CANE SUGAR. 



Reverted phosphate is the name given to a form of lime phosphate insoluble 

 in water, but soluble in ammonium citrate solution, and which is valued at as 

 high a figure as water soluble phosphoric acid. Superphosphates have a 

 tendency on storage to pass into 'reverted phosphate,' and this material is 

 manufactured and sold under the name of 'precipitated phosphate,' containing 

 from 35 per cent, to 40 per cent, of phosphoric acid soluble in ammonium 

 citrate. 



Potash manures. Potash is applied in cane-producing countries as pure 

 sulphate containing about 48 per cent, of potash ; the chloride is also occa- 

 sionally used. Kainit and other crude salts find a limited use in mixed 

 manures. 



Practice of Cane Manuring in different Countries. 



In Java and also in Demerara readily available nitrogen, chiefly in the form of 

 ammonium sulphate, is to a large extent the only artificial manure applied. 

 In Java it is claimed that the rotation there followed puts on the soil a 

 sufficiency of other elements of plant food for the cane crop ; this is largely 

 due to the water used in growing the rice holding in suspension a large 

 quantity of silt, which is deposited on the land. 



In Demerara it is also frequently the custom to apply up to 10 cwt. of 

 basis slag phosphate to the plant canes, especially if analysis by Dyer's citric 

 acid method shows a deficiency in this element. On the heavy clay soils it is 

 exceptional to find a deficiency of potash, notwithstanding the heavy drain 

 made on this element by the continuous crop of cane. 



In Hawaii, where the largest yield of cane is obtained, relatively 

 enormous quantities of manure are employed; nitrate of soda is employed 

 largely on the irrigated plantations in the districts of little rainfall, and this 

 material, as well as sulphate of ammonia much less frequently, is used in the 

 spring of the second growing season ; the application reaches up to 400 Ibs. 

 per acre. 



In the Hawaiian Islands the climatic conditions are such that it is 

 possible to obtain a period of growth from planting to harvest up to 24 

 months ; hence there are two growing seasons and the application of manures 

 before each has been found to be very beneficial. The practice is generally to 

 use mixed fertilizer in the first growing season and nitrate in the second. 



In that district also a cold spell is annually encountered, when a check to 

 and yellowing off of the cane occurs ; this is probably due to a cessation of 

 the activities of the nitrifying organisms in the soil. It has been found by 

 experience that the application of nitrates at this time has a very beneficial 

 effect on the growth of the cane. 



In addition a complete fertilizer containing on an average 7 per cent, to 

 10 per cent, each of nitrogen, phosphoric acid and potash is applied; the 



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