194 BETTER DAIRY FARMING 



the feed. On the other hand the dairy cow which puts part of the 

 nutrients of her feed into milk can, of course, return the balance 

 only as fertilizing constituents. 



325. The fertilizer in feeds.— The following table from Cor- 

 nell Reading Course Lesson 141, by Fippin, shows the percentage 

 of fertilizing constituents returned in the manure under different 

 conditions : 



Nitrogen Percent 



Dairy animals 35 to 75 



Meat animals 65 to 90 



Work animals 85 to 95 



Phosphorus 



Young growing animals 35 to 50 



Dairy animals 50 to 80 



Work animals 75 to 95 



Potassium 



Dairy animals 65 to 85 



Meat animals 75 to 90 



Work animals 90 to 98 



326. Legume roughage the highest. — As regards home-grown 

 feeds, we have in manurial values another argument for using 

 legume roughage. Clover and alfalfa are higher in protein than 

 are other hays and the manure from them is higher in the fertilizing 

 constituent nitrogen. Of course, one might raise the objection here 

 that legumes must also take more nitrogen out of the soil and that 

 this fact would offset the greater amount of nitrogen returned in 

 the manure. Fortunately, this objection is not a real one because 

 legumes are able to take nitrogen out of the air and under proper 

 conditions of cultivation leave the soil actually richer in nitrogen 

 than before the crop was grown. No other crop can take nitrogen 

 out of the air. Thus legumes have the double advantage of enrich- 

 ing the soil during growth and in addition furnishing more nitrogen 

 in the manure than other roughages. 



327. Importance of manurial values. — To show the im- 

 portance of a consideration of manurial values in buying concen- 

 trates a table has been constructed to show what part of the cost 

 of a feed may be returned as fertilizer. The table has been made 

 on the basis that 55 per cent of the nitrogen, and 65 per cent of the 

 phosphoric acid and 75 per cent of the potash of the feed of the 



