THE MANURING OF THE CANE. 



1. The advantages of a rotation are obtained. 



2. The deep tap-roots of leguminous plants bring available plant food 

 from the subsoil to the surface soil. 



3. The ill effects of a naked fallow are avoided. 



4. The interposition of a crop other than cane will act as a prophylactic 

 towards fungus diseases and attacks of insects, for if the habitat of these 

 parasites be removed for any length of time it must result in their diminution 

 or disappearance from lack of food. 



In certain quarters, notably in Mauritius, after land has been under 

 Ieguminosa3 for a time, it is prepared for cane cultivation again by burning off 

 the greeD above-ground crop. This process would seem to destroy the very 

 benefits to obtain which the green manure was planted. Planters who follow 

 this system claim as good a result as when the green crop is buried, and point 

 to the saving in expense. To obtain definite information as to this process the 

 writer grew on small plots equal to 5^0- of an acre crops of the Phaseolu 

 lunatus* and Mucuna utilis. The results calculated out to an acre were as below. 

 The crop in both cases was six months between planting and harvesting, which 

 was done when the seeds were ripe. 



It will be seen that about 80 per cent, of the manurial value of the crop 

 was contained in the green crop ; if this is burnt off the nitrogen is lost, but 

 the potash and phosphoric acid remain in a form readily available for the 

 coming crop of cane. The economy of burning off the green crop and losing 

 the nitrogen is comparable with the practice of burning off trash ; in any case 

 there is obtained a large amount of mineral plant food brought up from the 

 subsoil. The high nitrogen content of the bean straw, and the possibility of 

 using this material as bedding for plantation stock, and thus both conserving 

 it and obtaining a pen manure rich in nitrogen, is worthy of notice. 



*Pois d' Archery in Mauritius; the 'Java' and 'Rangoon' beans of commerce. 



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