Book of Extended summaries ISDA

International Conference on Reimagining Rainfed Agro-ecosystems: Challenges &
Opportunities during 22-24, December 2022 at ICAR-CRIDA, Hyderabad
are that they are easily available, cheap, and eco-friendly. These nitrification inhibitors can be
coated to urea by the farmers. Keeping in this view, an experiment was initiated in maize-
castor cropping to develop strategies for enhancing adaption and mitigation of climate change.
Methodology
Field experiments were conducted in maize-castor annual rotation during 2012-2017 at
Gunegal Research Farm (GRF) of the Central Research Institute for Dryland Agriculture
(CRIDA), Hyderabad, India (17◦23′N latitude, 78◦29′E longitude, altitude 540 m above mean
sea level) in the semi-arid region of Southern part of India. Average seasonal (June–January)
rainfall during the experimental season was 510 mm, which accounts for approximately 42%
of annual potential evapo-transpiration. The soil at the experimental site represents Typic
Haplustalf. The arable part of the soil consists of 71.10% sand, 6.30% silt and 22.60% clay.
The experiment was laid out in split plot design with three replications. The treatments
comprised of flat sowing, conservation furrow and tank silt application in main plots. The
conservation furrow was made between the crop rows at the time of sowing with the
implement fabricated at ICAR-CRIDA. This implement used for sowing, fertilizer application
and conservation furrow at a time. Urea treated with natural plant products to retard
nitrification of urea were taken as sub plots. The different natural nitrification inhibitors tested
were neem cake, Karanj cake, Vitex leaf powder these were compared with FYM, un coated
urea. The test crops were cultivated with all the recommended package of practices.
Recommended dose of other fertilizer (P and K) was applied uniformly in all the treatments.
Results
In this study the different in-situ moisture conservation practices and nitrification inhibitors
significantly influenced the yield and GHG emissions. It was also observed that differential
impact of these practices on yield and N 2O emissions were observed in different years due
inter annual variation of rainfall. Among the three moisture conservation treatments,
conservation furrow recorded higher maize equivalent seed yield as compared to normal
sowing and tank silt application. The yield increase ranged between 38 to 11 %. The yield
improvement in in situ moisture conservation was higher in low rainfall years. Tank silt
application recorded higher yield over normal sowing whereas tank silt application recorded
higher yield than in-situ moisture conservation only during high rainfall years.
All the natural nitrification inhibitors recorded higher maize equivalent yields as compared to
urea and 50% nitrogen through FYM + 50% N through urea. Among the natural nitrification
inhibitors Vitex coated urea recorded higher yields as compared to FYM + 50% N through
urea, Karajin cake, neem cake coated urea, and urea alone respectively.
GHG fluxes were recorded in different treatments. It was observed that CO 2 fluxes were not
influenced by in-situ moisture conservation methods. Karanj cake coated, and neem cake
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