134 TIMEHRI. 
amount of readily available nitrogen either naturally 
present in the soil or added in the manures applied. 
2. When applied in quantities containing not more than 
from forty to fifty pounds of nitrogen per acre, sulphate 
of ammonia and nitrate of soda are, on the majority of 
soils, equally effe€tive as sources of nitrogen, but when 
the unit of nitrogen in these substances is of equal money 
value, it is, as a rule, more economical to apply the former 
rather than the latter. Dried blood and similar organic 
manures in which the nitrogen only slowly becomes 
available are of distinétly lower value as sources of 
nitrogen than the two above mentioned. 
3. Under ordinary condition of soil and climate and 
the usual range of prices for sugar, it is not advisable 
to use more than 2 cwts. of sulphate of ammonia, or its 
equivalent, 23 cwts. of nitrate of soda per acre. 
4. If circumstances arise which render it desirable 
to obtain the maximum yield per acre by addition of 
nitrogen in quantities in exczss of about 50 Ibs. per acre, 
sulphate of ammonia ought always to be seleéted as the 
source of nitrogen. } 
5. Pra€tically on all soils manurings with nitrogen re- 
quire to be supplemented by applications of phosphoric 
acid, The most effective forms of phosphoric acid appear 
to be superphosphate of lime and slag phosphate meal. 
Mineral phosphates are of distinctly lower value and are 
not effective unless applied in quantities far in excess in 
value of those required of either superphosphate or slag 
phosphates. Asa rule, the phosphates should be applied 
only to plant canes, their manurial a€tion on ratoon canes 
being but limited. 
6. On some soils the application of potash salts in 
a 
