THE MANURING OF THE CANE 85 



oy phosphates. The lack of response to mineral manures is attributed to 

 the beneficial effect of the very large quantity of silt annually brought down 

 in the water used on the rice crop, which precedes that of the cane. 



The Practice of Cane Manuring in Different Countries. — In Java and also 

 in Demerara sulphate of ammonia is often the only material used. The 

 average quantity employed in Java^^ is 350 lbs. per acre, with variations 

 from 250 lbs. to 450 lbs. In Demerara the quantity used is rather less, and 

 seldom reaches 300 lbs. per acre. A number of years ago oil-seed cake manure 

 was used to a great extent in Java, but its use has been given up almost 

 entirely in favour of the more readil}- available form. 



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

 basic 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, notmthstanding 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 lbs. 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 yellonnng off of the cane occurs ; this is probably due to a cessation of 

 the activities of the nitrif}dng 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 

 proportions of these ingredients are altered to correspond with the analysis of 

 the soil. Up to 1,000 lbs. per acre of such a fertilizer may be applied, 

 although 600 lbs. is a more usual dressing. Basic slags are but little, if at 

 all, used. 



In Mauritius and Bourbon large quantities of pen manure were (previous 

 to the extended use of mechanical traction) employed, and the plant canes 

 seldom received any other fertihzer. For ratoon crops a complete mixture, 

 similar to that quoted above as used in Hawaii, is employed, but in a much 

 smaller quantity. 



In Louisiana, chiefly owing to its local production, cotton-seed meal forms 

 the chief source of nitrogen, and superphosphate forms the source of phos- 

 phoric acid. Owing to the abundance of potash in the soil this element is 

 seldom necessary, and its action in retarding maturity is a reason against its 

 use in such a climate. 



In Egypt nitrate of soda is the chief source of readil3^ available nitrogen, 

 applications being made to the young cane after an irrigation. The Nile 

 water used in irrigation brings into the soil a certain quantity of plant food, 

 and the rotations followed also reduce the necessity for such heavy dressings 

 of manure as are used elsewhere. A peculiar manure and of small value. 



