ARABLE WEEDS. ASSOCIATION WITH SOILS 141 



(Notts), 

 weed. 



Possibly it is more usual as a garden than as a field 



C. Weeds Characteristic of Sand and very Light Soil 

 Deficient in Lime. 



Much of the sandy and very light land in this country in 

 its uncultivated condition is characterised by a marked defici- 

 ency in lime content, so much so that such soils are often 

 said to be "acid" or "sour". Soil conditions such as these 

 are not conducive to the healthy growth of a great variety of 

 plants, but there are a few weeds which are perfectly at home 

 and which revel in the very conditions that are untenable for 

 many others. The half dozen plants in this category are 

 seldom seen on ordinary soil, either because there is too much 

 lime present to please them or because they are so impatient 

 of competition that directly other plants are able to put up 

 a fight the " sour land " weeds give up the struggle at once. 



TABLE VI. WEEDS CHARACTERISTIC OF SAND AND VERY LIGHT SOIL, 



DEFICIENT IN LIME. 



Spurry {Spergula arvensis) (Fig. 36) is the greatest bug- 

 bear in the shape of weeds that farmers have to deal with on 

 sandy land. It is an annual plant which forms large 

 quantities of seeds, and when once fairly established it is 

 almost impossible to eradicate it. Liming does a great deal 

 to help, but the amount of lime that would be necessary to 

 eradicate the spurry would ruin the soil, as the dressing 

 would need to be so abnormally heavy that lime poisoning 

 would probably be set up. Spurry is so closely associated 

 with light sandy soils that one expects to find it there, 

 and, more than that, to find it dominant in many cases. As 



