THE MANURING OF THE CANE. 



In a Sugar Plantation there is little Drain on the Soil. 



A sugar estate ships only carbon, hydrogen and oxygen, none of which are 

 obtained from the soil ; the whole of the nitrogen and ash is contained in the 

 by-products leaves, tops, press cake, molasses, &c., and if these are returned, 

 the fertility of the soil should remain permanently unimpaired. This generaliza- 

 tion requires some modification. Few estates make white sugar, and the raw 

 sugars contain some part of the ash and nitrogen; in other cases molasses are 

 sold off the estate, and in the combustion of the megass the nitrogen and some of 

 the potash are lost ; loss of the first-named material also occurs in burning off 

 trash. To these causes of soil impoverishment must be added that due to 

 drainage waters ; notwithstanding, the agricultural cycle of a sugar estate is 

 very different from that of a farm where grain, roots, milk and live stock are 

 removed. 



Bacteria in Relation to the Soil. This subject, which is one 

 of the most important problems of the day, can only be touched on in bare out- 

 line. In the first place, organic matter buried in the soil is acted on by both 

 bacteria, and by fungi; a product (humus), richer in carbon and poorer in 

 oxygen than the original material, eventually results. In the presence of air 

 this action proceeds faster, and is more complete, than in its absence ; hence 

 the availability of organic matter, cane trash for example, and of manures 

 such as cotton seed cake, is more rapid in well tilled than in unworked soils ; 

 similarly, in stagnant soils, there is an accumulation of organic matter, as in 

 bogs and peaty soils. The products formed by the action of the soil organisms 

 are of an acid nature, and unless some base, such as calcium carbonate, is 

 present in the soil to neutralize the acids formed, bacterial action eventually 

 ceases, and what decay then occurs is due to fungi; in this case, too, the 

 decomposition is not so complete, and there is a tendency to the accumulation 

 of organic matter, in the soil. The form in which this organic matter occurs 

 may not be of benefit to plant life ; soils formed under these conditions may 

 contain large quantities of nitrogen, and yet be unproductive, until by tillage 

 and aeration, such a bacterial flora is obtained that the supply of nitrogen is 

 offered in an assimilable form. 



A number of years ago a preparation of certain micro-organisms was put 

 en the market under the name of alinit ; it was stated to consist of a pure 

 culture of an organism known as Bacillus ellenlaclienns, and to it was attributed 

 the property of fixing nitrogen from the air ; it was observed to benefit soils 

 containing much humus, and to be beneficial in conjunction with slow acting 

 nitrogenous manures ; its action was probably due to its initiating bacterial 

 action on soils where the organisms, associated with the decay of organic matter, 

 were absent. The use of this preparation has now merely an historical interest. 



The possibility of the utilization of the nitrogen of the atmosphere by the 

 higher plants forms one of the world's classical polemics.* It is at the present 



* The fixation of nitrogen by the leguminosse is discussed under a separate caption. 



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