NITROGEN IN AGRICULTURE. 177 



that are apt to show themselves in the top as decomposition pro- 

 gresses, letting out bad odors unless promptl}' closed. 



As the presence of oil or salt tends to check decomposition, fish- 

 waste containing much of these liad better be composted with 

 stable manure rather than soil, as the heat from the manure will 

 promote decomposition. If decomposition is slow to start, un- 

 leached ashes, or lime and plaster, may be mixed with the mass ; 

 but be sure to cover such heaps with soil. When manure is not 

 used, the compost heaps sliould be made, if possiMe, before warm 

 weather closes ; and, after it lias lain a couple of weeks, should no 

 heat be found by driving a bar dowu, and testing it, then pitch 

 it over to let the air in, and cover tlie outside lightly with soil. 

 Stable manure which has heated and become " fire-fanged," thereby 

 losing its nitrogen, can sometimes be bought at half price, and th-e 

 nitrogen can be restored by composting it with fish. 



Where chum is used, after having been made fine it can be ap- 

 plied directly to the surface of tillage land in the fall, and harrowed 

 in or ploughed lightly under, to be thrown up near the surface by 

 a deeper ploughing in the spring. If left on the surface I find it 

 is spreading a table all winter long for the crows of the country. 



By applying the chum in the fall it will have the advantage of 

 rain and frost aiding to subdivide and dissolve it. Fish-skins, for 

 use on tillage land, had better first be composted. If to be used 

 on sward land for grass, spread thin in the fall or ver^- early spring. 



How MUCH Fish- Waste should be used to the Acre? — To 

 determine this we must consider two points : First, what proportion 

 of it will make digestible plant food the fii'st season ; and, secondly, 

 what and how much of the phosi)horic acid and ammonia found- in 

 them do the crops we propose to raise requii-e? I think we can 

 assume, as a general truth, that nearly all the ammonia becomes 

 plant food the same season it is applieil, while not much over one- 

 half the phosphoric acid can be safely counted on. If we use 

 fish-waste on the same land the second year we may assume that 

 all the phosphoric acid is available, for by that time the half left 

 over from last season will have decomposed. 



Waste fish, particularly manhaden, are often used along the sea- 

 coast as a top-dressing for grass. This is a great forcing process, 

 and for a time enormous crops of ha}- can be grown ; but eventu- 

 all}', and especially on light soil, the crops grow less and less, 

 when generally a larger quantity of fish is applied, resulting in 

 still more harm, until the soil utterly refuses to respond, bakes 



