, and conse- 

 quently the land will not be so soon exhausted ; it 

 will be almost like two fields in one. In shallow 

 ploughing a hard " pan " is formed at the bottom, as 

 impervious to water as if it had been puddled, and 

 during our heavy and continual rains everything is 

 flooded and destroyed. In drought the result is equally 

 disastrous, for the four or five inches of earth is soon 

 dried through to the hard bottom, and the crop either 

 perishes or yields no return. 



There are some subsoils which are unfit for the 

 support of vegetable life until exposed to the action 

 of the atmosphere, and thus in shallow tillage the 

 roots, on reaching the undisturbed subsoil, run along 

 without penetrating it, and are forced to depend 

 entirely upon the few inches of surface soil for sup- 

 port, exposed alike to destruction by either drought 

 or flood. As an instance of this, some clay subsoils 

 may be mentioned which owe their color to the pre- 

 sence of protoxide or oxide of iron, which is deleteri- 

 ous to vegetable and animal life ; but, by thoroughly 

 draining and breaking this soil, and thus fully expos- 

 ing it to the influence of the atmosphere, more oxygen 

 is absorbed, and this injurious agent is converted into 

 peroxide of iron, which is beneficial and necessary, 

 being a great promoter of vegetation. It also fre- 

 quently happens that from want of mixture the 

 surface soil is deficient in some of the important 

 earths and saline matters in which the subsoil is rich. 

 In most cases, however, it will be best to break up 

 the subsoil without bringing it to the surface, and 

 gradually mix it with the surface soil at each subse- 

 quent ploughing, as it gets sweetened and ameliorated 

 by exposure to the air and rain ; and this may readily 

 be accomplished by using the trenching plough in the 

 bottom of the furrow after the common plough — for 



