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It can provide a late season grazing and is most compatible with
maize or forage sorghum when intercropped. If harvested for
fodder purposes, it should be harvested just prior to the flowering
stage and when cut, it is essential to leave sufficient stubble at a
height of 10 cm - 15 cm to ensure optimal regrowth.
Soil conservation and health benefits
Lablab is well-known for its significant nitrogen contribution to soils
via nitrogen fixation and large amounts of nitrogen from decom-
posed leaf material. Improved soil fertility is therefore evident when
lablab is used as a cover crop or as a green manure crop in a cereal
intercropping system as a legume ley crop.
Management challenges
It is generally known that lablab’s early growth is slow and should
not be subjected to weed competition after establishment. Research
has shown that lablab roots have also been susceptible to nematode
attacks and that the plant can also be attacked by leaf eating insects.
With regards to soil medium restrictions, salinity has proven to have
an adverse effect on the growth of this legume. Since this plant has a
high affinity to high temperatures, it only really grows rapidly when
temperatures exceed 29°C with growth ceasing at temperatures be-
low 3°C.
Regarding extreme climatic conditions, lablab has a low tolerance
for frost, especially because this plant can seed late. This subse-
quently affects the quality of the plant since the pods are high in
protein and do not develop properly before being frosted off.
Animal production aspects
Lablab is suitably used as fodder for cattle, both as hay, silage or as
a green feed using a cut and carry system. When lablab is grazed, it
is mostly the leaves that get eaten and the stems are left.
Since it is a fast grower it can withstand frequent defoliation un-
der rotational grazing. If grazed leniently, during the first season, it
sometimes will act as a biennial and provide good spring and sum-
mer grazing the following season. When grazed, it is essential to pro-
vide a sufficient recovery period before being grazed again. It can
be used in pure stands or in mixtures as green grazing and foggage
(mixtures with maize or sorghum silage). It is not a good hay crop in
wet areas, due to thick stems that dry slowly.
It is extremely important not to allow hungry animals to only graze
lablab as it will surely result in the occurrence of bloating, especially
with young regrowth. It is recommended to graze a mixed grass/
lablab pasture, or to spray the material with an antibloating agent
prior to grazing.
It is also essential to prevent lablab from burning as it does not
tolerate fire. Numerous research trials indicate seasonal yields of
2 tons - 6 tons of DM/ha in sub-humid sub-tropics, depending on
the specific climatic conditions in which the crop is grown. To date,
literature has shown that protein quality differs when the leaf to
stem ratio changes and the protein content can range between
anything from 8,5% - 24%, depending on the amount of leaf mate-
rial present.
Lablab can make excellent hay if the leaf is preserved and the
stem material is dried properly. It is essential to facilitate the dry-
ing of the stem by introducing a curing process through mechanical
conditioning (crushing) of the stem material. When making silage
from lablab, it is advised to combine it with another crop such as
sorghum, as this will increase the protein content of the sorghum
mixture. Sorghum can additionally provide sufficient tannins to
counteract bloating to some extent.
Conclusion
Dolichos lablab is a crop that is often underestimated in inter-
cropped and livestock production systems. The most important fac-
tor to consider when using lablab in a livestock production system
is its management in terms of the anti-quality factor that is largely
responsible for bloating.
If managed properly, this legume can provide valuable, protein rich
dry matter for optimised livestock production. Over and above the
value lablab has in livestock production, it makes a significant contri-
bution to soil fertility as a cover crop.
If the plant biomass is not used by livestock, it can additionally have
great value as a green manure crop, especially since this plant has
a high amount of leaf drop which decays and contributes to the car-
bon and nitrogen levels of the soil even before the entire plant is
incorporated prior to the seeding of the next grain crop.
For more information, contact Dr Wayne Truter at wayne.
Prof Chris Dannhauser at
Dr Hendrik Smith at or Mr Gerrie
Trytsman at
Lablab flattened with a knife-roller at flowering stage, Ottosdal.
November 2015
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ON FARM LEVEL Conservation agriculture
CONSERVATION AGRICULTURE