On Weeding Land. 259 



order, that these injurious plants no longer materially im- 

 pede the growth of corn ( 36i ). 



Perennial Weeds. It is much more difficult to eradicate 

 perennial weeds, as several propagate both by their seeds, 

 and their roots. Under this head are comprehended, all the 

 sorts which come under the general name of couch, (triti- 

 cum repens). These are among the greatest banes that hus- 

 bandry has to contend with. They are sometimes so inter- 

 woven in the soil, when it has been negligently cultivated, 

 as to form a species of matting. Their destruction can 

 only be effected, by an early and complete summer fallow, 

 when, by repeated ploughings, with sufficient harrowings 

 between each ploughing, the roots may be worked out, and 

 brought to the surface. The scarifier or grubber, and some 

 recently invented harrows, are of peculiar service in extract- 

 ing the couch, after the land has been completely pulverized. 

 Besides collecting the roots by these instruments, it is an ex- 

 cellent practice, to gather them by hand-labour, employing 

 boys and girls to follow the plough, and to pick up every 

 root as fast as it is turned up. When collected, the roots, 

 should either be burnt, or deposited in a large heap, and 

 mixed with lime, and thus may become the basis of an ex- 

 cellent compost. 



It is proper to observe, that the destruction of root- weeds, 

 as couch, and of seedlings, as charlock, must be effected, in 

 arable land, upon different principles ; the former, by work- 

 ing them out of the soil in dry weather only ; the latter, by 

 pulverizing the soil, so as to induce the seed to germinate 

 after rain, and afterwards ploughing in the young plants. 



Among the perennial weeds affecting arable land, wild oats, 

 thistles, docks, and coltsfoot, or tussilago, require particu- 

 lar attention. 



The wild oat or oat-grass (holcus avenaceus) is a most 

 troublesome weed to a farmer, and difficult to be eradi- 

 cated. It formerly abounded so much in some districts, as 

 to constitute almost one half of the crop. A farmer cleared 

 a field of this weed by a most singular experiment. He 

 dressed and manured it thoroughly, and sowed no crop, 

 trusting to the oats. They grew up most abundantly. He 

 cut them for hay, before the seed was ripe, and the field was 

 never afterwards infested with that weed. Wild oats have 

 likewise been extirpated by irrigation ( 363 ). 



The common thistle (cnicus lanceolatusj and the field 

 thistle (cnicils arvcnsis) are extremely injurious to all crops. 

 They are for a time repressed, rather than destroyed, by a 



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