24 



(6) Doubling the nitrogen gives the same tonnage as the " no nitro- 

 gen ' plats. Compare plats Nos. 13 and 1(>, both of which give 4 tons 

 less per acre than the normal ration. The general trend of the experi- 

 ments points to the need of a very small application of nitrogen; pos- 

 sibly none would have been more profitable, but 20 pounds per acre is 

 certainly sufficient. 



(7) Doubling the acid phosphate gives a gain of 13 tons per acre 

 over the "no acid phosphate" plat and a gain of 3 tons over the 

 normal ration. In general the need of a larger application of phos- 

 phoric acid is shown, and probably about 200 pounds of this fertilizer 

 per acre would be the most profitable proportion. 



(8) All results indicate that the following formula for a fertilizer 

 would give the best results on such land as Field A, on which a heavy 

 growth of velvet beans had been grown and plowed under the previous 

 year: 



Pounds. 



12.5 per cent acid phosphate 1, 600 (200 pounds phosphoric acid=ll.l per cent). 



Nitrate of soda 100 (nitrogen = l per cent). 



Muriate of potach 100 (50 pounds actual potash =2. 72 per cent). 



