IMPROVEMENT OF GRASS LAND 177 



the artificial manures named. On heavy land basic slag 

 should be employed instead of superphosphate. 



Field Scabious (Cenlaurea Scabiosa L.), also known 

 as Hardheads, Great Knapweed, Matfellon, sometimes 

 occurs abundantly on dry calcareous pastures. It is 

 a perennial, with woody rootstock, grooved stem 2 to 3 

 feet high, and a covering of soft hairs. The leaves are 

 large, 4 to 10 inches long, deeply cut and lobed ; the 

 heads of bright purple flowers are ij inch or more in 

 diameter, rayed, and with more spreading flowers than 

 those of C. nigra. It flowers between June and Sep- 

 tember. In general this plant in pastures must be 

 combated as in the case of C. nigra. It occurs also 

 on arable land. 



Thistles (Cnicus sp.) are among the worst and 

 commonest weeds of grass land, and when they grow 

 most luxuriantly are, like many other weeds, held to 

 be a sign of good land. Thistles are common to both 

 grass and arable land, and are almost equally trouble- 

 some in either. Not only do they crowd out the 

 legitimate crop by taking up space, light, air, heat, 

 water, and plant food, so reducing the yield of valuable 

 produce, but they are a great trouble at the time of 

 hay harvest, harming the mowing machine, pricking the 

 hands of loaders, irritating horses, and in other ways 

 objectionable. In corn crops too they are an un- 

 mitigated nuisance. When corn must be bound by 

 hand they are a veritable pest ; in the binder they are 

 troublesome, as also at the time of stooking, carting, 

 stacking, and thrashing. In these cases the presence of 

 Thistles, as we know from practical experience, is a 

 bugbear to master and men alike. Loose barley, for 

 example, is not the pleasantest material to load when 

 over-dried, but when full of Thistles it becomes much 

 worse. In the returns given at p. 233, it will be 



M 



