18 MANUAL FOR SUGAR GROWERS. 



living animals whose remains give rise to this kind 

 of soil. 



The knowledge of the conditions influencing fer- 

 tility constitutes a large portion of the science of 

 agriculture ; among the chief of these conditions 

 are : 1. Weather, with its supply of rain, sunlight, 

 and warmth. 2. Plant-food required by the pai-tic- 

 ular crop under consideration, — in this case, the su- 

 gar-cane. 3. The condition of the land as regards 

 what agriculturists usually know as heart. 



In order to constitute what is known as good 

 condition or heart, several things are necessary. It 

 is essential that the soil be sufficiently loose and 

 friable, that the roots may penetrate it with ease ; 

 the soil must also possess the power of retaining 

 sufficient moisture to sustain the life of the plant, 

 and at the same time must not retain too much, or it 

 will become waterlogged, when most plants will re- 

 fuse to grow in it. It is essential, too, that the soil 

 contain air, for plants will only grow in the pres- 

 ence of air and will refuse to penetrate a soil whose 

 pores are devoid of it, as in the case of wet or under- 

 drained soils, where the growth is always checked. 

 The influence of air upon root-growth is often well 

 shown when roots obtain access to drains, the growth 

 often being so abundant as to choke the drains. 



These three conditions are favourably developed 

 by the operations of ploughing, digging, or forking, 

 the soil being loosened, the particles separated from 

 each other, the capacity for retaining air and moist- 

 ure much increased, at the same time that the re- 

 moval of excessive moisture is facilitated. 



