THE MANURING OF GRASS LAND 



[CH. 



many others appearing along with the delicate-looking quaking- 

 grass. 



The cause of the deterioration lies in the fact that neither 

 nitrate of soda nor sulphate of ammonia furnishes a complete 

 food for the plant ; phosphates are needed also, and on some soils, 

 usually the lighter ones, potash salts as well. 



257 

 214 



256 



4882 



822 



14 

 1778 



Unmanured 



986 



1770 



Plot 



Nitrate of Phosphates and Nitrate, phos- 

 soda only potash only phates and potash 



17 15 15 



D 



Grass 



Leguminous 



Others 

 (weeds, etc.) 



Fig. 9. Effect of artificial manures on the yield and composition of hay. 

 Rothamsted. 



(The figures give the actual weights in Ibs per acre obtained in 1914.) 



