8 TERMANENT AND TEMPORARY PASTURES. 



be rotiirnod witli interest in the course of a very few years, 

 ])rainaire alone will <xo a lon«^ way towards turning a marsh into 

 a prolitable pastiiri', and it lenders other improvements possible 

 at a trilliiiL,^ expense. The important ])()int to l)e urL^ed here is 

 thai ill future no undrained land shall he laid down to grass. 

 Otheiwise careful tiUage, costly manures, and the linest grass 

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

 time. Sooner or later the valuable n-rasses which are sown will 

 l)e 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 artilicially drained than through soil which is generally 

 saturated Avith moisture. Where stagnant water lies no rain can 

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

 The soil can neither breathe nor digest any fertiliser a})|)lied to it, 

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

 of })lant-life. 



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 oxj^gen sweetens and converts injurious 

 organic substances into wholesome food for ])lants. At the same 

 time, carbonic acid gas derived from rain and air ])erforins the 

 same operation for the mineral constituents of the soil. 



Another advantage Avhich 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 tlie 

 delightful surprise experienced when first they drank the cool 

 water from a ])orous jar while the thermometer registered over 

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



