542 



VARIOUS FERTILITY FACTORS 



straw for bedding, would make a ton of manure containing 500 

 pounds of dry matter, about 12^ pounds of nitrogen, 2 pounds of 

 phosphorus, and 9^ pounds of potassium. Or a ration containing 

 500 pounds of timothyhay and 310 pounds of oats, with 270 pounds 

 of oat straw for bedding, would make a ton of manure containing 

 500 pounds of dry matter, about n pounds of nitrogen, 1.7 pounds 

 of phosphorus, and 9 pounds of potassium. Some loss of nitrogen 

 is likely to occur by volatilization, and both nitrogen and potassium 

 are very likely to be lost in the liquid excrement. 



For the most common rations used in live-stock farming, 10, 2, 

 8 represent very approximately the average pounds of the three 

 elements, nitrogen, phosphorus, and potassium, in a ton of " aver- 

 age fresh manure." By leaching and fermentation the dry matter, 

 nitrogen, and potassium are lost in approximately the same pro- 

 portion, but the phosphorus is lost only about half as rapidly, so 

 that one ton of average yard manure, resulting from perhaps two 

 tons of fresh manure, contains about 500 pounds of dry matter, 

 10 pounds of nitrogen, 3 pounds of phosphorus, and 8 pounds of 

 potassium, one half of the dry matter, nitrogen, and potassium, 

 and one fourth of the phosphorus having been lost. 



Wheat bran contains about 24 pounds of phosphorus per ton, 

 so that, for every 100 pounds of bran used in the ration, nearly 

 one pound of additional phosphorus will be found in the manure. 

 This illustration and reference to the average composition of food 

 stuffs will show how important the factor of food is in affecting 

 the quality of manure. 



Most analyses of manure represent the product in a more or 

 less decomposed state, in which case the phosphorus content is 

 likely to be appreciably higher than in strictly fresh manure, and 

 even manure commonly called fresh is likely to have lost some 

 nitrogen and potassium in the liquid excrement. The following 

 analyses include some accepted averages from the best authorities. 



While these general averages may be satisfactorily applied to 

 large quantities of mixed manure, or in estimating the amounts 

 of plant food in repeated applications of fresh or yard manure, 

 respectively, they cannot safely be used for small single lots, unless 

 the per cent of dry matter is determined and the character of the 

 feed and bedding used is known. 



