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20161
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Subject: Soil Science × Author: Navneet Kaur × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Simulating the yield of maize (Zea mays L.) under projected climate change scenarios in Punjab
    (Punjab Agricultural University, Ludhiana, 2016) Navneet Kaur; Sidhu, Prabhjyot Kaur
    The field experiment was conducted during kharif 2014 and 2015 at the Research farm, School of Climate Change and Agricultural Meteorology, PAU, Ludhiana to generate field data for the calibration and validation of the CERES-Maize model. Significantly higher plant height, leaf area index and dry matter accumulation were recorded by the maize cv. PMH 1 sown during 4th week of May which led to improved PAR interception as compared cv. PMH 2 and later sowing dates. During crop year 2015, due to lower temperature regimes, cv. PMH 1 sown during 4th week of May took more number of days to attain maturity as compared to cv. PMH 2, other sowing dates and crop year 2014. The superiority of the cv. PMH 1 over cv. PMH 2 was mainly due to longer crop duration by virtue of which it acquired better canopy architecture (more plant height and LAI) which was the main contributor towards better source to sink relation (more dry matter accumulation). This superiority was reflected in significantly higher yield attributing characters (cob length and girth, number and weight of grains per cob) and may be the reason for higher grain and biomass yield in cv. PMH 1 sown during 4th week of May as compared to other sowing dates and cultivar. The calibration and validation of the CERES-Maize model showed good agreement between the observed and simulated values with NRMSE value of 2.7 and 4.2 for anthesis and maturity respectively, and 19.7 and 17.6 grain yield and biomass yield respectively. The future simulated climatic data (temperature and rainfall) from the regional climate model viz. PRECIS (Providing Regional Climates for Impact Studies) for different agro-climatic regions, i.e. Zone II (Ballowal Saunkhri), Zone III (Amritsar, Jalandhar, Ludhiana and Patiala) and Zone V (Bathinda) of Punjab was corrected by deriving the correction factor using the difference method, Leander and Buishand method and modified difference method for the mid and end of 21st century under different SRES scenarios (A1B, A2 and B2 scenario). The analysis of the corrected data on the annual/seasonal/monthly basis revealed that we may experience hotter days and warm nights by the end of 21stcentury in Punjab. The study showed that the annual maximum and minimum temperature and rainfall by the end of 21st century are likely to increase by 2.2 to 4.6 °C, 3.5 to 6.0°C and 31 to 96 % respectively in agro-climatic zone II; by 3.0 to 6.4 °C, 3.1 to 6.5 °C and 12 to 87 % respectively in agro-climatic zone III and by 4.0 to 7.1 °C, 3.3 to 6.3 °C and 19 to 30 % respectively in agro-climatic zone V of Punjab state under various scenarios of climate change. The trend analysis of these parameters revealed there is positive linear increasing trend under different scenarios in the Punjab state. The simulation of CERES-Maize under projected climate scenarios showed the significantly decreasing duration and grain yield of maize crop in the state. The reduction in the maturity period and grain yield is more under the A1B and A2 scenario (high emission scenario) followed by B2 scenario (low emission scenario). In Punjab state, the years 2073, 2078, 2084, 2085, 2086, 2090, 2093, 2096 and 2097 under A1B scenario, years 2079, 2096, and 2097 under A2 scenario and year 2084 under B2 scenario may experience failure of maize crop (duration ≤ 70 days and grain yield < 500 kg/ha) by the end of 21st century. The higher temperatures under the A1B scenario may the cause behind more grain yield reduction as compared to other scenarios as the physiology of the crop is adversely affected under high temperature conditions.