MSc

The study entitled “Standardization of spacing and nutrient levels for
fodder rice bean
[Vigna umbellata (Thunb.)]” was conducted at College of
Agriculture, Vellayani, Kerala during Kharif 2017 to standardize the spacing and
nutrient requirement of fodder rice bean and to study its impact on growth, yield
and quality of the crop.
The experiment was laid out in
Randomised Block Design (33
confounded factorial) with three replications.The treatments consisted of three
spacings (s1 - 30 cm x 10 cm, s2 - 30 cm x 20 cm and s3 - 30 cm x 30 cm), three
levels of nitrogen (n0 - 0 kg ha-1, n1 - 20 kg ha-1 and n2 - 30 kg ha-1) and three
levels of phosphorous (p0 - 0 kg P2O5 ha-1, p1 - 20 kg P2O5 ha-1 and p2 - 40 kg P2O5
ha-1) . FYM @ 5 t ha-1 and K2O @ 30 kg ha-1 were applied uniformly to all
treatments as basal.
The treatment s1 resulted in the highest plant height at 30 DAS and leaf:
stem ratio at harvest. Application of N @ 20 kg ha-1 registered the highest plant
height and was on par with 30 kg N (n2) while leaf stem ratio was the highest at
n2. Levels of P had no significant impact on growth characters. The treatment
combination s2n2p1 produced the tallest plants (173.17 cm) at harvest and
treatments s1n0p1 and s1n2p2 recorded the highest leaf: stem ratio (0.82) but were
on par with s1n0p0, s2n0p0, s n0p2, s1n1p0, s2n0p2 and s3n0p1.
At 30 DAS, s1 produced the highest LAI (2.27) while at harvest, s2 was
found superior. The highest NAR was observed at s1 and was on par with s3.
Closer spacing (s1) enhanced the CGR at 30 DAS and harvest. Application of 30
kg N ha-1 (n2) enhanced LAI at both stages. At 30 DAS and at harvest, higher
NAR were observed at n1 and n2. At 30 DAS, n2 and p1 registered the highest
chlorophyll contents. The treatment s1 n2 p1 (30 cm x 10 cm spacing + 30 kg N ha-1
+ 20 kg P2O5 ha-1) resulted in the highest LAI, CGR and chlorophyll content at 30
DAS.
Spacing and N levels had significant impact on green fodder yield (GFY)
and dry fodder yield (DFY). The highest GFY (12.95 t ha-1) and DFY (2.59 t ha-1)
were produced at s1 (30 cm x 10 cm) and was on par with s2. The highest GFY
(13.66 t ha-1) and DFY (2.73 t ha-1) were produced at n2 (30 kg N ha-1) and was on
par with n1. The S x N x P interaction s1 n2 p1 (30 cm x 10 cm + 30 kg N ha-1 + 20
kg P2O5 ha-1) recorded highest GFY (17.29 t ha-1) and DFY (3.46 t ha-1).
The different spacing had no impact on crude protein (CP) but the lowest
crude fibre (CF) was observed at s1. Application of 30 kg N ha-1 (n2) resulted in
the highest CP content and the lowest CF content was estimated at 0 kg N ha-1.
Among P levels, p2 recorded the highest CP (17.69%) and was on par with p1. The
lowest CF (16.43 %) was observed at s2n0p1 (30 cm x 20 cm spacing + 20 kg P205
ha-1) and was on par with s1n0p0, s1n0p1, s1n2p0, s2n0p0, s2n0p2, s3n0p0 and s3n0p1.
No variation in N uptake was observed due to treatments. Uptake of P
varied with N levels only and n1 and n2 recorded the highest P uptake. Spacing
and P levels influenced K uptake by the crop and the highest uptake was observed
at s1 and p2 but p2 was on par with p1. The three factor interaction s1n2p1 registered
the highest P and K uptake. However, it was on par with s1n1p2, s1n1p0, s2n1p1 and
s3n0p2 in P uptake and with s1n2p2 in K uptake.
Increasing N levels increased pH and EC of soil after the experiment. Soil
available N after the experiment was the highest at s3 (on par with s2) and n2 (on
par with n1). At wider spacing, application of N enhanced the availability of N in
the soil after the experiment. Available P in the soil varied with S x P interaction
but all treatment combinations were on par except s2p0 and s3p2. The highest soil
available K was observed at n0 among N levels and at p1 among P levels. The
interactions S x N, S x P and N x P significantly influenced available K in the soil.
Economic analysis revealed the highest net income (₹ 35762) and BC ratio
(3.22) at s1n2p1 (30 cm x 10 cm spacing + 30 kg N ha-1 + 20 kg P2O5 ha-1).
From the study, it can be concluded that fodder rice bean can be profitably
cultivated at a spacing of 30 cm x 10 cm with application of 30 kg N ha -1 in two
splits at 15 and 30 DAS and basal application of 20 kg P2O5 ha-1, 5 t ha-1 of FYM
and 30 kg K2O ha-1.