Rajiv Kumar Srivastava did Ph.D. from Agricultural and Food Engineering Department, IIT Kharagpur, West Bengal, India in Land and Water Resources Engineering. During PhD study, I have investigated the “Effect of Sowing Dates and Nitrogen Fertilization Level on Maize Yield under Climate Change Scenarios in Eastern India” based on field experiment and simulation approach under irrigated and rainfed seasons. This work has been carried out as a PhD research work at Indian Institute of Technology, Kharagpur-721302, West Bengal, India. Results based on field experiment and simulation modeling are published in International peer reviewed journals. 

During my PhD duration I dealt with a number of aspects of the maize yield under different climate change scenario, in particular the environmental impact on agricultural production such as effect of variation in sowing dates and nitrogen fertilization level on evapotranspiration, nitrogen transformation and transportation, leaching losses along with response of elevated CO2 concentrations. I looked at the variation in maize yield for two future time slice periods (2021-50 and 2051-80) under climate change scenarios. To adjudge the efficacy of future yield prediction, the bias correction was implemented by coding and decoding in R. Further, I also evaluated the shifting of sowing dates as an adaptation strategy to reduce the adverse effects of climate change.

In that initial study, I found that higher level of nitrogen fertilization is observed to reduce the agronomic N efficiency (AEN), N partial factor productivity (PFPN), and nitrogen use efficiency (NUE). It was also found that nitrogen fertilization level of 80 kg/ha for rainfed and 100 kg/ha for irrigated are most appropriate for the maize crop in a sub-tropical region so as to minimize the nitrate loss and maximize the loss of nitrogen fertilizer with maximum NUE, and AEN. The methodology involved determination of appropriate sowing dates, and nitrogen fertilization level, through field experiments and simulation modeling, for an irrigated and a rainfed maize cultivar grown in eastern region of India. 

Henceforth, application of simulation modeling, for investigation of the effect of sowing dates and nitrogen fertilization on evapotranspiration, water use efficiency, nitrate leaching and nitrogen use efficiency. Tying this simulation modeling, the impact of climate variability and climate change on maize crop yield using the past and future weather data and development of appropriate adaptation strategy to cope with the climate change was developed. The impact of climate change was evaluated in two folds by using CERES-Maize model by the past climate data of 30 years (1982-2012), and using future climate data (periods 2021-2050 and 2051-2080) of different Representative Concentration Pathways (RCP) 2.6, 4.5, 6.0, and 8.5 for four locations; West Medinipur, Bankura, Birbhum and Purulia districts of West Bengal, India. 

Ultimately, the thesis aims to answer the questions: 

how sowing dates and nitrogen fertilisation affect the agronomic nitrogen efficiency, nitrogen use efficiency, evapotranspiration, and water use efficiency?

In addition how nitrate leaching losses be minimised and how climate change trends in near future may affect the productivity of the crop? 

The answers to these questions have wider implications for assessment of the interactions among plants and the environment in managed ecosystems, with contrasting crops as a whole, in particular, for development of novel process-based mathematical models, use of existing ones, and collation and analysis of environmental and climatic data. My research results revealed that increase in N rate results in more concentration of NH4+-N and NO3−–N in soil under both rainfed and irrigated conditions. The concentration of NH4+-N is normally higher in case of irrigated maize than in case of rainfed maize because of less variation in soil water storage capacity and timely irrigation. Increase in maximum temperature affects the maize grain yield more than the minimum temperature increase for different CO2 levels. Elevated CO2 enhanced the grain yield more than the ambient CO2 scenario.

I have worked on a project sponsored by IMD, MoES, India entitled as “Forecasting of Agricultural Output using Space Agrometeorology and Land-Based Observations (FASAL)”. The project was aimed to issue multiple crop yield forecast for four districts of West Bengal, India using statistical methods (linear regression analysis) and crop yield simulation through DSSAT vs. 4.5, 4.6 Software for Rice, Wheat, Mustard and Potato. During the project period, I learned management with an ability to meet tight deadlines, manage competing demands and work effectively under pressure. Also, I am self-motivated, eager to learn and put new information into use, and can actively pursue success and aims to set high standards for performance.

During the Ph.D. work and as SRF in the project, I have presented my research findings to colleagues and professors. Also, I took active participation in National and International conferences via oral and poster presentations. I have also worked with government agencies i.e. India Meteorological Department (IMD), Pune, India and Mahalanobis National Crop Forecast Centre (MNFC), New Delhi, India in a team. Also, I can work efficiently in a self-managed and team-based projects while maintaining high ethical, professional demeanour and cooperative attitude.

Education

• Doctorate of Philosophy, Indian Institute of Technology, Agricultural & Food Engineering Department, Kharagpur, West Bengal, India; 2012- Presently Continuing

PhD Topic: Effect of Sowing Dates and Nitrogen Fertilization Level on Maize Yield under Climate Change

Scenarios in Eastern India

• Master of Technology, Agricultural Engineering, Sam Higginbottom Institute of Agriculture, Allahabad, Uttar Pradesh, India, 2012, Percentage: 83.4%; Specialization: Soil & Water Conservation

Dissertation: Validation of SCS Curve Number Model for Predicting Runoff and Sediment Yield of Eleven Watersheds

• Bachelor of Technology, Agricultural Engineering, Allahabad Agricultural Institute-Deemed University Allahabad, Uttar Pradesh, India, 2009

• Intermediate, U.P Board, Government City Intermediate College, Ghazipur, Uttar Pradesh, India, 2003

• High School, U.P Board, Shri Krishna Inter College Derghawana, Ghazipur, Uttar Pradesh, India, 2001