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Subject: Agricultural Meteorology × End date: 2018 × Thesis Type: Ph.D ×
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    Impacts of climate change on spatio-temporal variability in cropping patterns over trans-gangatic plains
    (Punjab Agricultural University, Ludhiana, 2018) Baljeet Kaur; Som Pal Singh
    In the present study, analysis of spatial and temporal variation in climatic parameters and cropping patterns in trans-gangetic plains was carried out. The historical climatic data and data pertaining to area and productivity of wheat, rice and maize crops for the period 1971-72 to 2015-16 were employed for the investigation. The climatic data was analysed on the basis of decades, years and season using Mann Kendall and Sen’s slope statistics to examine the variability and trends over the study area. Spatial and temporal interpolations using Inverse Distance Weighted (IDW) method were used to develop the gradient of the data. Relative change in area of wheat, rice and maize was determined decade-wise. Step-wise regression was used to study the impact of climate change on wheat, rice and maize productivity. Under future climatic scenario RCP8.5, InfoCrop model was evaluated to project the wheat, rice and maize yields. During rabi season, higher rate of maximum and minimum temperature was observed for Haryana and central zone of Punjab. No trend was observed in rainfall in trans-gangetic plains. Rate of increase in maximum temperature was 0.063 oC for Haryana, 0.04 oC for northern Rajasthan and 0.049 oC for Delhi. Rate of increase in minimum temperature was 0.031oC for Punjab and 0.045 oC for Haryana. Area under wheat over TGP increased at the rate of 468 ha per decade significantly (R2 =0.92). It has increased by 24.68%, 80.93%, 9.39% and 39.80% in Punjab, Haryana, northern Rajasthan and TGP; respectively whereas area under wheat in Delhi decreased by 57.78% as compared with 1971-80. The analysis of area under rice and maize revealed that area under maize declined over the trans-gangetic plain region by 70.7% in 2016 compared with 1980. Per cent change in rice area was 157.6 in TGP. Wheat and maize productivity was affected negatively mostly by minimum temperature alone. Rice productivity showed positive relationship with increasing trends of temperature. Future projection of wheat, rice and maize showed that wheat productivity will decrease more in Punjab (R2=0.76) followed by Delhi (R2=0.72) and Haryana (R2=0.66). Decline in rice yield will be more in northern Rajasthan (R2=0.62) followed by Delhi (R2=0.58). More declines in maize will be in Haryana (R2= 0.77) under future climatic scenario.
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    Assessment and management of climatic variability impact on evapotranspiration and water productivity of Maize (Zea mays L.) in Punjab
    (Punjab Agricultural University, Ludhiana, 2018) Harleen Kaur; Kingra, P.K.
    ABSTRACT The field experiment entitled, “Assessment and management of climatic variability impact on evapotranspiration and water productivity of maize (Zea mays L.) in Punjab” was carried out at the Research Farm of the Department of Climate Change and Agricultural Meteorology, Punjab Agricultural University, Ludhiana for two consecutive kharif seasons of 2016 and 2017. The field experiment comprising of 12 treatments was carried out in split plot design with 3 replications having three dates of sowing (D1-Third week of May, D2-Second week of June and D3- First week of July) in main plots and two irrigation levels i.e. irrigation at IW: CPE of 1.00 (I1) and 0.75 (I2) and two mulch levels viz. mulch @ 5 t ha-1 (M1) and no mulch (M2) in the sub-plots. The soil of the experimental site was loamy sand in texture with normal pH and electrical conductivity and low in organic carbon. PAR interception and relative humidity was highest in D2 as compared to D1 and D3 and among irrigation and mulch treatments in I2 and M1. The canopy temperature was highest in D3 as compared to D1 and D2 and among irrigation and mulch in I1 and M2 treatments at reproductive stage of crop. Higher plant height, dry matter and LAI was observed in the crop sown during second week of June and among irrigation and mulch treatments in I2 and M1. The total water use was more in D1 (540.5 and 477.5 mm) as compared to the D2 (493.3 and 399.0 mm) and D3 (415.1 and 316.3 mm) in 2016 and 2017, respectively. Among mulch and irrigation levels, the total water use was more in non-mulched crop (M2) and under IW/CPE=1.00 (I1).The yield attributing characters under D2 were statistically at par with D1 and significantly higher than D3 and among mulch and irrigation treatments in M1 and I2. During 2016, difference in grain yield under different dates of sowing was found to be non-significant. During 2017, the grain yield under D2 (52.37 q/ha) was at par with D1 (50.86 q/ha) but was significantly higher than D3 (41.04 q/ha). During 2017, among mulch levels, the grain yield was significantly higher in mulch applied crop (50.71 q/ha) as compared to non-mulched crop (46.14 q/ha). The water, heat and radiation use efficiency of maize was also found to be higher under D2, I2 and M1, during both the years. The priestley-taylor method gave higher ETo in all three dates of sowing and was closer to open-pan evaporation except in first date of sowing during 2016, in which ETo was higher in FAO-56 (602.4 mm). The crop coefficients calculated by Papadakis method were comparatively higher as compared to that calculated by other methods. Good agreement was observed between actual and simulated yield (R2=0.77 each) and water productivity (R2= 0.43 and 0.44) during both the crop growing seasons. Simulation results showed that water productivity of maize increased with increase in CO2 concentration and decreased with increase in temperature, but this decrease could be compensated by simultaneous increase in CO2 concentration.
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    ThesisItemOpen Access
    Radiation Use Efficiency Of Brassica Cultivars Under Varying Environments And Validation Of ``Brassica`` Model
    (Punjab Agricultural University ;Ludhiana, 2004) Nigam, Rahul; Hundal, S. S.
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    ThesisItemOpen Access