APPENDIX Til 221 



and coltsfoot and some couch grass has been completely 

 cleaned in four years, the only cultivation given being plough- 

 ing and horse-hoeing. The land is much cleaner than that 

 farmed in the usual way, and resembles a garden in its freedom 

 from weeds. This result was not hoped for when the cropping 

 was commenced, the opinion of practical men being that the 

 land would soon be choked with weeds. The reasons for 

 this desirable result, however, become obvious when the 

 process is examined. In the first place the crops make an 

 extremely dense growth, and have an advantage over the weeds 

 in growing with greater rapidity. Through being deprived of 

 light and air the weeds are weakened, and when inverted by 

 the plough immediately the crop is off the ground and planted 

 over with large cabbage plants nearly all weeds are destroyed 

 the first year. Couch grass is the most tenacious of life and 

 the most difficult to destroy ; it can, however, be killed by 

 being persistently placed at a disadvantage compared with the 

 fodder crop. This method of killing weeds would seem to 

 have great possibilities applied to general farming practice. 

 Crop No. 6 might be employed on a large scale for cleaning 

 of foul land, and there appears to be no reason why this crop 

 should not be used instead of a bare fallow. Couch grass — 

 the worst enemy of the arable farmer — resists the smothering 

 effect to a greater degree than other perennial weeds, because 

 its roots g.-ow horizontally and fill the earth, whereas the roots 

 of other weeds assume a vertical position in the ground. To 

 sow weeds of agricultural plants into ground choked with the 

 roots of couch grass is to court certain failure, and must be 

 avoided. The roots of this grass, however, penetrate only to 

 a depth of about 5 inches, and if the land be ploughed to a 

 depth of 8 inches a seed-bed 2 inches deep and free from 

 weeds will be secured, and the crop will have the necessary 

 start. Couch grass buried deeply is usually killed. This fact 

 is clearly shown where a load of couch grass roots has been 

 left in a heap for some time— only the outside layer of roots 

 survive. The essential conditicms for smothering out weeds 

 arc : I. A close -growing crop mixture is required ; pure cereal 



