36 



PASTURES AND PASTURE PLANTS 



CHAP 



To prevent such figures being misleading, it must always be remembered 

 that the chemical analysis of any plant cannot be accepted as the true gauge 

 of worth, because stock have their hkes and dislikes in the matter of foods. 



Pure Cultures 



Disadvantages. — Experiment has conclusively demonstrated that Red 

 clover. Lucerne and Sainfoin, the three fodder plants usually sown pure in 

 this country, do not endure so long cultivated alone as when mixed with 

 suitable proportions of grasses and clovers ; and various grave objections are 

 justly urged against their extended pure culture. Thus, Red clover, from 

 its liability to " Clover-sickness," should be sown only at intervals of at least 

 6 years in duration, while there is always some risk from frost, especially in 

 the case of foreign seeds ; Lucerne succeeds on comparatively few soils ; and 

 Sainfoin, though invaluable in some situations, causes " Sainfoin-sickness " 

 by its too frequent recurrence, gives only a small crop at the second cutting, 

 and cannot be depended on in excessively wet seasons. 



Mixtures of Plants 



Advantages. — Not only do judicious mixtures of grasses and leguminous 

 plants suppress weeds by more completely occupying the ground, but they 

 utilise the different strata of soil more profitably and fully, as explained in 

 a subsequent paragraph, than can any species cultivated alone, and are 

 much less likely to cause partial chemical exhaustion of the land by using 

 up any one element too rapidly. Emile Wolff found that i,ooo air-dried parts 

 of the following plants contain : — 



Name of variety. 



Potash. 



Rye-grass . 

 Timothy.... 

 Red clover. 



Alsike 



Lucerne .... 

 Sainfoin . . . . 



7 '20 

 7-40 

 4-40 

 2 40 

 4 60 

 3 '40 



1-50 

 I 60 

 480 



3 'GO 

 790 

 4-40 



Magnesia. 



From which analysis it is obvious that while grasses draw more heavily on 

 silica, leguminous plants require much the greater proportions of lime. 

 Again, mixtures are much less sensitive to adverse external influences, such 

 as drought, excessive moisture, frost, fungous diseases and insect attacks, 

 since if any variety be injured, another more hardy or resistant temporarily 

 takes its place, and fills the blank which would otherwise be left. Frost is 

 less harmful, as the robust shelter more sensitive plants ; and Dodder and 

 Broom- rape, should they appear, are not nearly so injurious. Hence the 

 most abundant, certain and sustained yields are given by carefully composed 

 mixtures of grasses and leguminous plants, which also provide more whole- 

 some and grateful fodder than do pure sowings of either. Clovers and other 

 leguminous plants dry, too, much more readily and economically in con- 

 junction with grasses. 



