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III. Agronomic Performance of Tree Legumes

III. Agronomic Performance of Tree Legumes

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30



GRAEME BLAIR ET A L .



(Partridge and Ranacou, 1973), 11.5 t ha-' in Japan (Kitamura, 1986),

12.9 t ha-' in Australia (Ferraris, 1979), 14.3 t ha-' in Hawaii (Evensen,

1984), 14.2 t ha-' in Thailand (Topark-Ngarm, 1983), 8.4 t ha-' in the first

year of growth in Indonesia (Ella et al., 1989), and 15.6 t ha-' ha-' over a

2.5-year period in Indonesia (Catchpoole and Blair, 1990a).

There are very few reports of forage yields from other species. Holm

(1972) obtained 7.2 t DM ha-' year-' from Sesbania grandijlora in

Thailand. Chadhokar and Lecamwasam (1982) reported Gliricidia leaf

fresh weight yield in Sri Lanka in excess of 40 t ha-', with dry matter percentage of leaf ranging between 20% and 23%. Gutteridge and

Akkasaeng (1985) compared the growth of 15 tree species during the first 6

months after planting. Sesbania formosa and Sesbania sesban gave the

best yields, whereas Sesbania grandijlora was comparable to Leucaena

leucocephala and Calliandra calothyrsus. Evans and Rotar (1987b) also

obtained comparable fodder yields from various perennial Sesbania species, Calliandra calothyrsus, and Leucaena leucocephala, during the first

year after establishment. Little information is available on the best means

of establishment and subsequent management practices for most species

(Maasdorp and Gutteridge, 1986), although researchers with Leucaena

have addressed such topics as rhizobiology (Diatloff, 1973; Jarvis, 1981;

Bushby, 1982; Manjunath et al., 1984; Sanginga et al., 1986), response to

pH (Ahmad and Ng, 1981; Norani and Ng, 1981),effect of CaC03 (Hutton

and Andrew, 1978; Tham et al., 1977),nutrition and symptoms of nutrient

deficiency (Gonzales et al., 1980; Haag and Mitidieri, 1980),and methods

of establishment (Pound et al., 1980a,b;Pound and Santana, 1980; Falvey,

1981; Cooksley, 1981; 1982; Oakes, 1984; Olvera and Blue, 1985; Olvera

and West, 1985).

In an evaluation of 16 tree legumes conducted over a 4-year period in

South Sumatra, Indonesia, Blair et al. (1988) found that after a 2-year

establishment period, leaf yields were highest in Acacia mangium; this

declined with time such that the highest total leaf production was recorded

in Cassia siamea (Fig. 1).

For another species comparison experiment conducted in South

Sulawesi, Indonesia, Catchpoole and Blair ( 1990a) recorded leaf yields

of 18.2, 19.2, 21.8, and 6.7 t DM ha-' in C. calothyrsus, G. sepium,

L . leucocephala, and S . grandi3ora over a 14-month period from establishment. The high yield in Leucaena was recorded prior to the arrival of

psyllids in this part of Indonesia.

Forage yields per hectare are likely to be maximized if the shrub legumes

are in a mixture with an understory of herbaceous pasture species, through

increased efficiency of utilization of light and soil moisture (Gray, 1970).

In an experiment conducted in Indonesia, Catchpoole and Blair (199Oa)



31



FORAGE TREE LEGUMES IN TROPICAL ENVIRONMENTS

1800r



1600



0 Feb. '82 to Ian. '84



-



a JM.



'84 to Fcb. '85



69 Feb. '85 to Apr. '86



1400 -



e

.



1200



-



t

.

4

d

.



n



1000-



M



Y



U



Ix



800-



L



3



600



-



400



-



200 -



-



FIG. 1. Leaf production (g DM per tree) of the ten most productive species for three

growth periods at Nakau, South Sumatra.



Table I



Dry Matter Yields (t ha-') over a 14-Month Period of TreelGrass Mixtures and

Monocultures at Gowa, South Sulawesi, Indonesia"



Leaf DM

Stem DM

Total legume DM

Grass DM

Edible DM'

Total DM



Tree

monoculture



Treelgrass

mixture



Grass

monoculture



18 .74""



16.92"

9.18'

26. 10"

7.82"

24.74"

33.92"



12.00"

12.00"

12.00'



10.26"

29.00"

18.74"

29.00"

~



" From Catchpoole and Blair (]!Ma).



" Means within a row with the same letter are not significantly different ( p < .05).

Edible DM = legume leaf DM and grass DM.



