89 '^ 



CHAPTER Vril. 



OF MANURES. 



NeceMity of manures. Irrigation, its management and eflects. 

 Classification of manures : vegetable, animal, and mineral. 

 Vegetable manures -. ploughing in of green crops, of straw, of 

 seaweed, etc.; advantage of these forms of manure. Animal 

 manures : reasons for their remarkable efficiency. Animal 

 flesh, blood, wool, bones. 



SBCnON I. OF THE NECESSITY FOB MANURES I.\ MOST SOILS. 



Having now considered the character of the soil, 

 and that of the crops in connection with each other, 

 we see that there is no hope of keeping up an<l in- 

 creasing the pro<luce of any land, unless there is from 

 some source a supply of fertilizing substances to re- 

 store those that are carried away by the crops. Some 

 soils containing constantly decomposing rooks, or 

 peculiar springs, or subject to annual overflows where- 

 by cnriihin'^ sulistances are depo8ite<l, ne«l no other 

 foreiirn .sii|)ply; but these are rare when compared 

 with thoM" that riNpiire a constant and regular system 

 of atldition, tt) rentier them properly productive. 



To the various manures employed for this purpose, 

 we shall now turn our attention. Before taking them 

 up in any r(>gular classifieation, I may properly devote 

 a few wortls to one particular method of enriching the 

 soil, which cannot easily be brought into either (hUm 

 classes. 1 refer to irrigation. 



