Phd in Agricultural and Environmental Sciences
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PHD IN AGRICULTURAL AND ENVIRONMENTAL SCIENCES CYCLE XXXII Coordinator Prof. Pietramellara Giacomo CLIMATE RESILIENT CROPS IN HOT-SPOT REGIONS OF CLIMATE CHANGE THE CASE OF QUINOA IN BURKINA FASO Academic Discipline AGR 02 I declare that this PhD thesis is my own work and that, to the best of my knowledge, it contains no material previously published or written by another person, nor material which to a substantial extent has been accepted for the award of any other degree or diploma of the university or other institute of higher learning, except where due acknowledgment has been made in the text. Correspondence: Jorge Alvar-Beltrán, Department of Agronomy, Food, Environmental and Forestry Sciences and Technology (DAGRI), University of Florence, Piazzale delle Cascine 18, 50144, Florence, Italy. Email address: [email protected]; Tel.: +39-2755741 TABLE OF CONTENTS……………………………………………………………………… p.1 ABSTRACT……………………………………………………………………………………. p.5 RIASSUNTO……………………………………………………………………..…….………. p.6 ACKNOWLEDGEMENTS…………………………………………………………………… p.9 LIST OF FIGURES……………………………………………………………………………. p.11 LIST OF TABLES……………………………………………………….….…………………. p.13 LIST OF ACRONOMYS……………………………………………………………………… p.15 LIST OF ACRONOMYS: UNITS & OTHERS………………………………..……………. p.16 CHAPTER 1: GENERAL INTRODUCTION 1.1. Background information………………………………………………………….…..…….. p.17 1.1.1. Observed and projected regional changes in precipitation……………..…………… p.17 1.1.2. Observed and projected regional changes in temperature…………………..………. p.18 1.1.3. The vulnerability of Burkina Faso to climate change………………….……..……... p.19 1.1.4. Agricultural adaptation to climate change………………………….………..……… p.19 1.2. Justification of the topic and gaps in literature ………….………………………………… p.21 1.3. Research questions and problems addressed………………………………………………. p.22 1.4. Research aims and objectives………………...………………...………………………….. p.23 1.5. Structure of the research…………………………………………………………………… p.24 1.6. Contribution to the field……………………………………………………………………. p.25 CHAPTER 2: FARMER´S AWARENESS AND AGRICULTURAL ADAPTATION TO CLIMATE CHANGE IN BURKINA FASO´S DIFFERENT AGRO-CLIMATOLOGICAL ZONES (Submitted: Environmental Management Journal) 2.1. Introduction………………………………………………………………………………… p.27 2.1.1. Regional climate trends……………………………………………………………... p.28 2.2. Materials and Methods……………………………………………………………………... p.29 2.3. Results……………………………………………………………………………………… p.31 2.3.1. Climate characterization…………………………………………………………….. p.31 2.3.2. Agriculture in Burkina Faso………………………………………………………… p.34 2.3.3. Farmer’s perceptions on natural hazards……………………………………………. p.35 2.3.4. Agricultural adaptation to climate change…………………………………………... p.36 2.3.5. Vulnerability and awareness to climate change…………………………...………… p.39 2.4. Discussion…………………………………………………………………….…………...... p.41 2.5. Conclusions……………………………………………………………………………..….. p.43 1 CHAPTER 3: EFFECT OF DROUGHT AND NITROGEN FERTILISATION ON QUINOA (CHENOPODIUM QUINOA WILLD.) UNDER FIELD CONDITIONS IN BURKINA FASO (Published: Italian Journal of Agrometeorology) 3.1. Introduction…………………………………………………………………….…..……… p.45 3.2. Materials and Methods…………………………………………………….…….….……... p.46 3.3. Results…………………………………………………………………….…….…….…… p.48 3.4. Discussion...………………………………………..………………………….….….……. p.56 3.5. Conclusions…………………………………………………………………….….….…… p.57 CHAPTER 4: EFFECT OF DROUGHT, NITROGEN FERTILIZATION, TEMPERATURE AND PHOTOPERIODICITY ON QUINOA PLANT GROWTH AND DEVELOPMENT IN THE SAHEL (Published: Journal of Agronomy) 4.1. Introduction…………………………………………...…………………………………… p.59 4.2. Materials and Methods…………………………………………………………………….. p.61 4.2.1 Experimental set-up………………………………………………………………… p.61 4.2.2 Sampling and measurement………………………………………………………… p.62 4.2.3 Statistical analysis…………………………………………………………………... p.63 4.3. Results………………………………………………………………………...…………… p.63 4.4. Discussion.………………………………………………………………………………… p.72 4.5. Conclusions………………………………………………………………………………... p.75 CHAPTER 5: HEAT-STRESS EFFECT ON QUINOA (CHENOPODIUM QUINOA WILLD.) UNDER CONTROLLED CLIMATIC CONDITIONS: THE POTENTIAL OF QUINOA IN BURKINA FASO (Submitted: Journal of Agricultural Sciences) 5.1. Introduction……………………………………………………………………….……….. p.77 5.2. Materials and Methods………………………………………………………….…………. p.79 5.3. Results……………………………………………………………………………………... p.81 5.3.1. Soil analyses……………………………………………………………………...… p.81 5.3.2. Effect of HTS on yield and seed germination……………………………………… p.82 5.3.3. Spatio-temporal suitability of quinoa in Burkina Faso……..……………………… p.84 5.4. Discussion…………………………………………………………………………………. p.86 5.5. Conclusions…………………………………………………….………………………..… p.87 2 CHAPTER 6: IRRIGATION SCHEDULING OF DROUGHT-RESISTANT QUINOA IN BURKINA FASO WITH AQUACROP (Accepted: Irrigation Science Journal) 6.1. Introduction……………………………..