32



GRAEME BLAIR ET AL.



found that undersowing leguminous trees (Leucaena, Calliandra, Glirici&a) with Panicum maximum cv. Riverdale increased the dry matter yield

of edible forage from 18.7 to 24.7 t ha-' over a 14-month period (Table I).

In another Indonesian experiment, Horne and Blair (1990) found that

although the quantity of light penetrating to 20 cm above the soil surface

was similar in mixtures of Leucaena cut to 100 cm with Setaria sphacelata

(HLSET) or Pennisetum purpureum (HLPEN) and Leucaena cut to 30 cm

with Setaria (LLSET) or Pennisetum (LLPEN), the shape of the light

profile was markedly different (Fig. 2) and the canopy within each stratum

had a very different grass-legume composition.



b



a



-8

v



&

8



210



170



Leucaena Leaf



130

90



60



60

40

20

0

Relallve Irradlance (100 I/Io)



100



80



60



1



I



1



I



I



4 0 20

0

Reletlve lrradlanae (100 1/10)

60



80



I



I



1



I



I



I



I



I



I



20



40



60



0



20



40



60



80



?!z5l

d



C



210



170

h



8



130



2M



90



.r.



4



t



100



0



210



v



Light proflle



p---o



90



50



GO



10100



80



60



20



40



Relallve lrradiance (100

I



1



I



0

1/10)



I



10100



80



60



20



40



0



Relative lrradiance (100 I/lo)

f



I



I



I



20

40

60

0

20

40

60

C Leaf D.M. (kg ha-ld-')

C Leaf D.M. (kg lia-'d-')

FIG. 2. Mean light profiles of the mixtures and downward cumulative leaf dry matter

production. (Z leaf) in the canopies of (a) HLSET, (b) LLSET, (c)HLPEN, and (d) LLPEN.

Horizontal bars indicate standard errors of relative irradiance means.

0



FORAGE TREE LEGUMES IN TROPICAL ENVIRONMENTS



33



The poor performance of low-cut Leucaena in both mixtures resulted

largely from competitive interference for light. Pennisefum,although slow

to recover from cutting, was able to produce a tall canopy that severely

shaded low-cut Leucaena for most of each growth period.

Examination of the mixture and monoculture leaf yields in the experiment of Home and Blair (1990) illustrates the “trade-off” that occurs

between the legume and the grass in mixtures. The data presented in Table

I1 compare the total leaf yields obtained from the mixtures over the 1-year

experimental period with the potential yields obtained when the same land

area was subdivided evenly between monocultures of the component

species (the 50 : 50 monoculture option).

Forage from all four monoculture options consisted of approximately

30% Leucaena leaf, a percentage widely considered to be optimal for

ruminant production (Pound and Martinez-Cairo, 1983). Although total

forage yields were higher from the low-cut Leucaena mixtures than from

their monoculture options, Leucaena leaf made up no more than 12% of

the total forage. The reason for this low percentage contribution, compared with the monoculture options, is the unexpectedly good performance of low-cut Leucaena in monoculture and its poor performance in

mixtures. There are many reports in the literature that low cutting has an

adverse effect on Leucaena leaf and stem yields and these have been

summarized by Home e f al. (1986).

Although successful incorporation of shrub legumes into an existing

herbaceous pasture might prove difficult (Shaw, 1965), herbaceous species

could be added to an established stand of shrub legumes by oversowing

(Jones et al., 1982). A mixture of shrub legumes and grass also helps to

provide an appropriate mixed diet for grazing ruminants (Jones and Bray,

1983) and would help reduce erosion on sloping land.

In an experiment of Catchpoole and Blair (1990a), the undersowing of

tree legumes with Panicum maximum did not increase the edible N yield of



Table 11

Total Leaf Dry Matter Yields (t ba-’ year-’) from the Mivtures and Potential Yields from

the 50 :50 Monoculture Option

Mixture



LLPEN

HLPEN

LLSET

HLSET



50 : 50 monoculture



Leucaena



Grass



Total



Leucaena



Grass



Total



0.8

4.2

2.2

8.2



15.2

10.7

16.3

6.2



16.0

14.9

18.5

14.4



4.2

4.3

4.2

4.3



9.3

9.3

10.4

10.4



13.5

13.6

14.6

14.7



34



GRAEME BLAIR ET AL.



the system (652 kg ha-' year-'). Where grass was grown as a monoculture, the edible N yield was only 88 kg ha-'.

