Influence of Manures on Yield of Timothy Hay. 



265 



The results also show that, within certain limits, the effect of decreasing 

 the amount of phosphorus without changing the amounts of the other 

 constituents is to increase the yield, while the same effect is produced by 

 increasing the amount of nitrogen without changing the other constitu- 

 ents. The following table brings out this point: 



TABLE V 



Plat 

 No. 



721 

 722 

 724 



72.S 



Treatment 



160 lbs. 



80 lbs. 

 320 lbs. 

 160 lbs. 



80 lbs. 

 640 lbs. 

 320 lbs. 



80 lbs. 

 640 lbs. 

 320 lbs. 



80 lbs. 

 320 lbs. 



nitrate of soda ) 



muriate of potash >■ 



acid phosphate \ 



nitrate of soda "j 



muriate of potash >■ 



acid phosphate j 



nitrate of soda ) 



muriate of potash > 



acid phosphate '. ) 



nitrate of soda ) 



muriate of potash > 



acid phosphate ) 



Average 



apparent 



increase 



for 3 



years 



lbs. 

 2,632 



2,183 



3.915 

 4,192 



It will be noticed that for the three years during which the experiment 

 has been conducted, Plat 722, which received the maximum amount of 

 phosphorus, has yielded considerably lower than Plat 721, on which the 

 phosphorus was reduced one-half, the other constituents remaining the 

 same. It will also be noticed that Plat 724, which received the same 

 amount of phosphorus as Plat 722, but twice the amount of nitrogen, 

 gave a large increase over Plat 722 ; and, finally, that Plat 725, on which 

 the amount of phosphorus was again reduced one-half, while the other 

 constituents remained the same as on Plat 724, gave a continued increase. 

 The evidence seems to point to the fact that Plat 725 received the 

 fertilizing elements in a more favorable proportion for maximum yields. 



INFLUENCE OF SEASON ON YIELD OF HAY 



That the nature of the growing season as regards temperature and 

 rainfall is a very potent factor in influencing the growth of crops and the 

 relative action of the various fertilizing constituents has been recognized 

 for some time. The yield of hay on the plats under consideration for the 

 three seasons of 1905, 1906 and 1907, illustrates this fact clearly. The 



