14 



on and the plant being generally robust and vigorous is 

 better able to battle against all pests. A caked and wet 

 soil soon cracks in the hot weather, like cotton soil, and 

 the tender roots are frequently snapped just at a time 

 when every available root is wanted for the support of 

 the plnnt. A. wet and retentive soil also prevents the air 

 from entering it by the body of water it contains , chemi- 

 cal decomposition is retarded or entirely checked, and as was 

 noted before, the formation of noxious combinations is favor- 

 ed. Both the organic and inorganic substances are liable to 

 be injuriously influenced ; for example most soils contain iron 

 and it is clearly ascertained that during the process of de- 

 composition this mineral in soils very rich in vegetable matter 

 and especially in faulty condition, is very apt to pass from a 

 peroxide to either a protoxide or sulplruret stage ; combina- 

 tions not only pernicious to all plants, but which are very 

 liable to remain in an unchanged form for years. The 

 Hutnate of iron is the most familiar example of this clnss of 

 combination and is generally to be seen in the form of an 

 unctuons exudation of a rusty color on the surface of badly 

 drained soils. 



Excessive irrigation without drainage is undoubtedly the 

 ran Re of the calamity which has attended our irrigational 

 operations in Bengal, where a saline deposit is formed on 

 the surface which makes the land barren. The simple cause 

 is, the soil was saturated with water having an affinity for, 

 the salts contained in the soil, draining was not Attended to 

 the sun consequently had to dry the soil alone and unassist- 

 ed by man and during the process of evaporation the water 

 brought to the surface, held in solution the salts, and passing 

 off in vapor, deposited them in a crust on the surface. Let 

 the ground be stirred with subsoil plough and let a regular 

 system of drainage go hand in hand with manuring and 

 irrigation and we shall never hear of such disastrous failures. 



