8 PEEMANENT AND TEMPOEAEY PASTUEES. 



be returned witli interest in the course of a very few years. 

 Drainage alone will go a long way towards turning a marst into 

 a profitable pasture, and it renders other improvements possible 

 at a trilling expense. The important point to be urged here is 

 that in future no undrained land shall be laid down to grass. 

 Otherwise careful tillage, costly manures, and the finest grass 

 seeds will certainly be wasted. The result is only a question of 

 time. Sooner or later the valuable grasses which are sown will 

 be supplanted by sedge and rush and other semi-aquatic vegeta- 

 tion, until the pasture gradually deteriorates to the worthless state 

 into which undrained land invariably falls. 



Every year more water passes through land which is natu- 

 rally or artificially drained than through soil which is generally 

 saturated with moisture. Where stagnant water lies no rain can 

 enter : it simply runs off the surface by any outlet it can find. 

 The soil can neither breathe nor digest any fertiliser applied to it, 

 and it is incapable of utihsing the sun's heat for the development 

 of plant-hfe. 



When rain falls on a well-drained field it does more than 

 merely moisten the soil and supply plants with water. It has 

 been computed that in each year by rain alone ten pounds of 

 nitrogen are deposited on every acre of land in this country. 

 Indeed, rain carries into the soil a very large amount of the 

 atmosphere, and this is one of the benefits which result from 

 good drainage. The oxygen sweetens and converts injurious 

 organic substances into wholesome food for plants. At the same 

 time, carbonic acid gas derived from rain and air performs the 

 same operation for the mineral constituents of the soil. 



Another advantage which results from draining is an in- 

 crease in the temperature of the soil. It is well understood that 

 evaporation produces cold, and the more rapid the evaporation 

 the greater the cold. Travellers in the East will recall the 

 delightful surprise experienced when first they drank the cool 

 water from a porous jar while the thermometer registered over 

 100°. Here is an illustration of the conditions which prevail on 



