IMPROVEMENT OF THE SUGAR CANE, 11g 
/ 
Mixed minerals (superphosphate of lime and potash 
salts) applied without nitrogen gave no increase. Other 
series of experiments in which either phosphates or 
potash salts were applied to manurings yielding nitrogen 
and potash or nitrogen, and phosphates respeétively, 
shewed that whilst phosphoric acid was a necessary con- 
stituent of cane manures to obtain maximum effeéts, 
potash produced but little increase that could be traced to 
its direét manurial influence, and that the beneficial effe€&ts 
of both these constituents were far less marked than 
those of the nitrogen in the manures. Dr. STUBBS con- 
sidered from the results of these experiments that phos- 
phoric acid when used at or after planting should bein a 
soluble state, and that if insoluble phosphates were ever 
used they should be applied sometime in advance of the 
planting. 
During the five years 1890-1894 at Audubon Park, 
confirmatory results were obtained ; thus :— 
Nomanure ... Ly ...21'8 tons of canes per acre. 
Mixed minerals and 24 lbs. Nitrogen 27° __,, es és 
9? 9 33 48 33 ” 28° 33 33 ” 
This series of experiments loses much of its value 
from the fact that the land had to be first levelled, and 
thus whilst some parts were of fertility beyond the normal, 
others were of less fertility owing to the removal of much 
of the top soil. 
The conclusions arrived at with regard to phosphoric 
acid and potash, as far as I can ascertain from the 
reports in my possession, were very similar to those 
deduced from the previous trials at Kenner, 
During the experiments, trials were made with nitrogen 
derived from different sources, and the following shows 
