32 SOILS AND MANURES. [chap. II. 



tageously buried at the roots of the plants from 

 which they were taken. It may seem strange 

 that growing a crop on land and then burying it 

 should produce any good effects, as it appears 

 to be only restoring to the soil what the crop 

 had taken from it; but the fact is, the crop 

 buried derived a great portion of its nourishment 

 from the air, and these nutritious matters are 

 more equally distributed through the soil by the 

 operation of digging the crop in, than they can 

 be in any other way. 



Green crops are, indeed, much better manure 

 than decayed leaves ; as the latter, when they 

 have been suffered to ripen and fall naturally, 

 are found to abound in saline and earthy matters, 

 but not to contain much of the other elements 

 necessary to vegetable life. 



Charcoal and soot are excellent manures in 

 some cases, as they abound in potash ; and they 

 are particularly efficacious when applied to some 

 of the kitchen crops, such as onions and all 

 the cabbage tribe. When thus applied the 

 charcoal should be in a powdered state ; but it 

 may also be most advantageously used in pots 

 broken into small pieces and mixed with chopped 

 turf; as in this state it keeps the earth open, 

 and allows of the passage of the air in a state 

 of minute subdivision to the roots. 



Chopped turf is an excellent kind of manure, 

 especially for peach and other fruit trees, as the 

 roots of the grass keep the ground open for 

 the passage of the air. 



Mineral manures are more used in agricul- 

 ture than in gardens, but lime may be em- 

 ployed advantageously when the ground has 



