seven times as much as the average of plots 1 and 2. 

 All were profitable, although the limit of net profit was 

 reached with an application of 300 pounds per acre. 

 That is, it seems that beyond that point the season and 

 climatic conditions rather than Nitrogen became the 

 limiting factors, when soils were supplied with enough 

 phosphoric acid and potash. The application of Nitrate 

 of Soda was profitable in all cases, though varying with 

 the amounts applied. 



The farmer naturally desires to secure the greatest 

 net profit. On land of this sort, therefore, it would be 

 necessary for him to apply 300 pounds per acre; for a 

 large field this dressing would seem to be rather expen- 

 sive, taking into consideration the possible risk due to 

 unfavorable seasons. In many cases, too, the produc- 

 tive power of the soil may be greater than was here 

 found to be the case, when a less quantity of Nitrate of 

 Soda would meet the needs of a maximum crop. 



The experiment gives suggestions on this point, 

 also. Averaging the yields obtained from the use of 

 Nitrate, it is found that the application of 100 pounds 

 of Nitrate increased the yield by nearly 800 pounds. 

 Taking this to be a fair guide, as to what may be ex- 

 pected from the application of Nitrate, the amounts to 

 be applied would be in proportion to the difference 

 between what the farmer estimates to be his average 

 yield and the possible production in his neighborhood. 

 For example, assuming that the average yield would be 

 3,000 pounds, without Nitrate, and the maximum yield 

 5,000 pounds with Nitrate, an application of 250 pounds 

 per acre would enable him to reach his maximum yield, 

 If, on the other hand, his estimated yield, without 

 Nitrate is 2,000 pounds, and his estimated maximum is 

 3,000 pounds, then the application of 125 pounds of 

 Nitrate of Soda per acre would supply all the needed 

 Nitrogen to make this yield. In either case, the Nitrate 

 would be used to quite as good advantage, as was shown 

 in this experiment, and the results profitable in both 

 cases, though, as in the experiment, the larger, yield 

 would give the largest net returns. It is more than 

 likely that on average soils an application ranging from 

 125 pounds to 200 pounds of Nitrate of Soda per acre 



