FERTILIZER EXPERIMENTS WITH SUGAR CANE ^ 



By Jose Mirasol y Jison 

 (From the College of Agriculture, Los Bancs) 



TWO TEXT FIGURES 



Sugar cane is an exhausting crop on any soil. According to 

 Maxwell,^ a ton of sugar, when the trash of the cane is returned 

 to the soil, removes from it 12.7 pounds (5.77 kilograms) of 

 nitrogen, 35.3 pounds (16.45 kilograms) of potash, and 8.2 

 pounds (3.72 kilograms) of phosphoric acid. An 8-ton sugar 

 crop per hectare would then remove 46.2 kilograms of nitrogen, 

 131.5 kilograms of potash (K.O), and 29.8 kilograms of phos- 

 phoric acid (PoOJ. The common practice in the Philippines 

 is to plant cane after cane on the same field without restoring 

 the plant food removed by the crops. The world's experience 

 is that no one crop can be continuously and profitably grown 

 on the same unfertilized soil, no matter how rich it was at the 

 beginning. In Queensland, Maxwell analyzed some virgin soils 

 and some that were continually cropped with cane. A com- 

 parison of his results showed a loss of 31 per cent of nitrogen, 

 42.2 per cent of potash, and 37.2 per cent of lime. Considering 

 that the sugar produced in the Philippines in one year (1916) 

 amounted to 374,000 tons from 179,761 hectares of land,^ it is 

 apparent that the question of maintaining the fertility of our 

 sugar lands is of national importance. 



The use of commercial fertilizers for cane was recently in- 

 troduced into the Philippines. But the failure of some farmers 

 in their attempt to increase the yield of cane by the use of 

 commercial fertilizers has created an atmosphere of prejudice 

 against their use among local cane growers. This condition is 

 rather unhappy. As a general proposition there is nothing 

 wrong about the use of commercial fertilizers. The failure of 

 the farmers who tried to use them was due to a lack of infor- 

 mation regarding the manurial requirements of their soils, to be 



^ Portion of graduation thesis for the degree of Master of Science, No. 3. 

 Received for publication January 31, 1918. 



' Sugar Cane. Published by German Kali Works. 



' This figure was obtained from the Bureau of Agriculture booth stand 

 at the February, 1917, Philippine Carnival. 



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