126 BIOLOGICAL PROBLEMS 



If a mixture is to form a sward rapidly, it is essential 

 that weeds should be crowded out from the beginning, 

 and that the sown species establish themselves imme- 

 diately; it is also essential, if a ley is to be uniformly 

 productive over four years, that those species which 

 are sown chiefly for the first two years do not hamper 

 the development of those which will be relied upon 

 during the last two years. Mr. Elliot appreciated 

 this when he advocated very large sowings of Cocks- 

 foot and decreased sowing of Rye-grass. The exces- 

 sive sowings of Rye-grasses in common use are largely 

 due to the fact that Rye-grass is known to contribute 

 very largely to the best old pastures on really good 

 soils; it does not follow, however, that they will do 

 so on poorer soils, or that they will persist from com- 

 mercial seed the mathematical basis of drawing up 

 a seeds mixture is hopelessly wrong in respect to 

 Rye-grasses. 



The Rye-grasses when sown to excess will, of course, 

 ensure a heavy crop of hay, and the farmer is too apt 

 to judge his ley almost entirely by his first hay crop. 

 Cocksfoot and Timothy, however, if they are not set 

 to compete with too much Rye-grass will, as my own 

 trials in Wales have shown, yield almost equally 

 good crops in the first year, and do much to ensure 

 a remunerative herbage in subsequent years. So the 

 first essential in the formation of a good ley is to 

 decrease the normal Rye-grass sowing and add to the 

 Cocksfoot and Timothy, in so far as an adequate 

 supply of bulky top grasses is concerned. The second 

 essential, which is often overlooked, is to establish 

 rapidly a good " soul " or bottom sward, and to main- 

 tain this until the ley is ploughed down; in order to 

 do this it is necessary to establish species which have 

 in the past been generally considered as only neces- 

 sary for permanent pastures. The most desirable of 



