No. 4.] 



MANURIAL PROBLEMS. 



179 



yet progressed far enough to justify drawing definite con- 

 clusions at this time. The results secured are in brief as 

 Ibllows : — 



Experiment concerivhig the Ainnunts of Nitrogen to ^ise in 

 T<yp-drefiKing Grasn TAind.* 



The land upon which the exporiniont was conducted had 

 been limed at the rate of 1 ton of slaked lime per acre in 

 1<S1)7. In the spring of 181)8 barley was sown, and with it 

 the following quantities of clover and grass seed, viz. : — 



Common red clover (^Trifoliiim j^fatense L.), 



Timothy (rhleum jiratense L.), 



Red-top {Agroslis alba var. vulgaris Thurb.), 



Pounds per Acre. 



7.5 



15.0 



7.5 



"Total" phosphoric acid (P.2O5) has been supplied in acid 

 phosphate as follows : — 



The amount was increased in 1900 by virtue of using a 

 higher-grade acid phosphate, but it was reduced again in 

 1901. Upon analyzing the crop of that year, whereby the 

 small amount of phosphoric acid removed was definitely 

 ascertained, we ^vcre led to the belief that 65 to 90 pounds 

 per acre woidd probabl}^ be sufiicient, or an amount that 

 would be supplied by 500 to 600 pounds of the grade of 

 acid phosphate containing about 13 per cent of "available" 

 phosphoric acid. 



The equivalent of actual potash supplied in muriate of 

 potash during the experiment has been as follows, viz. : — 



* A full history of the manuring and treatment of the plots embraced in this 

 experiment is to be found in Bulletins Nos. 57, 71, 82 and 90 of the Rhode 

 Island Agricultural Experiment Station. 



