108 MANURES. 



I'or a long time ohe of tlie strongest rccommentla- 

 lions of "book farming" was directed against the 

 practice of spreading manure upon the land more 

 than a day or two before it could be plowed under. 

 But on this point, practice has gained a triumph 

 over a crude theory. There is no doubt that manure 

 so spread is subject to some waste ; but that which 

 is not wasted is so much better incorporated with 

 the soil by the water of rains, which distributes its 

 soluble parts evenl}'^ among all of its particles, that 

 the effect produced is better than if the raw manure 

 had been immediately plowed under, necessarily 

 somewhat irregularly and in spots. In this latter 

 case there would be no loss of material, but some 

 parts of the soil would receive more than was neces- 

 sary, while others would be deprived of any material 

 beneiit, and the land would be less fertile than if 

 every root were sure to find, in every part of the 

 soil, its due proportion of the food. Ammonia is 

 formed only during decomposition ; and, especially 

 during cold weather, there is very little decomposi- 

 tion going on in manure which is thinly spread upon 

 the surface of the land ; hence the loss from this 

 cause is not great. 



In the case of very heavy nianuring, especially 

 with undecomposed manure on clay land, there is a 

 great benefit arising from the fermentation of the 

 dung in the soil, — a chemical action producing a 

 mechanical effect, — but ordinarily it is at least a ques- 

 tion whether it is not best to spread the manure 

 on the ?urface rs long as possible before plowing, 



