12 T H E C U B A R E V I E W 



BY-PRODUCTS OF SUGAR MANUFACTURE 



Bij Cleve. W. Hinen, M. S., Station Superintendent 



In various lines of manufacturing there are certain by-products which, years ago, consti- 

 tuted a waste and great loss, but which now under modern methods have become in many 

 cases of considerable importance. 



This is especially true with the sugar industry. Extreme care and attention is required to 

 keep the balance on the right side of the ledger, and often the proper handling of the by-pro- 

 ducts forms the deciding factor between success and failure. In order to build up a great sugar 

 industry in these Islands, more attention must be given to the details of the work, and many of 

 the present losses must be turned into profits before great progress can be expected. 



Cane Tup.s and Inrush. 

 t'First in the series of by-products in the manufacture of sugar, comes cane tops. The 

 amount of this material produced per hectare will depend upon various factors, including the 

 variety of cane, its stage of maturity, etc. The less of these tops, of course, that may be pro- 

 duced for a given amount of cane, the better it will l)e for the growers, nevertheless they have 

 a good feeding value if jiroperly handled. 



Professor Dodson, director of the Louisiana Experiment Station, states that he found cane 

 tops to have the following composition: Per cent. 



Protein 1-53 



Fat 0.41 



Carbohydrate 15.62 



Fiber 8 . 87 



Water 71 . 50 



Ash 2.07 



The fiber content would be slightly higher and the water content lower, for tropical cane 

 since maturity is completely reached before harvest begins. It may be seen from the above 

 analysis that this makes a most excellent feed for work animals. Certainly greater advantage 

 should be taken of this feeding stuff than is usually done, since there is a scarcity of pasturage 

 near the end of the harvest season and the animals become needlessly thin on account of lack of 

 feed. At present very little of this material is utilized, Ijut instead is Inirned on the field with 

 the rest of the trash. If the tops are removed and used as a stock feed, only the leaves and 

 pieces of stalk remain, and these make a good fertilizer for cane lands. 



It is the general custom in these Islands to burn all of this material as soon as the crop is 

 harvested. The object of this burning is to destroy any insects that may be present, as well 

 as to facilitate subsequent cultivation. In the writer's opinion neither of these reasons is 

 sufficiently well based, since in this country large numbers of troublesome cane insects are not 

 found. If they were present in sufficient quantities, the trouble could be handled by placing 

 the trash between the rows and properly treating it before plowing it under. This should be 

 the method of disposing of the trash at all times. In this manner the waste material could be 

 utilized, and the organic matter would be even more valuable than that contained in many of 

 the commercial fertilizers. The nitrogen contained, which amounts to from 0.5 to 2%, would 

 be practically all saved, while with the burning method this is completely lost. 



In Louisiana, cotton-seed meal forms one of the principal nigrogenous fertilizers for cane 

 lands. This material costs from 50 pesos to 75 pesos per ton and Dr. Stubbs, in his research, 

 found that the trash burned from each ton of cane caused a loss of nitrogen equal to that con- 

 tained in 27 pounds of cotton-seed meal. Besides this loss of nitrogen encountered in the 

 burning of the trash, the organic matter which would later form humus is completely destroyed. 

 Soils would retain moisture better during the dry season and be more easily handled if the con- 

 servation of organic matter were given greater attention. There is also a great injury don to 

 the remaining stumps and top roots by this burning which is very detrimental when the field 

 is to be used for a ratoon crop. Where cane is badly infested with destructive insects, it is 

 quite another thing. This again brings up the fact that the cane points should be treated with 

 chemicals before planting, in order to complete the work of destroying these insects. 



