Grasslands of the World.pdf - Disasters and Conflicts - UNEP

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Grasslands of the world
Plate 9.7
Leucaena leucocephala , a high quality productive shrub legume capable of
providing high levels of animal production.
based on Stylosanthes species and Leucaena leucocephala (Plate 9.7) and the
area sown to these species continues to increase. A number of other tropical
legumes have smaller but still successful roles e.g. Aeschynomene americana ,
Chamaecrista rotundifolia , Centrosema pascuorum and Vigna parkeri . There
is an increasing demand for ley legumes for cropping systems in the tropics
and sub-tropics. The cropping industry is situated mainly on clay soils which
previously supported grassland or brigalow . However years of continuous
cropping has depleted soil fertility and yields and grain protein content s are
falling. There is an urgent need to restore the fertility and legume-leys (e.g.
Clitoria ternatea ) can play a key role (Dalal et al., 1991).
While there have been positive changes from the use of legumes, such as
increased production and soil improvement , legumes can also have negative
impacts, such as accelerated soil acidification. There will be a continuing need for
research and development to overcome problems that arise, as well as continuing
management – using legumes is not simply a matter of selecting and sowing a
species and expecting it to survive and produce with little management.
Role of native pastures
Much of the research (and commercial) activity with pastures has concentrated
on exotic rather than native species. Although the possible value of native species
was realized along with the need for scientific study of their characteristics and
value (Davies, 1951), the widespread conclusion was
J.G. McIVOR