74 MANURES AND MANURING. 



It is commonly said that Coffee is an unusually ex- 

 haustive crop, but the exhaustion of the soil consequent 

 upon Coffee culture is only the result of the peculiar con- 

 ditions under which the industry is prosecuted rather 

 than of the nature of the plant itself. Better than any 

 amount of artificial manuring is the retention of the 

 naturally rich surface soil by the effective prevention of 

 wash as a secondary adjunct; however, judicious manur- 

 ing will prove highly beneficial, and even necessary in 

 almost all cases after the first or two. But it is impos- 

 sible to lay down any hard and fast rule for manuring, the 

 most that can be done is to indicate the essential elements 

 of coffee soils, the best artificial substitutes and the best 

 methods of applying these substitutes. The best coffee 

 soils appear to contain about 15 per cent, of combined 

 iron and alumnia, the iron, if as red oxide may amount to 

 about 20 or even 30 per cent, being a good absorbent of 

 fertilizing constituents, but the alumnia should not 

 exceed 10 per cent. Lime is also an essential, which 

 must be supplied, if wanting in the soil; this is too often 

 overlooked in the anxiety to furnish stimulants. The 

 percentage of organic matter may be too high, it should 

 represent only about 0.2 to 0.3 per cent, of nitrogen, so 

 that the best average manure for supplying nitrogen and 

 potash is well-rotted dung, but its frequent application 

 should be accompanied by a little lime unless the soil is 

 already very rich in that constituent, for, without the 

 presence of lime, the shrubs will not receive the full bene- 

 fit of the nitrogenous principles, but its use in a tropical 

 climate must be governed by caution. Thoroughly fer- 

 mented coffee pulp is also a useful manure, but it is only 

 half as valuable as dung and costs more to apply, it 



