A MAGGOT TRAP IN PEACTICAL USE. 



13 



the diagram, to have a cistern located between the platforms and a 

 pmnp that could be used in applying water to both piles. In making 

 plans for a maggot trap one must take into consideration the volume 

 of manure produced and the length of time it must remain on the 

 platform. As previously stated, it v.dU. be safe to estimate that the 

 production of manure per horse per day is 2 cubic feet and that after 

 10 days it will be practically free from maggots, provided it has been 

 well watered. 



THE INFLUENCE OF THE MAGGOT TRAP ON THE VALUE OF THE 



MANURE. 



Plate III illustrates an aU-too-common method of keeping manure. 

 It covers a large area of ground, and no attempt at heaping has been 

 made. The manure in such a pile is loose and shallow, and air 

 penetrates into practically all parts. These are the conditions 



Fig. 4. — Imaginary cross-section of an arrangement suggested for use where manure production is large. 

 a. Pump; c, concrete floor and walls of cistern; o, outlet pipes leading from floor of maggot trap to 

 cistern; p, platform maggot trap; t, cistern for liquid manure; g, ground level. (Original.) 



which give rise to the maximum loss of ammonia and nitrogen. It 

 also happens that the conditions which tend to the loss of nitrogen 

 arc the same which favor the development of fly larvae. An immense 

 surface Ls exposed for deposition of eggs, and the penetration of ah 

 makes it possible for larvae to feed in practically aU parts. The 

 fresher portion of the manure shown in this photograph was found 

 heavily infested all through the season. 



It has been shown that the losses occurring in manure thus care- 

 lessly stored will vary from 30 to 64 per cent of the total amount of 

 nitrogen (Beal, 1906), and that by careful methods of storage this loss 

 may be reduced to 15 per cent. Several methods of storage for the 

 purpose of preventing loss of ammonia and nitrogen have been 

 proposed. Among others is that recommended by Dcherain, Beal, 

 Tliornc, Ringclmuiiri, and others, which consists in keeping the manure 

 compactly h('ap(;d and W(J1 watered. Both heaphig and watering 

 t<!n(l to prevent the penetration of air and thus check the destructive 



