308 MANURES AND THEIR APPLICATION. 



diminished, and that there was a corresponding increase in the 

 proportion of organic matter, and especially of nitrogenous 

 matter, and more especially in the soluble part of these in- 

 pTedients ; the manure not only became more concentrated but it 

 also became more matured, more capable of acting immediately 

 as plant food. Heap I. deteriorated from the beginning but 

 especially after six months, and at the end of nine months 

 about half of its valuable ingredients had disappeared ; they had 

 gone to enrich the soil immediately around the heap. Heap 

 III. lost quality to a still greater extent, but its valuable con- 

 stituents went to enrich the whole soil over which it was 

 spread. 



These heaps were small, and the loss which occurred was pro- 

 portionally great, but even in the case of large manure heaps 

 exposed to the weather, the loss sustained is very consider- 

 able. 



The above analyses and many others show that ordinary farm- 

 yard manure contains nitrogen equal to nearly 1 per cent, of 

 ammonia, and that at least a quarter of this is soluble and easily 

 washed away. Experiments in this country and elsewhere have 

 also shown that in about six months the half of the soluble in- 

 gredients may be washed away. In a heap of 1000 tons there 

 may be therefore a loss of more than a ton of ammonia, whose 

 value is nearly £100. But analysis of the wash shows that a 

 large amount of phosphoric acid and potash is also being lost 

 which may represent somewhere between £50 and £100. In a 

 large and well-compacted manure heap the loss may not be so 

 great as I have indicated, but it seems highly probable that the 

 ordinary loss is not less than £10 for every hundred tons or 

 £1 for every 10 tons of manure. Surely some sort of covering, 

 even sheds of a portable kind, could be made at little expense 

 to prevent this great waste. 



We hear of means being adopted to fix the ingredients of 

 manure heaps, but no means are of any avail unless the manure 

 is under cover. With the manure under cover it is possible to 

 prevent almost all waste. Many experiments have been made 

 to discover the best means of preserving the valuable constituents 

 of a manure heap. 



Here is a very interesting experiment made by Prof. Wolff 

 of Hohenheim, to whose valuable researches agriculture is so 

 greatly indebted. Operating with small quantities he divided 

 a well-made sample of manure into five parts, one was exposed 

 and four were covered, and t® three of the covered pprtions he 

 added charcoal, gypsum, and slaked lime respectively, and the 

 table shows the percentages of ingredients remaining after the 

 experiment had gone on for fifteen months. 



