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Subsoil of No. 14 : Soil particles larger than those of surface soil. This subsoil 

 consists of almost pure sand, yellow in color, which continues beyond the reach 

 of the soil auger (1.5 meters). 



Fertilizers. — Like most plants of the grass family sugar cane is a 

 rank feeder and rapidly impoverishes soils where it is grown unless special 

 care is taken to restore and maintain their fertility. If nothing but 

 the sugar in the cane were removed from the fields soil exhaustion would 

 not occur, but unfortunately under the ordinary process of harvesting 

 and milling cane, the leaves are stripped off, the stalks entirely removed 

 and the bagasse is burned as fuel instead of being returned to the soil. 

 Cultivation of the stubble is very difficult unless the leaves and tops are 

 burned when dry, which practice is very common in all sugar-growing 

 countries. Where the cane is thus removed and the trash on the field 

 burned there is a constant loss in the soil of nitrogen, phosphoric acid, 

 and potash. The burning of the trash causes a total loss of the nitrogen 

 but the phosphoric acid and potash are partially recovered in the ash 

 resulting from the burning. The mechanical effect of leaving the trasli 

 to rot on the field is very beneficial by increasing the total amount of 

 humus in the soil. There are a number of ways of restoring and main- 

 taining the fertility to the lands, and at least three of these should be 

 constantly used by all growers of this crop. As much of the trash and 

 leaves as possible should be left on the ground to decay, leguminous crops 

 should be planted alternately with the sugar crops for the special pur- 

 pose of restoring the nitrogen elements of fertility in the soil. The 

 common practice of growing mungos on sugar land in Negros is a very 

 practical method for use in the Philippines. There should be a more 

 liberal use of commercial fertilizers. Duggar ' states that a good cane 

 fertilizer should contain nitrogen, phosphoric acid, and potash in about 

 the following proportions : Nitrogen, 4.5 per cent ; available phosphoric 

 acid, 8 per cent; potash, 4.5 per cent. 



Conner^ gives a formula containing 5 per cent nitrogen, 8 per cent 

 available phosphoric acid, and 10 per cent of potash. 



This should be applied at the rate of about 600 kilos per hectare in 

 furrows by the side of the cane as soon as the cultivation is begun, and 

 additional applications, in smaller or larger quantities, will prove quite 

 profitable if made during the active growing period of the cane. In the 

 dry portions of the Hawaiian Islands there is a tendency to make very 

 heavy applcations of nitrate of soda dissolved in irrigation water and run 

 over the fields at intervals of three to four weeks. In the districts of 

 heavy rains, like Hilo, sulphate of ammonia is used on account of its not 

 leaching out of the soil. Lime as a fertilizer will prove valuable on 

 the heavy clay soils of the Philippines, particularly when they are first 



' Southern Field Crops. 



- Philippine Agricultural Review. Volume IV, page 50. 



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