Weeds of Sour Soils 



where these are intended to be grown it should not 

 be added. 



Soils which are sour often develop a growth of 

 moss upon them very quickly in moist weather, and 

 certain weeds grow well which are absent, or almost 

 so, from soils containing a sufficient supply of lime. 

 Among these weeds sheep-sorrel (Rumex Acetosella) 

 and spurrey {Spergula arvensis) or dodder, as it is 

 called in some places, but quite distinct from the true 

 dodder, are the commonest, and Hming the ground 

 does much to keep these weeds in check. Lack of 

 drainage is often similarly indicated by weeds, the 

 common hoise-ta,il{Equisetum arvense), called mare's- 

 taU in some places, and Coltsfoot {Tussilago Farfara) 

 being common examples of such stagnant water 

 indicators. With these again efficient drainage does 

 much to check their spread. 



Sour soil checks the growth of many plants and 

 encourages the growth of pests of various sorts, at 

 the same time laying the plants open to the attack 

 of the pests to an extent unknown on soUs in better 

 heart. The acids may render it more difficult for 

 roots to absorb the necessary water ; their presence 

 may actually poison the plants, while the presence 

 of water in the soil where air should be causes the 

 suffocation of roots, and therefore a cessation of the 

 water supply. 



This is not the place to point out how drainage 

 should be effected, but we may refer to one or two 



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