10 The Profitable Culture of Vegetables. 



1 in 100 for the mains and 1 in 75 for the small drains; in 

 lighter soils the fall should be more than this. 



In stiff clays drains should not be more than 2ft. to 2ft. Gin. 

 deep and 15ft. apart. In porous soil with a good fall they may 

 be put in about 3ft. to 3ft. Gin. deep and 20ft. apart. In peaty 

 soils of good depth the pipes should be one or two sizes larger 

 than usual and may be put in from 5ft. to 6ft. deep and about 

 30ft. apart. 



The sizes of pipes commonly used are : for small drains 2in., 

 for sub-mains 3in., and for mains 4in., but where the fall is 

 slight it is advisable to use pipes a size larger all round. 



Where clean stones are plentiful and cheap these may be 

 used instead of pipes, laid in about 9in. thick, and they usually 

 work very well. 



In cutting trenches for the pipes always begin at the outfall, 

 which should be at least Gin. above the bottom of the ditch, to 

 allow for silting. Proper draining tools should be used, and 

 the bottom of the trench should be cut only just wide enough 

 to lay in the pipes easily without any sideplay. If the bottom 

 in any place should be cut too wide the pipes must be fixed in 

 position by stones, lumps of clay, or pieces of broken pipe. 



Drain pipes sometimes get blocked by the roots of trees 

 and deep-rooting plants and grasses ; it is, therefore, advisable 

 in laying them to keep as far away as possible from such 

 dangers. 



Deep Cultivation. When in addition to being freed from 

 excess water by drainage the soil is deeply-pulverized the good 

 effect is increased by more thorough aeration and a higher 

 temperature. This is, therefore, the next step in promoting 

 fertility, and indeed the full effect of putting in drain-pipes 

 cannot be secured until the soil is brought into this condition. 

 When this is done an enormously increased area is opened to 

 the ramifications of the roots, which penetrate the soil in all 

 directions, extracting food and moisture throughout the whole 

 mass. Seeds sown in such soil germinate sooner and stronger 

 and the plants grow more vigorously. Whether the season be 

 wet or dry land which is drained and deeply worked shows 

 earlier and better crops and finer fruits. 



