On Poring and Burning. 27 



to think that under these circumstances ammoniacal manures 

 do more harm than good. At any rate, direct experiments, 

 repeated during three seasons, have shown me that on our farm 

 ammoniacal salts either produce no effect upon the produce of 

 roots or (if anything) diminish it. Many of the soils in this 

 neighbourhood are extremely thin ; and when it is considered 

 that the ashes produced from them contain a large supply of 

 readily available food, it will be easily conceived that the further 

 application of much farmyard-manure is likely to induce an over- 

 luxuriance in the turnips, which manifests itself in the development 

 of large tops to the injury of the bulbs. Having observed this 

 injurious effect of rich ammoniacal manures, I would suggest not 

 to use any farmyard-manure, or guano, or, indeed, any other 

 manure, in all cases in which a good quantity of ashes has been 

 produced upon a naturally poor and thin soil. 



The foregoing account of an inquiry undertaken with a special 

 reference to the cultivation of turnips on certain thin soils, I 

 trust embraces sufficient scientific and practical evidence to 

 warrant the following conclusions : 



CONCLUSIONS. 



1. The destruction of organic matter in soils adapted for 

 paring and burning is not attended with evil consequences, be- 

 cause such soils contain a large proportion of clay, which, like 

 organic matter, possesses the power of absorbing moisture and 

 fertilizing gases from the atmosphere. 



2. Inert vegetable matter is changed by paring and burning 

 into highly effective mineral food for turnips. 



3. The operation of paring and burning improves materially 

 the mechanical condition of naturally impervious soils by render- 

 ing them more porous and pulverulent. 



4. Not only does it improve the mechanical condition of the 

 soil, but it likewise contributes to highly important changes in 

 the chemical constitution of the soil constituents. 



5. It brings within reach of the young turnip crop a large 

 quantity of readily available mineral food from the soil. 



6. The ashes produced by paring and burning are especially 

 useful to turnips, and also to other green crops, because they 

 contain a large proportion of phosphates and potash, constituents 

 which, it is well known, favour in a high degree the luxuriant 

 growth of root-crops. 



7. The operation of paring and burning is applicable only on 

 soils containing clay ; in sandy soils it is undesirable, and likely 

 to do mischief. 



8. The beneficial effects of a fair quantity of vegetable ashes 



