81 



there is an increase of 6.08 tons per acre in field A and 8.38 tons per 

 jiere in field B. These data show a very large increase in yield due 

 to the application of the fertilizer at successive periods. 



Attention will next he directed to the application of 2,000 pounds 

 of fertili/er per acre at three different times. The average yield on 

 field A for the four years, with 2,000 pounds of fertilizer per acre in 

 three applications, is 22.71 tons and for field B 23.63 tons, which, 

 compared with two applications, indicates a loss of 0.70 ton per acre 

 on field A and 1.19 tons per acre on field B. For 1902 and 1905 

 there is indicated a loss of 1.98 tons per acre on field A and 4.21 tons 

 per acre on field B. These data would seem to indicate a loss in effi- 

 ciency of the fertilizer when applied at three successive intervals 

 instead of at two. 



EXPERIMENTS WITH THE REVISED-FORMULA FERTILIZER. 



The next experiment to be considered is that with 1,200 pounds of 

 revised-formula fertilizer for the years 1904 and 1905.* The average for 

 these two years on field A is 21.18 tons per acre and on field B 19.95 

 tons per acre. There is little difference in the character of the canes 

 produced on the two fields. When the 1,200 pounds of the revised- 

 fornmla fertilizer was used with an addition of 200 pounds of sodium 

 nitrate, the yield in 1905 was 21.75 tons per acre on field A and 25.93 

 tons per acre on field B. A comparison of these figures with the 

 tonnage obtained in 1905, when 1,200 pounds of the revised formula 

 alone were used, shows a considerable increase in the yield of field A 

 7 tons) and a very large increase in the yield of field B (4.90 tons). 

 The increase in the yield of field B, however, was at the expense of 

 the character of the juice, which is less rich in sugar than when no 

 sodium nitrate was employed. 



Where 200 pounds of sodium nitrate was used in two applications, 

 after the application of 1,200 pounds of the revised formula, the 

 comparisons can be made directly with the revised formula in one 

 application for the two years, 1904 and 1905. The average yield 

 on field A is 24.09 tons per acre and on field B 19.94 tons per acre, 

 with but little difference in the character of the juice. In this 

 instance it is seen that a considerable increase in the yield of field A 

 is obtained and no increase in the yield of field B. 



In the next case 1 ,200 pounds of the revised formula was used, with 

 the addition of 200 pounds of sodium nitrate used later in three dif- 

 ferent applications. In this case, comparing the yields for 1904 only, 

 there is a loss in field A of 0.6 of a ton w r hen the sodium nitrate was 

 used, and a gain of 2.05 tons in field B. These data are somewhat 

 conflicting and would seem to be indicate that there is no marked or 

 continued gain in yield by the addition of 200 pounds of sodium nitrate 



