Tropical Grasslands-Forrajes Tropicales (2017) Vol. 5(2):100– 102 100
Book Review
Tropical forage legumes: Harnessing the
potential of Desmanthus and other genera
for heavy clay soils
Edited by JOHN R. LAZIER and NAZEER AHMAD.
Published by CABI Publishing, Wallingford, UK, 2016.
480 pp. Price US$ 225.00. ISBN 9781780646282.
DOI: 10.1079/9781780646282.0000
Over 200 years ago, Thomas Jefferson, principal author
any new species to be invasive, both within and outside
of the American Declaration of Independence and the
the various regions in which they may be seen to have
third President of the USA, also a philosopher and farmer,
agronomic and economic merit (Williams and Burt
wrote: “The greatest service which can be rendered any
1982)”.
country is to add an useful plant to its culture”. This book,
The book describes the process followed by Dr. Burt,
“Tropical forage legumes”, highlights the complexity of
his co-authors and others to expand the range of legumes
the process in domesticating species, and the remarkable
available for use on heavy clay soils in the tropics, using
work of one person in particular, Dr. Robert (Bob) L.
the range of soils and climates found in Belize and
Burt, in adding a useful plant to our culture.
northern Australia as examples. Commendably, they did
The book itself has a somewhat poignant background,
not feel constrained by the prevailing dogma that would
in that two of the initial authors, Dr. Burt and Professor
have limited them to a particular group of already
Nazeer Ahmad, died before the book was published.
recognized forage legume genera, including Desmodium,
Dr. Lazier, himself a scientist of note, and also a friend
Macroptilium and Stylosanthes, many of which had been
and colleague of both great professionals, persisted with
selected for acidic soils in the subtropics . The book
the submission out of friendship and the recognition
comprises a total of 19 chapters, largely written as journal
of the need to make the information available to others
papers with Abstract, Introduction, Materials and
working in this general field. Dr. Lazier writes: “Since
Methods, Results, Discussion and Conclusions.
this research was undertaken there has been a marked
The first 9 chapters by various combinations of Burt,
decline in the funding for such research, and with the
Lazier and Ahmad covered all aspects of the work, from
retirement of experienced researchers much of this
collection of wild-type legumes in the Yucatán Peninsula
information will be lost. This volume has been written
region of Belize, Guatemala and Mexico, as well as in the
in order that new scientists in this field will not be
Caribbean islands, to the very involved methodology of
repeating work which has already been done, and can
identifying appropriate genotypes for evaluation, and
build upon the results. Recommendations are provided
ultimately to the evaluation programs in Belize and
for further research.” Recurrent themes are that: many
Australia. While much of the statistical methodology
areas of legume species diversity remain uncollected;
might have limited appeal to many readers, the actual
potentially valuable genetic material is being lost
philosophy and techniques involved in the distillation
through global warming and increasing agricultural and
process, together with the range of genotypes
urban development; and there is an urgent need to
investigated, will have broader appeal. The authors make
conserve remaining material before it is lost completely.
the point: “It follows that if genetic material is to be
It was gratifying to note that the authors favored a
selected for trials, for use as ‘core collection’, or
responsible approach to plant introduction, particularly in
‘representative range’, it cannot be done solely on the
relation to weediness. “Attempts to meet this demand
basis of geographic or provenance data. A meaningful
(adapted legumes) have, in fact, been made for some time,
classification is required.” Krull and Borlaug made a
with the due regard that must be paid to the potential of
similar observation in 1970: “The major hurdle to
Tropical Grasslands-Forrajes Tropicales (ISSN: 2346-3775)
unlocking the secrets (of our genetic resource collections)
necessary to ensure seed production would not be a
has been our inability to classify the variability.” Various
constraint to release and adoption, and to address other
approaches to overcome this hurdle are proposed and
issues such as establishment, plant nutrition, nodulation
discussed.
and management. Once again, Desmanthus was identi-
The research homes in on two species groups in
fied as a source of adapted germplasm for pasture, along
particular, Stylosanthes hamata and Desmanthus spp.,
with another of the species discussed by Burt, initially
although a number of other species are put forward as
known as Stylosanthes sp. aff. scabra and subsequently as
being worthy of further evaluation. It should be remem-
S. seabrana. While traditional species such as Lablab
bered that the reported work was conducted in the 1970s
purpureus were unsurprisingly successful for short-term
and 80s, and results and discussion need to be interpreted
leys, two species, which had been rejected from earlier
in terms of the state of knowledge at that time. It is
evaluations in favor of more persistent species, found a
interesting to note that a number of species identified in
significant role in ley pastures on clay soils – Clitoria
the various studies reported have subsequently been
ternatea and Macroptilium bracteatum.
absorbed into international tropical agricultural systems,
The aim of plant evaluation is to bring new and useful
often as a direct or indirect consequence of the work. As
germplasm into our culture, whether it be for immediate
well as Stylosanthes hamata and Desmanthus spp. in
use by humans or livestock, or to inject a measure of
grazing systems, Desmodium cinereum (long known
sustainability into current management or production
incorrectly as Desmodium rensonii), which they flagged
systems. On this basis, Chapter 11 provides an interesting
as a species of interest, is widely used in legume
case study of how Dr. Chris Gardiner from the James
hedgerows in Southeast Asia for erosion control and live-
Cook University, Townsville, Queensland, capitalized on
stock feed. Calopogonium caeruleum and Centrosema
Dr. Burt’s earlier work in the northern part of the State,
plumieri, considered as having forage potential, have
by visiting the evaluation sites established in the 1980s,
been rejected in this role due to low palatability, but are
and collecting and identifying legume species, largely
successfully used as green manure cover crops under
Desmanthus, persisting in this particularly testing
plantations. The Australian experience with the shrub,
environment – heavy clay soils and low, unreliable annual
Codariocalyx gyroides, was similar to that in Belize; it is
rainfall. This means he started with genotypes that had
very palatable but brittle and fails to persist under grazing.
