MSc

The study entitled “Performance of red gram (Cajanus cajan (L.) Millsp.)
intercropping systems in lowlands” was undertaken at College of Agriculture, Vellayani
during 2020-2022. The main objective was to evaluate different red gram based
intercropping systems in the summer fallow of double cropped lowland rice field in
terms of weed dynamics, biological efficiency and economics.
The field experiment was carried out at Integrated Farming System Research
Station (IFSRS), Karamana from January to June 2022 in Randomized Block Design
with 10 treatments and three replications. The treatments comprised of T1: red gram +
bush cowpea (1:2), T2: red gram + green gram (1:2), T3: red gram + fodder cowpea
(1:2), T4: red gram + finger millet (1:2), T5: sole crop of red gram, T6: sole crop of bush
cowpea, T7: sole crop of green gram, T8: sole crop of fodder cowpea, T9: sole crop of
finger millet and T10: fallow. Red gram (var. PRG 176) was raised as the main crop and
bush cowpea (var. PGCP-6), green gram (CO-6), fodder cowpea (var. Aiswarya) and
finger millet (var. VR 847) were raised as intercrops. Red gram was raised as per the
recommendation of Regional Agricultural Research Station, Palem, Telengana and the
intercrops as per KAU Package of Practice Recommendations (KAU, 2016).
The results indicated that intercropping in red gram had significant influence on
the growth and yield of both main crop and intercrops. Growth attributes of red gram,
viz., plant height, number of branches per plant, leaf area per plant and leaf area index
(LAI) showed significant variation with the intercropping systems. The treatment T5
resulted in taller plants at 30 and 60 Days after sowing (DAS), highest number of
branches at 60 and 90 DAS and highest leaf area and LAI at 30, 60 and 120 DAS.
Number of pods per plant (110.43), grain yield (1430 kg ha-1
), haulm yield (5639 kg ha1
), of red gram were also found to be highest in T5.
Growth and yield attributes of intercrops were significantly reduced under
intercropping systems. Sole crops of bush cowpea (T6) and green gram (T7) produced
highest leaf area, LAI, number of pods, grain yield and haulm yield compared to its
intercropping system. The highest plant height, number of branches, leaf area, LAI, L:S
ratio, green fodder yield and dry fodder yield were recorded in the treatment T8 (sole
crop of fodder cowpea). Similarly, finger millet when raised as sole crop (T9) registered
highest number of tillers m-2
, productive tillers m-2
, grain yield and stover yield.
Intercropping with red gram profoundly reduced the weed count, dry matter
production (DMP), and NPK removal by weeds. The treatment T8 (sole crop of fodder
cowpea) and T1 (red gram + bush cowpea) recorded the lowest weed count at 30 and 60
DAS, respectively. Higher DMP was recorded in T10 (fallow) and lowest in T1 (red
gram + bush cowpea). The lowest N removal by weeds was observed in T1 at 30 DAS
(1.36 kg ha-1
) and 60 DAS (5.24 kg ha-1
), respectively. The treatments T2 at 30 DAS
(0.66 kg ha-1
) and T1 at 60 DAS (2.05 kg ha-1
) resulted in the lowest P removal by
weeds. The treatment T1 recorded the lowest K removal at 30 DAS (0.94 kg ha-1
) and
60 DAS (1.55 kg ha-1
), respectively. In general, intercropping system exhibited more
weed smothering efficiency than sole cropping. Higher values were obtained for T1 at
30 DAS (40.86 %) and 60 DAS (58.93 %), respectively.
All crops were analyzed for N, P and K uptake and highest value was recorded
in sole crop of both main crop and intercrops.
Analysis of soil sample after harvest recorded that all parameters except
available P and K were not significantly influenced by different treatments. The highest
P and K content were observed in T8 (76.03 kg ha-1
) and T3 (150 kg ha-1
) respectively.
The dehydrogenase enzyme activity was recorded highest in treatment T1 (red gram +
bush cowpea) with the value of 356.37 μg TPF g-1 soil d-1
.
Analysis of competitive indices of intercropping system revealed that the land
equivalent ratio (LER), monetary advantage index (MAI) and red gram equivalent yield
(REY) were the highest in T1. The highest relative crowding coefficient (Kri) and
positive aggressivity value of red gram indicated the dominance and competitive nature
of red gram over intercrops. Treatment T1 (red gram + bush cowpea) produced highest
net income (₹ 138611 ha-1
) and the highest B:C ratio (3.13) was recorded in T2 (red
gram + green gram) intercropping system.
From the present study it can be concluded that the systems involving bush
cowpea and green gram in additive series (1:2) were more suitable for intercropping
with red gram in the summer fallow of double cropped lowland rice field. It was
identified as the best intercropping system considering the weed smothering efficiency,
red gram equivalent yield, land equivalent ratio, monetary advantage index, net income
and benefit: cost ratio.