AGRICULTURAL DRAINING. 47 



cultivated land and grass land also in warm climates we 

 see satisfactory results follow this kind of improvement. 

 It not only tends to make the soil workable and capable of 

 bearing crops and sweet grass during wet seasons, but in 

 dry seasons the drained land holds out better than 

 undrained land of the same character, a change due to the 

 powers of drained land to absorb moisture from the damper 

 subsoil below, by the force of capillary attraction. Expe- 

 rience has proved that soils gorged with water cannot 

 perfect crops ; that excess of water is a hindrance to the 

 due mechanical action of the soil ; that it diminishes or 

 checks the power of all kinds of manures ; that it lowers 

 the temperature of the mass of the soil ; that it precludes 

 the free entrance and exchange of air, without which 

 plants cannot live or their life processes go on ; that it 

 prevents the free descent of rain through the soil. These 

 amongst other truisms concerning drainage are even more 

 effective in warm than in colder climates. 



Cropping Unhealthy Soil. When gardening is attempted 

 in soil which is not sufficiently open to allow the roots to 

 penetrate freely, the orchard dies off; no pruning or dressing 

 can keep the trees alive. The systematic analyses carried 

 out in the Technical College, Sydney, show plainly how 

 the unoxidised iron in the soil has done very serious injury. 

 In hot and dry seasons the water evaporates from the 

 surface, baking yet harder the subsoil and chilling the 

 land. Oxidation is but imperfectly carried out, and, 

 despite the application of manure, vegetation languishes. 

 Draining suddenly changes all this, and brings the soil 

 into a condition to render a grateful return for the care of 

 the agriculturist. The reason for the change brought about 

 by draining becomes very evident in a warm climate, and 

 especially where iron is abundant in the soil. During 

 moderately moist seasons trees and crops may do fairly 

 well. Both develop in the soil, gathering what may be 

 available for them in it, to a depth of three feet, possibly 

 deeper under favourable conditions. Then a wet spell 

 follows. 'I he roots become surrounded by stagnating water, 

 are gorged by the unhealthy material about them. They 

 sicken and die, the first direct indication to the owner 



