THE MANURIAL VALUE OF ASHES, "MUCKS," SEA- 

 WEEDS AND BOXE. 



Chas. D. Woods. 



In his efforts to grow crops the intelligent farmer must ever 

 try to conserve and add to the stock of available plant food in the 

 soil. The fertility of a soil is measured by its power to produce 

 crops. A soil may have many hundreds of pounds of plant food 

 per acre, and still be unfertile, while another may contain little 

 plant food, but may have that little in an available form and thus 

 be productive, i. e., fertile. 



Usually manures are applied to soils for the double purpose of 

 supplying plant food in an available form and unlocking the 

 unavailable compounds already in the soil. The direct manurial 

 value of fertilizing materials of the same class can be accurately 

 measured by chemical analysis. Sometimes as the results of 

 field and pot experiments it is also possible to extend this com- 

 parison of analyses to materials of unlike nature. In general, 

 however, it is not enough to know the pounds of nitrogen, phos- 

 phoric acid and potash in a given manure, but we must by actual 

 experiment with the living plant find out how much of these 

 materials is available to the plant. In studying the manurial 

 value of the three classes of fertilizing materials discussed in 

 this bulletin, these facts must be kept in mind. For example, in 

 comparing a "muck" with 2^2 pounds of nitrogen in 100 pounds 

 of dry matter with stable manure with only i$4 pounds of nitro- 

 gen in the same weight, a great mistake would be made in think- 

 ing the muck a better fertilizer than the manure. The nitro- 

 gen of the muck is largely unavailable as plant food until it has 

 been treated by composting, exposure to the air, etc., while the 

 stable manure contains in itself the ferments necessary to render 

 its nitrogen available to the growing plant. In like manner the 



