Food for Plants. 161 



Its effect is to produce larp^er crops per unit of uitro- 

 g-en, and these crops, in turn, leave behind in the soil 

 larger crop residues, and with carbonate of lime to aid 

 in their decomposition these furnish a sufficient supply 

 of organic matter to keep the soil in good physical 

 condition. 



REFERENCES 



(1) Blair, A. W., and McLean, H. C 1917 Total nitrogen and 



carbon in cultivated land and land abandoned to grass and 

 weeds. In Soil Sci., v. 4, no. 4, p. 283-294. 



(2) Coleman, D. A. 1917 The influence of sodium nitrate upon 



transformations in soils with special reference to its avail- 

 ability and tliat of other nitrogenous manures. In Soil Sci, 

 V. 4, no. 5, p. 345-432. 



(3) LiPMAN, J. G., AND Blair, A. W. 1916 Investigations relative 



to the use of nitrogenous plant foods : 1898-1912. N. J. 

 Agr. Exp. Sta. Bui. 288. 



(4) Russell, E. J. 1915 Soil Conditions and Plant Growtli, new 



ed., p. 83, Longmans, Green and Co., New York. 



(5) Russell, E. J., and Richards, E. H. 1917 The changes taking 



place during the storage of farmyard manure. In Jour. Agr. 

 Sci., V 8, p. 495-563. 



Cost of Transportation of Fertilizers. 



A striking illustration of the difference in the cost of 

 transportation by four different ways is given below^: 



To transport a ton by 



Horse power, 5 miles; 

 Electric power, 25 miles; 

 Steam ears, 250 miles; 

 Steamships on the lakes, 1,000' miles; 

 costs the same amount in each case and the same amount of money will 

 haul a ton 



5 miles on a common road, 

 1.5 miles on a well-made stone road, 

 25 miles on a trolley road, 

 250 miles on a steam railway, 

 1,000 miles on a steamship. 



It will be seen that the same amount of money it takes 

 to haul a given amount of produce five miles on a public 

 highway of the United States will pay the freight for 

 250 miles on a railroad and 1,000 miles on a steamship 



