Book of Extended summaries ISDA

International Conference on Reimagining Rainfed Agro-ecosystems: Challenges &
Opportunities during 22-24, December 2022 at ICAR-CRIDA, Hyderabad
Methodology
The field experiment was carried out during the rabi seasons of 2017-18 and 2018-19 at
B.C.K.V in sandy loam alluvial soil laid out in split-plot design with four main plot treatments
viz. I1 = Irrigation at 15 days intervals (farmers’ practice), I2 = Irrigation at IW/CPE ratio 0.6,
I 3= Irrigation at IW/CPE ratio 0.8, I 4= Irrigation at IW/CPE ratio1.0 and three subplot
treatments viz. N1=100% RDN (Recommended dose of nitrogen) @ 100 kg N ha -1 (inorganic
urea), N 2=75% RDN (inorganic urea) +25% RDN (vermicompost) and N 3= 100% RDN
(vermicompost) replicated thrice. Vermicompost containing 1.8 % N was applied @ 5.5 and
1.4 t ha -1 to supplement 100 kg and 25 kg N ha -1 in N3 and N2 treatments respectively. P2O5
and K 2O @ 60 and 50 kg ha -1 respectively were applied uniformly to all plots. Irrigations based
on IW/CPE ratio 1.0, 0.8 and 0.6 were given as per treatments when cumulative pan
evaporation (CPE) reached at 50, 62.5 and 83.3 mm respectively and 50 mm depth of irrigation
water was maintained in each irrigation. Seedlings of lettuce var. ‘Chinese Yellow’ were
transplanted with a spacing of 40 cm × 30 cm in 4.8 m × 3.6 m plots with other management
practices.
Results
Pooled results revealed that irrigation scheduled at 15 days interval along with 75% RDN from
inorganic urea and 25% RDN from vermicompost treatment (I 1N 2) performed significantly
better in terms of plant height (20.80 cm), fresh weight (681.55 g), yield (32.85 t ha -1 ) and
water use efficiency (92.38 kg ha-mm -1 ), whereas, maximum no. of leaves plant -1 (52.89) was
recorded in irrigation scheduled at 15 days interval along with 100% RDN from inorganic urea
treatment (I1N1) which was statistically at par with I1N2. However, irrigation scheduled at
IW/CPE 0.6 along with 100% RDN from inorganic urea treatment (I 2N 1) recorded lowest yield
(18.15 t ha -1 ).
Conclusion
The study concluded that irrigation scheduled at 15 days interval along with 75% RDN from
inorganic urea and 25% RDN from vermicompost can be recommended for better yield and
water use efficiency in lettuce in New alluvial zone of West Bengal.
Effects of irrigation and nitrogen sources on growth and yield of lettuce (Pooled)
Treatment
I 1 (Irrigation at
15-day
interval)
Plant height
(cm)
No. of leaves
plant -1
Fresh weight
plant -1 (g)
Irrigation Level (I)
Yield
(t ha -1 )
19.72 51.08 632.76 27.76
Water use
efficiency
(kg ha-mm -1 )
78.39
64 | Page Resilience through land and water management interventions, water management and governance