THE IMPROVEMENT OF THE SOIL. 25 



liable to wash away. If equally rich, they furnish plants 

 with a more abundant supply of food than shallow soils. 

 Especially for all tap-rooted plants, a deep soil is indis- 

 pensable. In the preparation of your garden, then, see 

 that the ground is dry, deep, and rich. Good vegetables 

 will not grow in a wet soil ; a shallow soil will not fur- 

 nish them with a regular supply of moisture ; and the crops 

 growing upon a poor soil never repay the labor bestowed 

 upon it. 



CHAPTER III. 



THE IMPROVEMENT OF THE SOIL. 



A soil may be improved in texture, in depth, and by the 

 addition of such constituents necessary for the growth of 

 plants as may be wanting. 



The texture of a clayey soil can be rendered more per- 

 vious by thorough draining, deep trenching, and by the 

 application of sand, ashes, lime, and unfermented manure. 

 Any clayey, retentive subsoil will be greatly benefited by 

 good underdrains. A wet soil is always cold, as water 

 has a much greater capacity for heat than has earth. 

 The same quantity of heat that will warm the earth four 

 degrees will warm water but one. Water, also, is a bad 

 conductor of lieat downwards. Boiling water can be 

 gently poured over cold water without heating the latter, 

 except a very little at the surface. Now, if the soil in 

 spring be saturated with water colder than the summer 

 rains, unless it be removed by drainage, they cannot de- 

 scend to carry warmth into the ground ; neither will the 

 wet soil conduct the atmospheric heat downwards with 

 much rapidity. But draw off the cold water by proper 



