144 BOARD OF AGRICULTURE. 



"But," it may be asked, "will not this fresh manure decom- 

 pose in the soil and furnish ammonia?" In light, sandy soil 

 I presume it will do so to a considerable extent. We know 

 that clay mixed with manure retards fermentation, but sand 

 mixed with manure accelerates fermentation. This, at any 

 rate, is the case when sand is added in small quantities to a 

 heap of fermenting manure. But I do not suppose it would 

 have the same effect when a small quantity of manure is mixed 

 with a large amount of sand, as is the case when manure is 

 applied to land and ploughed under. At any rate, practical 

 farmers, with almost entire unanimity, think well-rotted 

 manure is better for sandy land than fresh manure. 



As to how rapidly, or rather how slowly, manure decom- 

 poses in a rather heavy, loamy soil, the above experiments of 

 Mr. Lawes afford very conclusive, but at the same time, very 

 discouraging evidence. During the nineteen years thirty- 

 eight hundred pounds of nitrogen and sixteen thousand four 

 hundred and ninety-two pounds of mineral matter in the form 

 of farm-yard manure were applied to an acre of laud, and the 

 nineteen crops of barley in grain and straw removed only 

 three thousand seven hundred and twenty-four pounds of 

 mineral matter and one thousand and sixty-four pounds of 

 nitrogen. The soil now contains, unless it has drained away, 

 one thousand seven hundred and thirty-six pounds more 

 nitrogen per acre than it did when the experiments com- 

 menced. And yet forty-one pounds of nitrogen, in an avail- 

 able condition, are sufficient to produce a large crop of barley, 

 and eighty-two pounds per acre furnished more than the 

 plants could organize. 



I have not time to discuss this matter ; but it is certainly 

 well worth considering whether we cannot discover some 

 method of fermenting manure so thoroughly without loss that 

 the nitrogen which it contains shall be rendered soluble and 

 available before it is spread on the land. The soil is so con- 

 servative that when it gets hold of manure it is very slow to 

 part with it. It holds it with almost a miserly grasp. The 

 practical difficulty in fermenting manure, without loss, is to 

 keep it moist enough without allowing any of the liquid to 

 leach out. If this can be accomplished, the more we reduce 

 our manure by fermentation the better. 



