28 THE SOIL or THE FAKM. 



plain the ])ractice, often to be seen, of allowing worn out 

 land to rest for a while after a long period of mismanage- 

 ment has exhausted its fertility. The success of this ex- 

 pedient, however, does not justify the practice, which is 

 obviously most wasteful both of time and means. The 

 amount of active fertility in the soil ought, by a judicious 

 system of cropping and consumption on the farm, to be 

 made nearly to reproduce itself year by year ; and the 

 gradual development of that which lies dormant, instead 

 of acting as a sinking fund to wipe out the evils of past 

 mismanagement would then go annually to increase the 

 fertility of the land. 



CHAPTER IV. 



IMPROVEMENT OF SOILS. — DRAINAGE AND IRRI- 

 GATION. 



Land-Drainage — objects, process, results, expense and profit.— Irrigation 

 — object aimed at, methods adopted, results. — Sewage irrigation. 



Land Drainage. — AVhatever the composition or natural 

 capability of a soil, its fertility depends materially upon 

 its relations to the water which falls upon it. If the rain- 

 water has free access throughout it, free passage through 

 it, not only are ingredients added which the roots ab- 

 sorb for the nourishment of the plant, but these in- 

 gredients are available in the laboratory of the soil for 

 those purposes by which i)lantfo()d is manufactured from 

 the material of soil itself and from the manure added to 

 it ; and, above all, the full use is obtained of a necessary 

 carrier of ])1 ant food l)y the hungry moutlis — theabsorl)e«t 

 ends of root-Iibres to whith it must be brought. Upon 