persisted for around 20 years under commercial
The ubiquitous creeping legume, Desmodium incanum,
management in the target environment. Drs. Burt and
has not been adopted commercially despite being
Lazier had already done the painstaking work of selecting
promoted as a grazing legume (Kaimi clover) in Hawaii
genetic material that had a good chance of performing
as early as the 1940s. The mimosoid shrub/small tree,
well in this environment. In the ensuing period, Dr.
Acacia angustissima, attracted some attention in
Gardiner and others have undertaken a range of studies to
Australia, but was found to be unpalatable and showed the
evaluate the most promising varieties, and to define
potential to become an environmental weed.
aspects of their agronomy and productivity necessary to
Chapter 10 by Dr. Kendrick Cox from the Department
proceed to commercial release through a partnership with
of Agriculture and Fisheries, Queensland, summarizes the
a private company. Accordingly, a mixture of 5
significant volume of work carried out in Queensland,
Desmanthus selections (three of D. virgatus and one each
Australia, seeking legumes to fulfil a range of roles on
of D. leptophyllus and D. bicornutus) is being made
alkaline clay soils, mostly in the subhumid and semi-arid
available to producers under the Progardes trade mark.
areas in central and southern parts of the State. Most of
This chapter highlights the value of returning to
the previous work focused on selecting grazing legumes
discontinued evaluation sites if persistence is one of the
for the acidic infertile soils of the more humid coastal
key criteria of merit in selecting useful genotypes, and
strip. The research covered in this chapter had two
conversely demonstrates the folly of expecting to select
primary purposes: (1) to identify legumes to supplement
persistent plants from short-term experiments.
the limited suite of species that could be used in pasture
In the final chapters, Dr. Lazier focuses again on the
leys to build up the level of labile soil nitrogen in
situation in Belize, a small country of only 23,000 km2,
preparation for subsequent cropping; and (2) to identify
about 1/5 the size of neighbouring Guatemala. He
legumes that could persist in pastures, particularly the
initially outlines the development of the beef industry in
large areas of buffel grass ( Cenchrus ciliaris) that were
the country, identifying constraints to its expansion, one
becoming less productive as nitrogen became increasing-
being limited forage development. He follows up the
ly bound up in the extensive fibrous root system of the
industry review with an analysis of native pastures, in
grass. Within each of these, additional research was
terms of both botanical and chemical composition, and
Tropical Grasslands-Forrajes Tropicales (ISSN: 2346-3775)
102
finally a series of experiments comparing the more
should be A. pintoi. There are other name changes and
productive native legumes with a range of exotic species.
misspellings in the book, but it is not the role of a reviewer
As in the earlier chapters, Dr. Lazier’s work provides a
to act as proof reader. These are mentioned merely to
roadmap of how researchers can approach a forage
draw the reader’s attention to the issue, in order to prevent
development program in an untested area. As with any
perpetuation of incorrectly spelled names.
roadmap, there are usually a number of ways to reach
This is not a text. It is a book that will appeal to people
one’s destination. It is now over 40 years since he
involved in the search for new species to play a role in the
commenced his work in Belize, in which time alternative
development of sustainable agricultural production
methodologies have been developed for evaluating plants,
systems. While it focuses on legumes for alkaline clay
which may have produced slightly different outcomes,
soils, potential readership should not be limited to those
partly through using different comparators, but also
interested solely in legumes or alkaline clay soils. There
through using non-destructive sampling.
are many facets to this publication – legume species, soil
A note of caution – some of the species names used in
chemistry, plant ecology, field and statistical method-
the book are those that would have been applied in the
ology, seed production and philosophy, not to mention a
1970s. Although many appear to have been brought into
brilliant bibliography. Even the multitude of tables, that
line with the currently accepted taxonomy, some have not,
some may find tedious, provide detail for others that
e.g. the common centro mentioned in the book is listed as
might not be available elsewhere. I cannot in all honesty
Centrosema pubescens but is now accepted as C. molle,
say that this is a book that should grace the shelves of
while C. pubescens is now applied to cv. Belalto; many
every student of leguminology, but it should be consider-
former Cassia spp. are now classified as Chamaecrista or
ed a must for libraries associated with agricultural R & D
Senna; Macroptilium longepedunculatum is now
agencies around the world in both the tropics and
accepted as M. gracile; the Arachis pusilla referred to was
subtropics.
actually misnamed in the Australian collection, and
should be Arachis triseminata. There are misspelt names
such as Desmodium cinerium, which should be
Bruce G. Cook
Desmodium cinereum, Stylosanthes sympodiales, which
Agricultural consultant (former Research Agronomist)
should be S. sympodialis, and Arachis pintoii, which
Westlake, Qld, Australia
(Published 31 May 2017)
© 2017
Tropical Grasslands-Forrajes Tropicales is an open-access journal published by Centro Internacional de Agricultura Tropical (CIAT). This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported license. To view a copy of this license, visit
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