SECTIONAL TRANSACTIONS.—M. 575 
season and the maximum benefit to that sward for production in future 
years. 
Both aspects are closely bound up with the botanical nature of the sward, 
and therefore any treatment that favours the best plants will improve the 
sward for future years, whilst any treatment that favours undesirable plants 
will cause a deterioration. 
Pastures generally contain a number of different species and strains of 
plants which are in continual competition with one another, and the experi- 
ments to be described have shown how the grazier by adjusting the rate of 
stocking at various times of the year does unconsciously determine which of 
the botanical constituents in his sward shall predominate. Starting with 
an uniform area of pasture it has been possible to convert one portion into 
a clover-dominant sward, whilst a corresponding portion has been converted 
into a grass-dominant sward. The grassy sward has been further divided, 
causing ryegrass to become dominant over cocksfoot in one section, whilst 
the adjoining section has cocksfoot as the dominant plant. 
Mr. W. Davies.—The biotic factor : lessons from Australian and 
New Zealand grasslands (11.0). 
Grassland is an unstable vegetation complex, often a direct biotic complex 
which depends upon the action of grazing animals for its maintenance as 
grassland. ‘The problems of pastures established by man in place of forest 
are compared with those of semi-arid (steppe and savannah) regions. ‘The 
influence upon the pasture complex of contrasting management and different 
types of stock are examined, as for example, the control of grazing by 
domestic live stock and uncontrolled grazing by wild animals, as rabbits, 
kangaroo and other organisms. 
The principles of pasture maintenance and pasture improvement are 
briefly considered from the several view points of (1) species and strains ; 
(2) soil fertility ; and (3) management. 
(1) Desirable attributes in herbage plants ; the value of knowing source 
of origin in purchasing pasture seeds ; seed certification in relation 
‘to herbage plants—tendencies in New Zealand, Australia and 
Britain. 
(2) The improvement of soil fertility. The value of pasture legumes as 
soil improvers and as payable pre-crops: lessons based on 
Australian experience. Pasture plants classified according to the 
demands made by them upon soil fertility. 
(3) Grazing technique in relationship to botanical composition. The 
influence upon the sward of differential grazing: (a) heavy con- 
tinuous; (b) heavy intermittent; (c) overstocking and under- 
stocking ; (d) haphazard and controlled grazing. The reactions of 
individual species and causes of depletion in semi-arid grazings. 
Mr. A. BripGes.—Some economic aspects of grassland (11.30). 
Since the war the problem of grassland has received considerably more 
attention than formerly. . In rather less than twelve years a vast amount of 
scientific knowledge has been gained in relation to the management of grass 
and placed at the disposal of farmers if they have the wish and the need to 
use it. The reason which has prompted this attack on the grassland 
question is the large increase in the area under grass since the war. A 
peculiar feature of the post-war situation is the large increase in the area 
of rough grazings. The increase in the area of grass is the result of two 
