The Nature and Patterns of Agricultural Drought in Europe

Transcription

1 The Nature and Patterns of Agricultural Drought in Europe Elías Fereres and Francisco J. Villalobos Institute for Sustainable Agriculture (CSIC) & University of Cordoba, Spain

2 OUTLINE 1. INTRODUCTION: HOW RELEVANT IS DROUGHT FOR EUROPE? 2. SHOULD WE EXPECT AN INCREASE IN DROUGHT FREQUENCY/INTENSITY? 3. IMPACT OF DROUGHTS UNDER INTENSIFICATION 4. FACING DROUGHT IN AGRONOMY: A MODELING ANALYSIS 5. SOME THOUGHTS ABOUT FUTURE OPPORTUNITIES

3 HOW IMPORTANT IS DROUGHT IN EUROPE? IS IT INCREASING IN DURATION AND SEVERITY? Up to 30% of the area is affected in some years, 17% of the population is affected on the average, losses of at least 100 billion over the last 30 years Drought severity and duration in Europe (Spinoni et al., 2015)

4 Conclusions: drought has increased in Southern Europe, less so for Central Europe, and drought is decreasing in Northern and Eastern Europe.

5 WHAT ABOUT LOOKING FURTHER BACK? Wet and dry summers in Europe since 1750: evidence of increasing drought (Briffa et al., 2009)

6 Little change in global drought over the past 60 years (Sheffield et al., 2012) Depends on methodologies ET (Th.) ET (PM)

7 EUROPEAN DROUGHT OBSERVATORY We are now good at monitoring and at short term predictions

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9 Research on seasonal predictions vs. research on climate change? Agriculture could certainly use more accurate seasonal predictions

10 LOOKING AT TRENDS. Rainfall (mm) Annual Rainfall at Sacramento, CA, USA Sacramento Year

11 Annual Rainfall (mm) Annual Rainfall at Sacramento, CA, USA Sacramento y = -5,8831x R² = 0, Year

12 Rainfall (mm) Annual Rainfall at Sacramento, CA, USA Year

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14 IS THE SYSTEM MORE RESILIENT IN THE DROUGHT THAN IN THE DROUGHT OF ? NO! The expansion of permanent crops in the last 20 years HE PERILS OF UNSUSTAINABLE IRRIGATION DEVELOPMENTS IN EUROPE

15 Olive oil production (t 10 3 ) MITIGATING THE IMPACTS OF DROUGHTS An extreme example of instability in production Andalucia million ha of olive trees Year

16 The severe impact of the 2003 drought in France and Italy and even on Europe NPP (Ciasis et al., 2005)

17 THE IMPORTANCE OF EXTREME EVENTS An increase in hot spells in South East Europe Sippel and Otto, 2014

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19 Hot spells effects on wheat R.A. Fischer (1980) haying off Experiments with potted plants in a growth chamber in AU. Brief (6h), hot period (46C) on a single day at different times after anthesis (1,12,20 daa,..) RESULTS: Grain weight significantly reduced (10-20% in the absence of water stress) Also, grain number greatly affected by hot spell one day after anthesis (47% reduction).mechanisms?

20 Damage/loss of leaf area Direct impact on grain growth processes? Negative impact of N fertilization (relative grain wt. N = 82%; +N = 67%) Impact of transpiration rate on canopy temperatures (heat x water stress interactions)

21 SEEKING STRATEGIES TO COPE WITH DROUGHT

22 BIOMASS or YIELD (t/ha) A simulation of 25 years of rain fed maize in Cordoba, Spain, with AquaCrop. Features: early planting (mid February), very deep root zone (2.3 m), Two soils: moderate and high soil water holding capacity B Y Year

23 Simulation of 25 years of maize production (rain fed) at Cordoba on a very deep soil of moderate water holding capacity Relative reduction in HI Yield (t/ha)

24 Relative reduction in HI (%) MAIZE ON A VERY DEEP SOIL OF HIGH WATER HOLDING CAPACITY In most years, Biomass reduction is more important than HI reduction Yield (t/ha)

25 Relative reduction in HI (%) SIMULATION OF RAIN FED WHEAT AT CORDOBA, 60 cm soil depth, moderate SWHC The importance of HI reduction increases as Yield decreases Yield (t/ha)

26 REDUCTION DUE TO B or HI (kg/ha) CERES-wheat SIMULATION OF 40 YEARS OF WHEAT PRODUCTION IN CORDOBA B HI Years UNDER THE CORDOBA CONDITIONS, IT APPEARS THAT IMPACT OF DROUGHT ON BIOMASS PRODUCTION IS RELATIVELY MORE IMPORTANT THAN THE IMPACT ON HI.

27 If the target is to produce more biomass, how can we produce it under drought, when water is limited? One option is to do it during low evaporative demand periods. Looking at the future, we should take advantage of the (forthcoming) mild winters, and in colder climates, of the (extended) autumn season. Apparent paradox: breed for adaptation to cold in a warmer climate

28 AN EXAMPLE OF PRODUCING AT TIMES OF LOW EVAPORATIVE DEMAND Four-year experiment, ; three hybrids Summary Results Winter yields= 2,223 Kg/ha ( CV 20%) Spring yields= 1,550 Kg/ha (CV 13%)

29 However, when sown in winter, very slow seedling development under low temperatures ; often poor stands Winter plantings failed and were not adopted primarily because of competition with weeds and, to some extent also by diseases

30 Cumulative probability 1,0 0,9 0,8 THUS, FARMERS CONTINUED TO PLANT SUNFLOWER IN SPRING Simulation of Sunflower Yields sown in Spring at Cordoba, Spain ( ) 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0,0 Yield (t/ha) S 1.43 TE = 4.7 kg/ha/mm

31 Cumulative probability Simulation of Sunflower Yields sown in Winter at Cordoba, Spain ( ) 1,0 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0,0 Yield (t/ha) W 2.28 TE = 7.0 kg/ha/mm Note the increased stability, thus more sustainability! Same cultivar as in Spring

32 AN INNOVATION CAN NOW EFFECT CHANGE : 2011: first herbicide-tolerant sunflower hybrids MORE EFFECTIVE WEED CONTROL, THUS BETTER STANDS IN WINTER PLANTINGS

33 Based on the simulations of Sunflower Yields grown at Cordoba, winter plantings are more productive and stable than spring plantings Cumulative probability 1,0 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0,0 Yield (t/ha) 0 0,5 1 1,5 2 2,5 3 S 1.4 W

34 HAS IT BEEN ADOPTED?

35 TAKEN 2 WEEKS EARLIER DURING THE HEAT WAVE

36 SEVERAL CAUSES FOR THE SLOW ADOPTION: CURRENT SOIL MANAGEMENT PRACTICES NEED URGENT CHANGE LIMITED WINDOW FOR PLANTING IN WINTER ADAPTED, NEW CULTIVARS SLOW IN COMING RISK AVERSE ATTITUDES & CULTURE.. BUT IT IS FINALLY HAPPENING!!