Another approach is to fence off stands of shrub legumes and to control

stocking of the shrub legume pastures and larger areas of herbaceous

pasture in a rotation system, to enable optimum use of each pasture

resource (Shaw, 1968; Blunt and Jones, 1977; Anonymous, 1981; Paterson

et al., 1982; Foster and Blight, 1983). Judicious use of the shrub legume

component would enable high-quality feed to be accumulated for use

during dry periods (Jones and Bray, 1983). Another grazing system proposed for Leucaena (Wildin, 1980)is to grow the legume as tall trees and to

allow grazing of the lower branches and seedlings under the canopy by

stock. However, much research is needed to work out the best management system for animals grazing shrub legume pastures, such as size and

arrangement of paddocks, time and frequency of grazing, stocking rates,

tree spacing, and fertilizer requirements. The ultimate measure of pasture

productivity is animal production itself.



IV. TREE LEGUME LEAF AS ANIMAL FEED

Many plant species probably form a part of the diet of domestic animals

at some time, but Table 111 can be used as a guide to the number of

leguminous shrub and tree species used regularly as a source of feed. Often

trees and shrubs are only used for feed during drought, or other times when

herbaceous material is unavailable (Gray, 1970). A notable exception is

Leucaena leucocephala, which can be harvested year-round to provide

forage for penned animals in a cut-and-carry feed system (NAS, 1984).



Table 111

Nitrogen-Fixing Tree and Shrub Legumes Used for Forage"

Mimosoideae



No. spp.



Papilionoideae



No. spp.



Caesalpinoideae



No. spp.



Acacia

Paraserianthes

Desmodium

Leucaena

Pithecellobium

Pterocarpus

Prosopis



12

1



Cajanus

Chamaecytisus

Desmanthus

Gliricidia

Medicago

Pangamia

Robinia



1

I

I

I

1



Parkinsonia

Calliandra

Erythrina

Sesbania



1

1

2



I

5

1



2

4



After Brewbaker (1986).



I

1



4



FORAGE TREE LEGUMES IN TROPICAL ENVIRONMENTS



35



When animals are maintained in low-quality roughage such as rice

straw, the inclusion of high-protein tree legume leaf can have a significant

effect on animal performance.

An obstacle to the widespread acceptance of tree legumes as forage

sources has been low quality or palatability (Jones, 1979; Minson and

Wilson, 1980; D'Mello, 1982; Brewbaker, 1986). Chemical analyses and

digestibility data of leaf of Leucaena leucocephala, Gliricidia sepium,

and Sesbania grand;Jlora have been reported by Holm (l973), Adenaye

(1979), Minson and Wilson (1980), and Ekpenyong (1986). Vercoe (1989)

has presented data on 39 Australian tree and shrub species.

Palatability and acceptance by stock are generally not a problem with

Leucaena (Bray, 1984), but problems of stock acceptance of other tree

legume species have been reported (Skerman, 1977). Gliricidia has been

used as a feed supplement for sheep (Chadhokar and Kantharaju, 1980)

and dairy cattle (Chadhokar and Lecamwasam, 1982). Carew (1983)

showed that Gfiricidiaas the sole dry season diet for dwarf sheep was able

to maintain them for a continuous period of 21 weeks, despite an initial

drop in liveweight. There is a paucity of published information on the feed

quality of other species, despite their potential as sources of high-protein

feed for ruminant animals.

Most of the literature reporting liveweight gains of animals grazing shrub

legumes documents research predominantly undertaken in Queensland,

Australia, with Leucaena. Jones and Bray (1983) have summarized research in Australia on animal production from grazed Leucuena pastures.

Results from these experiments were obtained before Jones and Lowry

(1984) showed that the mimosine toxicity problem in Australian ruminants

could be overcome by infusion of rumen fluid from Indonesian ruminants.

Jones and Bray (1983) surmised that elimination of Leucaena toxicity

would result in a marked improvement in animal production. Despite the

toxicity problem, Falvey (1976) reported that a Leucaena-Cynodon dactylon pasture in the Northern Territory of Australia resulted in higher

liveweight gains than were obtained from heifers grazing Townsville

stylo-Panicum maximum pastures. Jones and Jones (1982) reported annual liveweight gains of cattle grazing Leucaena-Setaria pastures of 3 1 1

kg ha-' compared t o 200 kg ha-' from Siratro-Setariu pastures.

In Malaysia, Wong et af. (1983) reported that liveweight gains of cattle

rotationally grazing a Leucaena-Brachiaria decumbens mixture were

comparable to liveweight gains obtainable from nitrogen-fertilized pastures. In the Philippines, Moog (1983) reported that leaf production from

Leucaena-Zmperata cylindrica pastures is three times that from native

Imperata grasslands, and liveweight gains from Leucaena-Panicum maximum pastures have been of the order of 440 kg ha-'. However, nonru-



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