PREVENTION AND ERADICATION OF WEEDS 69 



quantities used vary considerably, the nature of the soil 

 being the determining factor in many cases. As much as 

 5, 10, or 15 tons per acre have been applied to very light 

 soils, deficient in lime, but the difference in favour of the very 

 heavy dressing is not considerable. A more general applica- 

 tion is about 30 cwts. per acre on light land, ranging up to 

 3 tons per acre where the soil is heavy and wet. Sheep's 

 sorrel will also yield to basic slag on heavy land, prob- 

 ably on account of the lime in the slag. If docks (Rumex 

 crispus and R. obtusifolius] are present in pastures they should 

 be spudded out, and if a pinch of sulphate of ammonia be 

 placed on the cut ends the roots are almost certain to be 

 destroyed. 



False brome or tor grass (Brachypodium pinnatum and 

 B. sylvaticunt) is sometimes a great pest on down pastures, 

 where its coarse growing tufts seriously depreciate the grazing 

 value of the land. Gas lime has proved an effective remedy 

 when about 2-J cwts. per perch (20 tons per acre) are applied 

 in as fresh a state as possible to the tufts of grass. 1 If spread 

 in autumn, not later than November, the false brome is soon 

 completely killed The following spring the land needs, 

 harrowing and working up to a fine tilth, when a mixture 

 of good grass seeds, suitable to the particular soil, must be 

 sown to provide a fresh turf. Gas lime is most powerful 

 when freshly made, and loses strength rapidly with exposure, 

 especially during rainy weather. 



In Cornish experiments, pasture infested with moss was 

 cleaned by suitable treatment with new superphosphate of 

 28 to 30 per cent, strength. A single application of 6 cwts. per 

 acre in February was sufficient where only a little moss was 

 present, and even when the moss was of long standing, forming 

 a dense carpet an inch thick, a second dressing was completely 

 effective. It is recommended that the superphosphate be 

 followed with a similar dressing of bone meal applied the 

 following autumn, in order to encourage the growth of herbage 

 and discourage a fresh invasion of moss. 2 At Wye, on chalky 

 soil, chemical dressings proved of little use, but mechanical 



1 Hutchinson, H. P. (1912), " Tor Grass or False Brome and its Eradication 

 from Down Pasture," Jour. Bd. Agric., XIX, pp. 648-657. 



2 " Destruction of Moss." (a) Cornwall County Council, Memoranda of 

 Results of Agric. Experiments, 1903 and 1904, pp. 32-34. (b) Cornwall 

 County Council, Notes on Agric. and Poultry Experiments, 1905 and 1906, 

 pp. iq-2o. 



