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Subject: Agricultural Meteorology × Author: Kothiyal, Shivani × Start date: 2020 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Optimizing productivity of maize under emission based climate scenarios by mid and end of 21st century in Punjab
    (Punjab Agricultural University, Ludhiana, 2022) Kothiyal, Shivani; Sidhu, Prabhjyot Kaur
    The study was conducted to analyse the maize yield and phenology under the future scenarios at different zones in Punjab. The CERES-Maize model was used to analyse the yield trend and observe the deviation of yield and phenological stages of two cultivars PMH1 and PMH2 during the mid-century (2021-50) and end-century (2066-95) from the baseline period (2010-2020). The CERES-Maize model was calibrated for the crop data collected under the mandatory trial of the “All India Co-ordinated Research Project on Agrometeorology” during 2018 and validated for the same trial during 2019. The calibration and validation results showed the simulated model results to be close to the observed with a low NRMSE (%) for both the cultivars PMH1 (1, 0.8, 3, 11.7) and PMH2 (0.9, 0.7, 2, 9) for anthesis, maturity, grain yield and LAI, respectively. The yield and LAI showed a polynomial relationship with the sowing window (20th May to 30th June) in Punjab with high grain yield peaks/ LAI during 20 May to 7 June as 5200-6000 kg ha-1/ 2.9-3.2 and 4200-5400 kg ha-1/ 2.8-3.0 respectively for varieties PMH1 and PMH2, respectively. The calibrated and validated model was used to study the future maize yield trend, deviation of yield and phenology from the baseline and optimization practices to avoid the negative effects. The maize yield and phenology of both the cultivars was analysed under the four scenarios RCP2.6, RCP4.5, RCP6.0 and RCP8.5 using the weather data of four GCMs (CSIRO-Mk-3-6-0, FIO-ESM, IPSL-CM5A-MR and Ensemble). The simulated maize yield trend for the current sowing dates showed a strong deviation at agroclimatic zone II (upto 94% and 77%), III (95% and 90%), IV (92% and 88%) and V (92% and 90%) for PMH1 and PMH2, respectively while the maturity for all the zones shortened by 25 days during the end-century under RCP8.5. The optimized sowing window (10th May to 14th July) was evaluated and the results showed the late dates of sowing to perform well at agroclimatic zone II and III while early sowing dates at V (Faridkot).The optimization of nitrogen doses (lower: 65kg ha-1; higher: 185 kg ha-1) showed slight yield increment at higher doses for agroclimatic zone II, III and V (Faridkot). Amongst the four GCMs, the FIO-ESM model overestimated the yield while the CSIRO-Mk-3-6-0 under estimated the yield. The optimization practices if used efficiently can help avoid climate change impact on maize crop in Punjab but only during mid-century under all the scenarios while under RCP8.5 during end-century no yield increment was observed.