GRASS FOR HAY 



21 



Use of' Nitrogenous Manures alone 



Three of the plots — 17, 5, and 1 — show the effect of the long-continued 

 use of nitrogenous without any mineral manures, Plot 5 has been receiving 

 86 lbs. of nitrogen as ammonium-salts. Plot 17 half the quantity of nitrogen 

 in the shape of nitrate of soda, and Plot 1 the same half quantity of 

 nitrogen as ammonium-salts, though on this plot dung was applied in each 

 of the first eight jears of the experiment. It is very evident when a 

 nitrogenous manure is used alone for grass, nitrate of soda is far more 

 effective than the ammonium-salts ; e.g.^ on Plot 17 it has given an 

 average crop of 35 cwt. against 26 cwt. produced by double the quantity 

 of nitrogen in ammonium-salts on Plot 5. 



Mineral Manures used alone 



On three of the plots no nitrogenous manures have been applied since 

 the beginning of the experiments. On Plot 7 a complete mineral manure. 



Without Nitrogen. 



With Nitrogen. 



Cwt. per Acre 

 50 



Fig. 6. — Effect of the various Ash constituents with and without Nitrogen on the 

 produce of Hay per acre. Average over 47 years (1856-1902). 



Plots 3 and 12. Unmanured. 



Plot 4-1. Superphosphate. 

 Plot 8. Minerals with Potash. 

 Plot 7. Complete Mineral Manure. 



Plot 4-2. Super, and Aram. -salts = 86 lb. N. 



Plot 10. Minerals (without Potash) and 



Aram, -salts = 86 lb. N. 



Plot 9. Coraplete Mineral Manure and 



Amm. -salts = 86 lb. N. 



