Abstract
A field experiment was conducted for three months during the
early growing season (April – July) of 2014 at the Teaching and Research farm
of the Faculty of Agriculture, University of Benin, Benin City. The objective
was to evaluate the performance of 7 herbaceous forage legumes in term of
growth and herbage yield. The seven forage legumes (Centrosema pascourum,
Lablab purpureus (ILR I4612), Lablab purpureus ((PI 1388013), Mucuna pruriens,
Pueraria phaseoloides, Stylosanthes hamata and Vigna unguiculata, were fitted
into a Randomized Complete Block Design (RCBD) as treatments and replicated
three times. The variables measured at 4, 8 and 12 weeks after sowing (WAS)
were soil cover score (SCS), leaf fresh weight (LFW), stem fresh weight (SFW) ,
leaves: stems ratio (L:S ratio) and fresh herbage yield (FHY) while HERBAGE
re-growth (RG) was evaluated at 8 and 12 weeks after sowing. The data collected
were subjected to Analysis of variance (ANOVA) and the means were separated
with Least Significant difference (LSD) method. Results reveal that all legumes
increased in growth at each interval of sampling. At 12 weeks after sowing,
Mucuna pruriens recorded the significantly tallest re-growth of 42.7 cm
following cutting at 8 weeks after sowing. This legume also furnished the
significantly (P<0.01) heaviest fresh herbage yield of 7.6 t ha-1. However
it produced the poorest leaves: stem ratio of 0.3 whereas Pueraria phaseoloides
recorded the best leaves: stem ratio of 1.4. Generally, the best three legumes
were Mucuna pruriens (7.5 t ha-1) > Lablab purpureus (ILRI 4612), (4.5 t
ha-1) > Lablab purpureus ((PI 1388013) (3.0 t ha-1). The poorest legumes
were Centrosema pascourum and Pueraria phaseoloides, which produced fresh
herbage yield of 0.3 t ha-1and 0.5 t ha-1, respectively. No forage legume was
affected by fungal disease although a mild defoliation by insect pest occurred.
The good growth and herbage yield exhibited makes these legumes favourable
materials for inclusion in the farming system of the rainforest zone of
Nigeria.
CHAPTER ONE
INTRODUCTION
Forage legumes are important in agricultural intensification
(Tarawali et al., 2001) because they provide herbage for livestock, grains for
humans, green manure to the soil, nitrogen to both companion and subsequent
crops through legume fallows. Increased usage of forage legumes in the tropics
and sub-tropics is inevitable because of limited supply and high cost of
in-organic nitrogen fertilizer including the serious protein deficiency
problems among human and animal populations (Hoveland, 1986). Forage legumes
which are synonymously referred to as cover crops are reputed to be the
backbone of sustainable annual cropping systems (Sullivan, 2012). Their use is
very relevant in the humid tropics where high rainfall rapidly depletes soil
nutrients especially nitrogen. They also replenish soil-organic matter content
while suppressing weeds. Forage legumes accumulated 144 kg ha-1 N, 18 kg ha-1 P
and 140 kg ha-1 K after 4 months of re-growth (Muhr et al., 1999).
In an effort to incorporate forge legumes into the local
cropping system of different regions, several screening trials were conducted.
Examples are in semi-arid Zimbabwe (Jingura et al., 2001), in the moist
savannah of Ghana (Barnes, 1996), in sub-humid Nigeria (Odunze et al., 2004),
in highland Cameroun (Pamo and Mubeteneh, 1995), in moist savanna of Nigeria
(Abayomi et al., 2001) and in sub-humid south-West Nigeria (Muhr et al., 1999).
Justification for the Study
Research is needed to ascertain which forage legumes are
adapted to the humid rainforest region of Nigeria. Moreover, it is apparent
that no comprehensive evaluation of forage legumes has been carried out in the
humid rainforest of Nigeria. Furthermore, it was reported that the performance
of forage legume in terms of herbage and crude protein yields is influenced by
location (Muhr et al., 1999). The use of forage legumes in the humid rainforest
of Nigeria will increase because commercial livestock production has increased
in the region. There are now more non-trypanotolerant breeds of beef cattle
such as white Fulani, Zebu (ILCA, 1990) and trypanotolerant breeds such as
Muturu and Ndama cattle in the region. These animals require protein rich
forage legume herbage to supplement their feeding.
Consequently, this research was carried out in the humid
rainforest region of Edo State, Nigeria with a specific objective,
Objective of the Study
To evaluate the performance of seven herbaceous forage
legumes in terms of growth and herbage yield.