SUGAR-CANE SIRUP MANUFACTURE 5 
responds well to this treatment, sirup from cane which has received 
heavy and direct applications is inferior—-dark red in color and poor 
in flayor. If, however, the heavy application of barnyard manure is 
made to the crop preceding the sugar cane, the quality of the sirup 
is not seriously affected, and the yield of cane is greatly increased. 
Farmers who have much barnyard manure available and grow sweet 
potatoes may well plan the rotation so that sweet potatoes precede 
the sugar cane, the barnyard manure being applied to the sweet 
potatoes. What has been said concerning the application of barn- 
yard manure is true also of cowpenning the land. 
It is not unusual for farmers to think of cane growing on the richer 
sandy-clay loam lands as a means of building up their land for the 
crops that are to follow it, rather than to think of growmg other 
crops to build up the land for cane. Heavy applications of com- 
mercial fertilizer are accepted as an unavoidable expense connected 
with cane growing, calculated, however, to give increased returns 
from the other crops grown during the next year or two. When the 
land is more nearly exhausted, cotton, for which a very rich soil 
is not desirable, is often planted. When the land has become too 
ereatly exhausted for cotton, cane may be planted again. Ii barn- 
yard manure is available and heavy applications of it have not been 
made to the crop preceding the sugar cane, moderate quantities only 
should be apphed to the cane. 
Not many sugar-cane-producing farms where sirup is made have 
enough barnyard manure to maintain fertihty, so commercial fertil- 
izers must be used. Practically all soils in the sirup sections of the: 
Southern States require applications of nitrogen and phosphoric acid. 
Although it has had but little effect when applied in Louisiana, potash 
is now generally used in fertilizer mixtures in the eastern Gulf States. 
With the increasing demand for it as a stock food and the decreasing 
supply because of the boll weevil, cottonseed meal, which has been 
the favorite nitrogenous fertilizer (ammoniate), is giving way to 
tankage, dried blood, fish scraps, etc., for a slowly available ammoni-- 
ate, and to the more concentrated ammoniates, sulphate of am- 
monia, and ‘nitrate of soda. The phosphoric acid fertilizer almost 
universally used is the acid phosphate, with about 16 per cent of 
available phosphoric acid. Sulphate of potash is the best form of 
potash. 
VARIETIES OF CANE 
Only the earliest maturing of the sugar-cane varieties known are 
adapted to the Southern States, where the growing season is limited 
to 8 to 10 months. A large yield of stalks is, of course, one of the 
most important qualities sought. A high percentage yield of juice 
in the stalks ( a low fiber content) is eed A juice having a high 
percentage of solids—that is, a juice of high spindle (saccharometer) 
test—yields more sirup than one low in total solids. 
For sirup making, it is desirable that a portion of the sugars present 
be in the form of invert sugar, which consists of the two sugars 
dextrose and levulose. Then the sirup can be boiled with no granula- 
tion (crystallization of sugar) to a higher density than would be possi- 
ble otherwise. Stalks of light color ade and yellow) almost always 
yield a sirup of lighter, more attractive color than darker stalks. _ 
The coloring matter of cane juice is derived from the soluble pig- 
ments in the rind of the cane, the substances in the juice which form 
dark products with iron, and dark substances produced by decom- 
