22 VEGETABLE uaRDEXIXG. 



those manures which are commonly sold by the trade. When of 

 a high price they are generally of a guaranteed composition 

 and they should be bought at a valuation based on the amount 

 of nitrogen, potash and phosphoric acid which they contain in 

 condition available to the roots of the plants. The most available 

 the form in which these materials exist in the fertilizer, the 

 more valuable it is generally considered. Most of the older states 

 require a guaranteed analysis to accompany tbe packages in 

 which the fertilizers are sold and exercise some supervision over 

 the business. Among the most common of this class of fertil- 

 izers are the following: 



Tankage. — This is the refuse product from slaughtering 

 establishments, which after being relieved of its fat is brought 

 to drjmess and ground. It is very rich in nitrogen and phos- 

 phoric acid, but contains very little potash. Most of the nitro- 

 gen and phosphoric acid which it contains is available to the 

 roots of plants. It is probably the cheapest source of nitrogen 

 and phosphoric acid to be found in the western states. It varies 

 considerably in composition, and this may sometimes be ac- 

 counted for by the fact that in some establishments the blood 

 is separated from the other offal, thus reducing the percentage 

 of nitrogen in the tankage. It is rather a slow acting fertilizer. 

 Tankage may be safely used in quantities of less than 1,000 

 pounds per acre if applied broadcast and worked into the soil. 

 Four hundred pounds per acre is generally considered a good 

 application. It may be safely used in these quantities around 

 growing plants of cabbage, corn, lettuce, etc., provided it is 

 spread out evenly and does not come in contact with the roots 

 of the plants. 



Ground Blood is very rich in nitrogen and quite difficult 

 to dry thoroughly. If it is at all moist it is likely to heat badly. 

 It is a quick acting fertilizer, and is seldom used without being 

 mixed with other materials. 



Ground Bones are always rich in phosphoric acid, but 

 ground fresh bones are better than dry bones since in addition 

 to phosphoric acid they have quite a large percentage of nitro- 

 gen, which amount is very small in bones that are old and dry. 

 It is always best to break or grind the bones that are to be 

 used on the land and in many cases to then mix them with fer- 



