17 



This better quality of sirup would naturally command a better 

 price in the market; therefore the actual financial difference in the 

 results between the two lields would not be so great as would appear 

 from a study of the tonnage data alone. In comparing the yields 

 from Fields A and H it must not be forgotten that the actual fertility 

 of Field 1) is greater than Field A. because it has been a shorter time 

 under cultivation, and in addition to this the crop in Field I> was pre 

 ceded by a leguminous crop, a nitrogen gat hei er which was plowed 

 under, thus adding a large amount of available nitrogen to the sue 

 ceeding crop. In Field A, on the contrary, sweet potatoes had been 

 grown, and this crop adds nothing to the fertility of the soil, but 

 rather tends to diminish it. 



The basic data for comparison are found in Plat 24, to which no 

 fertilizer i \yas applied. The yield of cane per ton on this plat was 1). \-2 

 tons in Field A and 12 tons in Field B. It is to be regretted that one 

 or two additional check lots were not provided, since the difference in 

 yield in the two plats 24 in Fields A and B is not so great as one 

 would expect. In other words, although Fields A and I> were treated 

 exactly alike, if you should add only 3 tons per acre to the yield of 

 Field A you would not reach the yield of Field B in many instances. 

 This fact leads to the -inevitable conclusion either that the two plats 24 

 in each tield do not afford a sufficient comparison, or else the previous 

 treatment of Field B made it unusually well adapted to utilize to the 

 very best advantage the plant foods added in the fertilizer. In another 

 experiment there should be at least four unfertilized plats in each 

 field. 



Without going over the data in detail it will be interesting to com- 

 pare the yields per acre on the plats which were t reated with the same 

 amount of fertilizer, but applied differently, namely, 1, '1 :!. and 4; 

 5, (>, 7, and 8; and 9 and 10. It will be evident at once that the nor- 

 mal fertilizer suggested is the best combination of fertilizing material 

 with which experiments were made. The yields per acre, the per- 

 centage of sugar, and the purity of the juice are the data on which our 

 judgment must be based. 



On Field A with 1,200 pounds of normal fertilizer the average yield 

 was 2<>. 12 tons per acre on plats Nos. 1 to 4, inclusive. On plats Nos. 

 5 to 8, inclusive, with 2,000 pounds of the normal fertilizer we see 

 that the average yield was 22.96 tons per acre, while on plat No. 24, 

 to which no fertilizer was applied, the yield was 9.12 tons per acre. 

 These data show that on Field A the application of the normal ferti 

 lizer more than doubled the yield when applied at the rate of 1,200 

 pounds; while with the use of 2,000 pounds per acre the yield was 

 increased almost exactly 152 per cent. Where the application dropped 

 to 800 pounds per acre the average yield was also very satisfactory, 

 being almost exactly double the yield without fertilizer. The appli- 

 24060 No. 7503 2 



