Live Stock Breeders' Association. 257 



It should be remembered that legume crops, as clover, cowpeas 

 and soy beans, are rich in both nitrogen and phosphorous, three 

 and one-half tons of clover hay containing as much phosphorus 

 and 40 pounds more nitrogen than 100 bushels of corn. 



If the crops are fed to live stock, it is well to know that 

 about one-fourth of the nitrogen and one-fourth of the phosphorus 

 are retained in the flesh and bone of the animal, while three-fourths 

 of the nitrogen and phosphorus and practically all of the potas- 

 sium are returned in the solid and liquid manure. 



Thus we have another process of separation by which part of 

 the needed nitrogen and phosphorus leaves the farm with the ani- 

 mals, while the potassium is again returned, even though it may 

 not be needed. 



It should be a plain fact that manure made from animal excre- 

 ments with straw or stalks for bedding must be deficient in nitro- 

 gen and phosphorus, but well supplied with potassium. 



In the case of nitrogen, the difficulty can be overcome by mak- 

 ing a liberal use of clover or other legumes in the crop rotation 

 and as catch crops, turning under these crops and crop residues so 

 far as practicable. Legume crops may also be used in pastures to 

 a considerable extent, and in three different ways it is possible to 

 secure sufficient nitrogen from the air to balance the deficiency in 

 the manure. 



With the phosphorus the difficulty is greater, because the 

 proportion contained in the manure is less, and there is no such 

 ever-present inexhaustible supply as in the case of nitrogen. 



It must be apparent that to increase the value of farm manure 

 we should add phosphorus to it. Thus we can balance manure, and 

 when used on soil rich in potassium in rotations with nitrogen- 

 fixing legume crops, we can provide plant food in a balanced ra- 

 tion to meet the needs of the maximum crop yields. By these 

 means we can check the progress of soil exhaustion and even grad- 

 ually increase the fertility and productive capacity of the land. 

 Indeed, we can thus profitably enrich such land even beyond its 

 virgin fertility. 



By far the cheapest form of phosphorus is fine-ground raw 

 rock phosphate. This material is but slightly available for the use 

 of crops if applied to soils deficient in decaying organic matter; 

 but if applied in intimate connection with rotting manure, it is thus 

 made soluble and available for plant growth. 



Certainly one of the most profitable, and probably the very 

 most profitable, method of maintaining the necessary supply of 



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