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t
his article is the 17th in a series of articles highlighting a
specific pasture crop species that can play an imperative
role in conservation agriculture (CA) based crop-pasture
rotations. Besides improving the physical, chemical, hydro-
logical and biological properties of the soil, such species,
including annual or perennial cover crops, can successfully
be used as animal feed.
Livestock production systems are in many ways dependant on
the utilisation of pasture species, in this case as a pasture ley crop,
and can therefore become an integral component of CA-based
crop-pasture rotations.
It is imperative to identify a pasture species fulfilling the require-
ments of a dual purpose crop, i.e. for livestock fodder and/or soil
restoration. This article focuses on an annual pasture crop common-
ly used in field husbandry to improve soil conditions and to provide
a good grazing for sheep.
Lupinus
spp., lupines or
lupiene
It is reported that there are approximately 120 species of lupines.
There are only three species of annual lupines which are impor-
tant for agricultural purposes. These include the yellow lupin
(
L. luteus
), the white lupin (
L. albus
), also known as the Italian
lupin and the blue lupin (
L. angustifolius
) also known as the narrow
leaf lupin.
One of the main properties of lupines is a presence of alkaloids in
the plant which determines how sweet or bitter the plant is.
Agro-ecological distribution
Lupines can either be planted in the winter rainfall and/or summer
rainfall region of the country. A very common area for production
for this species is in the coastal regions of the Western Cape and is
particularly used for sheep production.
The most common species planted in the Western Cape is mainly
L. angustifolius
and has become popular for sandy soils, while
L. albus
is better adapted to the loamier soils. These lupin species
are very well known to establish easier than other legumes.
They prefer a slightly acidic (not very acidic) and poorer soil, and
the nitrogen they produce is extremely valuable to the following
crop planted on that soil. The annual white lupin, also known as the
sweet white lupin in the summer rainfall region, requires moderate
temperatures for best growth and development.
It therefore thrives in the cool, moist areas of the Highveld regions
of Mpumalanga, Eastern Free State and the KwaZulu-Natal plateau.
Most lupines are grown for their high quality seed which is used as
a protein and energy concentrate in livestock feed rations.
Management and utilisation
In the summer rainfall regions, where cool and moist conditions
prevail, lupines can be planted as soon as the rainy season begins
in September/October and when these species are planted under
irrigation, they can be planted as early as August, and in March for
winter rainfall regions.
Since white lupin seed is big, high seeding rates (40 kg/ha to
50 kg/ha) are required regardless of row spacing. Fortunately,
lupines are less sensitive to soil preparation than most crops. Even
though lupin seed is big, it is recommended that the seed should
be planted shallow, no more than 3 cm deep.
Since lupines are leguminous plants, they have a low requirement
for nitrogen. Lupines prefer a lower soil pH and do not tolerate
free lime in the soil. These species respond extremely well to phos-
phorus (P) and potassium (K) and it is therefore important to build
the soil levels of these particular nutrients. Being a legume, it is
essential to ensure good inoculation of the seed, with the correct
Rhizobium bacteria.
Lupines are known for their high production of good quality seed
and it can be expected under optimal conditions, to yield anything
between 1,5 tons/ha to 4 tons/ha depending on prevailing condi-
tions. The sweet lupin is characterised by a high protein and oil con-
tent which is highly digestible by ruminants.
This crop is not suitable for grazing in the early growth stages,
since there is little regrowth. For the best value as a grazing it is
recommended that it be grazed at an advanced growth stage
when most of the growth has taken place. The carrying capacity of
lupines will all depend on the seed yield and presence of weeds.
WAYNE TRUTER,
University of Pretoria,
CHRIS DANNHAUSER,
Grass SA,
HENDRIK SMITH,
Grain SA and
GERRIE TRYTSMAN,
ARC-Animal Production Institute
Integrated crop and pasture-based
livestock production systems
– Part 17
AGRICULTURE
Conservat ion
Series
Augustus 2015
72
ON FARM LEVEL
Conservation agriculture