94 THE ruiNcirLEs of AGIUCL'LTUKE. 



pig's, or other animals, to run npon the manure heap, 

 so as to keep it in a eompaet condition. 



2. The Escape of Liquids. — The liquid parts of manure 

 contain more than one half their value. It is important 

 that some dry, spongy substance, as straw, leaves, dried 

 nmck, or dry soil, be used to absorb and retain them. 

 The nitrogen which serves to form ammonia by fermen- 

 tation, is largely contained in the liquids, and the pres- 

 ence of these substances in some measure prevents the 

 escape of ammonia, by combining with it or a1)Sorbing it. 



The same j)urpose may be more fully accomplished by 

 ap})lying to the li(}uids sulphuric acid, or gypsum, which 

 is partly composed of that acid. 



3. Exposure to Rain. — The liquid parts contained in 

 manure, and held by absorl)ents, are readily washed out 

 l»y heavy rains. Both ammonia and nitric acid, the two 

 available forms of nitrogen, are largely lost in this way, 

 as well as some other elements. 



When manure is piled in heaps upon land which is to 

 be cultivated, it is true that these elements are washed 

 into the soil. This, however, involves waste, as the 

 small plots beneath the hea})s are too much overstocked 

 with these valuable substances to be able to render any 

 adecpiate returns in the crops. 



To prevent waste by washing, manure should be kept 

 under cover ; or, if exposed, should be so protected as 

 to I'eeeive only a small amount of rain, which would do 

 no barm. 



Methods of Applying Manure. — Whatever ])artieular 

 methods are employed in a])plying manure to the soil, 

 there arc two general i)rincij)les that should always be 

 l)orne in mind : — r 



1, It should 1)0 applied as soon as possible. All 



