FERTILIZERS. 127 



practicall}" as good results as a mixture containing nitrate of soda in 

 addition to these." In one experiment phosphoric acid and nitrogen 

 appeared to be the fertilizing constituents most needed for wheat. 

 The results of the other wheat experiment were inconclusive. Lime 

 was in general beneficial. 



The maintenance of fertility, C. E. Thorne {Ohio Sta. Bui. 110., 

 pj). 91., pU. 11., (Igms. 8). — This is a detailed account of field experi- 

 ments with fertilizers carried on by the station from 1888 to 1899. 

 These experiments have been reported on from time to time in the 

 reports and bulletins of the station (E. S. R., 10, p. 919). 



Nearly 900 permanent plats, mainly one-tenth acre in size, have been 

 used. The work has been conducted at 5 different points in Ohio, viz, 

 (1) at the experiment station at Wooster, where the soil is a yellow 

 and somewhat sandy clay of glacial drift origin but largely modified 

 b}^ the soft sandy shales upon which it lies; (2) on the farm of the 

 Ohio State University at Columbus, where the soil is a much heavier 

 clay than that at Wooster, lying in part upon the Huron shale and in 

 part upon alluvial gravels; (3) near East Liverpool, Columbiana County, 

 on a thin clay underlaid by porous shale; (1) at the substation at 

 Neapolis, about 20 miles west of Toledo, on the yellow dune sands 

 which mark the ancient beach of Lake Erie, and (5) at a substation 

 near Strongsville, about 13 miles southwest of Cleveland, on a cold, 

 heavy, tenacious, white clay, underlaid by an impervious argillaceous 

 shale (Cuyahoga shale). Mechanical and chemical anal3^ses of 1 of 

 these soils are reported, the mechanical structure being shown graph- 

 ically. The fertilizers used have included dissolved Ijoneblack and 

 South Carolina and Tennessee acid phosphate, wheat bran, phosphatic 

 slag, and bone meal being also used to some extent as sources of phos- 

 phoric acid; nitrate of soda, sulphate of ammonia, dried blood, tank- 

 age, linseed meal, muriate of potash, and barnyard manure. 



"The crops employed in these tests are corn, oats, wheat, clover, timothy, and 

 p(3tatoes, soy beans being sometimes substituted for clover in case of failure to secure 

 a stand of the latter crop. The cereal crops — corn, oats, and wheat — are grown both 

 continuously and in rotation. Three rotations are in progress, one of com, oats, and 

 wheat, 1 year each, followed by clover and timothy, 2 years; one of potatoes, wheat,, 

 and clover, 1 year each; and one of corn, wheat, and clover, 1 year each. The 

 fertilizers are applied altogether upon the cereal and potato crops; the clover and 

 timothy follow as gleaners." 



To secure uniformity, machinery is used wherever possible for plant- 

 ing, distributing fertilizer, cultivating, harvesting, etc. 



The following summary of results of these experiments is given : 



"On soils formed chiefly from the argillaceous shales of the "Waverly series 

 phosphoric acid is found to be the constituent of fertility first required by corn, oats, 

 wheat, and potatoes; but the maximum yield has not been obtained until both 

 nitrogen and potash were also added. 



1710— No. 2 3 