………………………………………………… p.89 6.2. Materials and Methods………………………………………….……………………...…. p.91 6.2.1. Site description………………………………………………………………...…... p.91 6.2.2. Sampling and measurement……………………………….…………………...…... p.92 6.2.3. Soil and crop water aspects………………………………………………...……… p.92 6.2.4. AquaCrop model…………………………………………………………………... p.93 6.2.5. Statistical analysis…………………………………………………………...…….. p.93 6.3. Results…………………………………………………………………………………….. p.94 6.3.1. Field observations………………………………………………………………….. p.94 6.3.2. Calibration and validation of AquaCrop……………………………………...….… p.96 6.3.3. Simulation of eco-physiological parameters………………………………………. p.97 6.3.4. Statistical analysis of yield, biomass and canopy cover…………………………… p.99 6.4. Discussion……………………………………………………………..………...…....…... p.101 6.5. Conclusions……………………………………………………………………………….. p.102 CHAPTER 7: CAN GLOBAL WARMING HINDER THE POTENTIAL OF QUINOA IN THE SAHEL? (Submitted: European Journal of Agronomy) 7.1. Introduction………………………………………………………………………….......... p.105 7.2. Materials and Methods……………………………………………………………………. p.107 7.2.1. Crop modelling with AquaCrop and ArcGIS……………………………………… p.107 7.2.2. Generation of future climates…………………………………………………….... p.108 7.2.3. Soils grids………………………………………………………………………….. p.108 7.3. Results………………………………………………….………….……………………… p.109 7.4. Discussion……………………………………………….………….…………………….. p.116 7.5. Conclusions………………………………………………………….………………….… p.118 CHAPTER 8: GENERAL CONCLUSIONS 8.1. Past climatic trends, farmer’s awareness and agricultural adaptation……………..……… p.119 8.2. Future warming of Burkina Faso………………………………………………….……… p.120 8.3. Further research on climatic trends and agricultural adaptation…………………….……. p.120 8.4. Abiotic factors: lessons from quinoa experimentation…………………………....………. p.121 8.5. Quinoa in the Sahel: agronomic guidelines………………………………………………. p.123 8.6. SWOT (Strengths, Weaknesses, Opportunities y Threats)…………………….…………. p.124 8.7. Further research on quinoa………………………………………………………………... p.125 3 8.8. Recommendations for national and supra-national institutions……………...…………… p.126 REFERENCES.......................................................................................................................... p.127 APPENDICES Annex 1. Summary of activities…………………………………………………………… p.141 Annex 2. Technical guide for growing quinoa in Burkina Faso …..……………………… p.143 Annex 3. Results dissemination: quinoa workshop ……………………………........…….. p.145 Annex 4. Surveys on farmer’s perceptions on climate change…………………………….. p.147 Annex 5. Field evidences……………………………………………………………….….. p.149 Annex 6. Published research paper n°1………...………….…………………………….… p.159 Annex 7. Published research paper n°2……………………………………………………. p.171 4 ABSTRACT Since the industrial revolution, there has been a continuous increase in atmospheric carbon dioxide (CO2) concentrations to the highest levels in the last 800,000 years, over 400 ppm. This underscores human-induced climate change, and CO2-projections are not promising (Representative Concentration Pathway (RCP) 4.5: 550 ppm of CO2; RCP 8.5: 1000 ppm of CO2 by 2100). Scientists foresee a point of no return in the climate system, where humankind and ecosystems are expected to face unprecedented changes in climate. Populations living in less developed countries are likely to suffer the most severe impacts of climate change (heatwaves, droughts, flooding…). With uncontrollable population growth, high-reliance on climate-sensitive sectors (agriculture), lack of governance, poor educational and health systems, and conflict, a sophisticated time-bomb is developing. The time-bomb will be in the form of populations facing starvation, causing conflict and displacing, even more, the population within and from the Sahel. The Sahel is often portrayed as one of the world’s most vulnerable regions to climate change impacts, which are expected to severely affect Sub-Saharan agriculture and consequently human livelihoods. Many of the crops (maize, sorghum, millet, sugarcane, fonio and tef) grown at lower latitudes, have a C4 photosynthetic pathways which are more efficient in environments with higher solar radiation when compared to C3 crops. Nevertheless, C3 crops have a photosynthetic pathway that benefit more from increasing CO2 concentrations in the atmosphere. This is because the optimal CO2 atmospheric concentrations for enhancing the photosynthetic rate of C3 crops has not yet been reached. Modelling of C4 crops under changing climatic conditions has shown considerable yield losses of main crops (maize, millet and sorghum) within the region and for the coming decades. Trait improvement of C4 crops is time consuming with limited time for action, therefore alternative strategies to adapt to future climate are now imperative. Different