Simulating effect of climate change on growth and yield of maize under varying N-application in the sub-tropical hills of Meghalaya
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Date
2018
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College of Post Graduate Studies in Agricultural Sciences, CAU, Imphal
Abstract
A field experiment was conducted at the Research Farm of Water Management Division, ICAR Research Complex for NEH Region, Umiam, Meghalaya, during kharif season of 2017, following Randomized Block Design with six replications. The soil of the experimental site was sandy loam in texture having pH 4.6 and organic carbon 2.03%. The available N, P and K were 274.40, 12.14 and 214.70 kg ha-1, respectively. Maize Cv. RCM 76 was grown with four nitrogen levels (0, 60, 80 and 100 kg ha-1) for the study. Data generated were used for calibration and simulation of DSSAT CERES-Maize model to simulate the possible impact of climate change scenarios w.r.t future rainfall, temperature and CO₂ on growth and yield of maize under different N-levels for the Maize Cv. RCM 76. Maize Cv. RCM 76 showed significantly higher plant height and leaf area with each successive increase in nitrogen levels which in turn brought a significant increase in cob yield, stover yield as well as biological yield per hectare. Plant height and leaf area were recorded to be significantly higher at 100 kg N ha-1 over the other treatments, although other growth parameters like CGR and RGR, statistically showed no significant difference. Likewise, the grain yield, stover yield and biological yield also increased with the increase in nitrogen levels. The yield was significantly higher at 100kg N ha-1 as compared to the other nitrogen levels (0-60 kg ha-1). Validation of the CERES-Maize model with 2017 experimental data set was done and the model was run for six years (2012 to 2017), to generate simulated yield, biomass and days to physiological maturity for a comparatively longer period of recent time and comparison of them with values simulated under different projected scenarios. Highest simulated grain yield was recorded at 125% RD level (2085 kg ha-1), followed by RD (2072 kg ha-1), 75% RD (2031 kg ha-1) and control (1148 kg ha-1). In case of simulated biomass highest value was recorded at 125% RD (9262 kg ha-1) followed by 75% RD (9077 kg ha-1) and control (6123 kg ha-1). It was observed that at -1ºC and ±19% and ±50% average rainfall, grain yield increased by 3.9-18% at fertilized treatments, while at control, the grain yield reduced by 0.7% and 9.4% (at +19% and+50% of average rainfall) and increased by 13.1% and 13.4%( at -19% and -50% of average rainfall). At +1ºC and ±19% and ±50% average rainfall, grain yield reduced by 3.9-18% at fertilized treatments, while at control, the grain yield reduced by 1.4% and 4.2% (at -19% and -50% of average rainfall) and by 10.5% and 18% (at +19% and +50% average rainfall). At -2ºC and ±19% average rainfall, grain yield increased by 16.9-24.5% (at fertilized treatments) and 20.2% and 4.3% (at control). At -2ºC and ±50% average rainfall, grain yield reduced by 6.5-10.8% (at fertilized treatments) and 10.3-21% (at control). At +2ºC and ±19% average rainfall, grain yield reduced by 5.6-7.9% and at ±50% average rainfall, it reduced by 5.4-10.8 (at fertilized treatments) and 6.1% and 13.9% at ±19% and 9.3% and 21% at ± 50% (at control). At -3ºC and ±19% and -50% average rainfall, grain yield increased by 14.7-27.8% (at fertilized treatments) and 20.2% and 26.6 % ( at control). At +3ºC and ±19% and ± 50% average rainfall, grain yield reduced by 3-5.8% (at fertilized treatments) and 2.3% and 17.1 % (at control).