352 



SYSTEMS OF FARMING 



6. The fertilizing elements contained in purchased feeds fed 

 minus the loss in feeding is to be regarded as gain to the soil.^ 



7. The nitrogen in clover, alfalfa and other legumes fed on the 

 farm minus the loss in feeding is to be regarded as gain to the soil. 



8. The nitrogen in clover, or other legume plowed under, is 

 to be regarded as gain. (Estimate yields in terms of hay.) 



9. The fertilizing elements contained in straw purchased for 

 bedding are to be regarded as gain. 



10. The fertilizing elements contained in fertihzers purchased 

 are gain. 



The Nitrogen-Phosphorus Balance Sheet. — ^The application 

 of these rules can best be illustrated by the following problem: 



On a dairy farm of 120 acres the following crops are grown: 



Crops 



Acres 



Average Yield per Acre 



Com 



25 

 25 

 15 

 10 

 25 



10 



12 tons silage, 65 bu. corn 



Oats 



50 bushels 



Clover (medium red) 



2 tons (1 cutting) 



Alfalfa 



43^ tons (3 cuttings) 



Pasture in rotation 



Equivalent to 134 tons mixed grass 



Barley 



hay per acre 

 30 bushels 







All the milk produced is sold. 



All crops harvested, except the barley, ten tons of clover hay and 250 

 bushels of oats, are fed on the farm. ^ 



Manure is hauled directly to the field or stored in a manure shed when it 

 cannot be haxiled directly to the fields. 



Two hundred fifty bushels of oats and all the barley are sold. 



Ten tons of clover hay (red clover) are sold. 



Seventeen acres of com are made into silage. 



Eight acres of com are shredded. About one-half the shredded stalks 

 is used for bedding. 



All straw is used for bedding. 



The second growth of clover is plowed under (equivalent to one ton of 

 hay per acre). 



Ten tons each of wheat bran and gluten feed (high grade) are purchased 

 and fed annually. 



Three hundred pounds of acid phosphate (seven per cent phosphorus) 

 are applied per acre to the com land. 



Determine the annual loss or gain of nitrogen and phosphorus in this 

 system of farming. 



» When the^skim milk is fed on the farm it should be considered as pur- 

 chased feeds, since the losses in the feeding transaction include milk production. 



