Ma/nurial Value of Feeding Stuffs. 269 



a ton of bran contains nitrogen, phosphoric acid and potash in 

 such amount that if bought in the form of commercial fertilizers 

 they would cost at least the sum named. They mean that the 

 farmer who harvests a ton of corn and seeks to return to the field 

 the same amount of fertility that was abstracted by this crop 

 must pay not less than $6. 74 for the requisite fertilizers, if bought 

 in the market. Virgin soils as a rule contain a large amount of 

 available fertility, and pioneer farmers, drawing upon Nature's 

 store, give little consideration to the subject. The "Western 

 farmer cultivating prairie lands, when marketing corn considers 

 that in so doing he is selling labor and perhaps rent of the land; 

 but rarely does he realize that he is also selling fertility, to re- 

 place which would cost as much and often more than the crop 

 brings. The Eastern farmer and Southern planter are now culti- 

 vating soils which have been so depleted of available plant food 

 that the subject of fertilizers is a matter of the deepest concern 

 to them. 



When one who cultivates the soil must choose between com- 

 mercial fertilizers and barn-yard manures, it is reasonable to 

 estimate that the latter have a value of at least two-thirds the 

 former, based on their nitrogen, phosphoric acid and potash con- 

 tents. Because the soils of the West are still rich in original 

 fertility, the farmers of that region have as yet little need of 

 commercial fertilizers, and barn-yard manures in consequence 

 have a lower value than in the older-settled regions. For con- 

 venience of comxjarison, it is perhaps best to use the same valua- 

 tions for nitrogen, phosphoric acid aud potash in farm manures 

 that these same compounds command when sold in the form of 

 commercial fertilizers. Such values should always be used, how- 

 ever, under the limitations above presented. With sharp com- 

 petition confronting every one who cultivates the soil, the 

 careful saving of farm manui"es and their judicious application 

 are vital factors in farming operations, and as essential to con- 

 tinned success as plowing the land or planting the crop. 



423. Manure produced by farm animals. — Eoberts ^ gathers the 

 following interesting data showing the daily and yearly produc- 



' The Fertility of the Land. 



