MANURES. 7X 



vcrizcs the land, — and would thoroturo bj' no moans rocommond to 

 leave the manure spread (m» tlie surlaeo without plouj^'liing- it in. 

 All I wish to enforce is, that when no other choice is left, but 

 either to set up the manure in a heap m the corner of the Held, or 

 to spread it on the field, without ploughing' it in directly, to adopt 

 the latter plan. Tn the case of very light sandy soils it nuiy per- 

 haps not be advisable to spread out the manure a long lime before 

 it is ploughed in, since such soils do not possess Ihc power of 

 retaining manuring substances in any marked degr(H>. On light, 

 sandy soils, I would suggest to manur<> with well-rerincnled duup; 

 shortly before the crop intended to be grown is sown. 



8. Well-rotten dung contains lilc(>wise little free ammonia, but a 

 very much larger j)r(»portioii of soluble organic and saline mineral 

 matters than fresh manure. 



9. Rotten dung is richer in nitrogen than fresh. 



10. Weight for weight, rotten dung is more valuable than fresh. 



11. In the fermentation of dung a very considerable proportion 

 of the organic matters in fresh manure, is dissipated into the air in 

 the form of carbonic acid and other gases. 



12. Properly regulated, however, the f(!rmentatit>n of (biiig is 

 not attended with any great loss of nitrogen nor of saliiu^ mineral 

 matters. 



13. During the fermentation of dung, ulmic, humicr, ;ind other 

 organic acids are formed, as wcdl as gypsum, which fix the ammo- 

 nia generat(Ml in the decomposition of the nitrogeni/ed constituents 

 of dung. 



14. During the Au-mentation of dung, the phosphate ol" lime 

 which it contains, is rendered more soluble than in fre.sh manure. 



15. In the interior and heated portions ol" niaiiiirc li(!apH, ammo- 

 nia is given off, but, on passing into tlu; cxtermU and cold layers 

 of dung heaps, the free ammonia is retained in llic heap. 



10. Ammonia is not given olV IVoin th(! snrface of well (com- 

 pressed dung heaps, but on fniiiing manure heaps it is wastoil in 

 appreciabhi quantities. Dung lu^aps for this r(!ason shonld not b(^ 

 turned more IVequcMitly than absolutely nec(^ssary. 



1*1. No advantage; appears to result from carrying on the fermen- 

 tation of dung too far, but every disadvantage. 



18. Farmyard manure becomes (h^teriorateil in value, when kept 

 in heaps exposed to the weatlier ; Hk; more; IIk; longer it is kept. 



19. The loss in manuring matters, which is incurred in keeping 



