CLIMATE CHANGE IMPACT ON RELATIONS AMONG EVAPOTRANSPIRATION, WATER USE EFFICIENCY AND CROP YIELDS ON DANUBIAN LOWLAND

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1 CLIMATE CHANGE IMPACT ON RELATIONS AMONG EVAPOTRANSPIRATION, WATER USE EFFICIENCY AND CROP YIELDS ON DANUBIAN LOWLAND Jozef TAKÁČ Bernard ŠIŠKA Pavol NEJEDLÍK Soil Science and Conservation Research Institute Bratislava Slovak Agricultural University Nitra Slovak Hydrometeorological Institute Bratislava International symposium "Climate change and adaptation options in Agriculture" June -3 9, Vienna, Austria

2 Introduction History of climate change research in SR 1991 National Climate Program of CSFR (NCP) Since 1993 National Climate Program of SR (NCP) Within the scientific and research projects Climate Change Scenarios Incremental scenarios GCM s outputs (GISS, CCCM, GFDL3) coupled GCM s outputs (GISS9, CCCM97) After 5 - CCCM. gives best control climate for th Century Newest version CGCM3.1

3 Overview Data, scenarios and methods Model calibration and validation Crop yields Crop yields scenarios CO effect on yields Water use efficiency Conclusions

4 Mt Material iland methods thd Region: Danubian Lowland Meteorological Station: Hurbanovo (observations since 171)

5 Climate data Reference period: Emission scenarios: SRES A and SRES B1 gradual increase of CO concentration Daily meteorological data (global radiation, temperature, precipitation) generated according to the outputs of GCM CGCM3.1 (Canadian Climate Centre) up to 1 Downscaling by Lapin et al., 6

6 Climate scenarios Annual mean temperature: 1. C April September:.7 C Mean annual precipitation total : 53 mm April September: 33 mm Climate scenarios SRES A Temp Prec Temp Prec Temp Prec Year IV-IX SRES Year B1 IV-IXIX

7 Soil and management data Soil Medium textured chernozem, 3.5 % humus in topsoil Cropping pattern crops (winter wheat, spring barley, winter rape, maize, sugar beet, potato, pea, alfalfa) infour 1-yearcroprotations rotations Management setup 1. rainfed. irrigated i 3. spring crops rainfed, summer crops irrigated, residuals incorporated Fertilisation Spring barley 6 kg N.ha -1 Winter wheat 15 kg N.ha -1 Maize 1 kg N.ha -1 Simulation model: Daisy (Hansen et al., 199)

8 Model calibration Crop parameters of spring barley, winter wheat, maize and sugar beet were calibrated Field experimental station of Research Institute of Irrigation in Most near Bratislava Experimental data from the period were used Fertilised as well as not fertilised crops Available data on harvested yield, top dry matter, crop N uptake, N in soil Figure (left): Simulated and measured top dry matter of winter wheat Figure (right): Simulated and measured maize N uptake Top dry matter [t.ha - ] not fertilised measured simulated Top dry matter [t.ha - ] fertilised N uptake [kg.ha - ] 3 1 not fertilised measured simulated 3 N uptake [kg.ha - ] 1 fertilised //5 3//5 /6/5 1//5 //5 3//5 /6/5 1//5 19// 1/6/ 17// /1/ 19// 1/6/ 17// /1/

9 [t.ha -1 ] simulated yield [ Model validation Yields from the Farm Lehnice Field experimental station of Research Institute of Irrigation in Most near Bratislava Experimental data from the stationary experiment Fertilised (6 variants) and not fertilised crops, rainfed and irrigated i Experimental data from the experiment Fertilised and/or residuals incorporated (3 variants), rainfed and irrigated Figure (left): Simulated and measured yield Figure (right): Simulated and measured inorganic N in soil (winter wheat) 1 6 spring barley [t.ha -1 ] simulated yield [ 1 6 winter wheat rainfed irrigated g.ha - ] N in [kg 1 9//99 /5/99 //99 6//99 N g.ha - ] N in [kg 1 9//99 /5/99 //99 6// experimental yield [t.ha -1 ] maize experimental yield [t.ha -1 ] sugar beet N in [kg.ha - ] N1 1 N in [kg.ha - ] 1 simulated yield [t.ha -1 ] simulated yield [t.ha -1 ] N in [kg.ha - ] 1 9//99 /5/99 //99 6//99 N N in [kg.ha - ] 1 9//99 /5/99 //99 6//99 experimental yield [t.ha -1 ] experimental yield [t.ha -1 ] 9//99 /5/99 //99 6//99 9//99 /5/99 //99 6//99 measured simulated

10 Crop yields [t.ha -1 ] yield 6 Mean yields (Slovakia): SK mean Hurbanovo simulated spring barley Cereals: maximum at about 199; SK trend Simulated trend decreasing after 199 mostly rainfed production, less fertilization, extreme events (hot at ripening) Maize: increasing Simulated yields (Hurbanovo): The same trends SK mean Hurbanovo simulated SK trend Simulated trend winter wheat 1 SK mean Hurbanovo simulated SK trend Simulated trend maize 6 yield [t.ha -1 ] y yield [t.ha -1 ]

11 Evapotranspiration p characteristics ET characteristics spring barley winter wheat maize calculated for the period from sowing to the harvest ET max =ET crop =crop water requirements ET/ET max [%] relative evapotranspiration ET/ET ET max -ET [mm] max [%] ET/ET max [%] evapotranspiration deficit spring barley winter wheat maize Coefficient of determination R : R (ET/ET max ) = from.6 (spring barley) to.7 (winter wheat) R (ET max - ET) = from.55 (spring barley) to (winter wheat) ET -ET [mm] ET -ET [mm] max max max top dry ma atter [t.ha -1 ] top dry matter [t.ha -1 ] top dry ma atter [t.ha -1 ] top dry matter [t.ha -1 ] top dry ma atter [t.ha -1 ] top dry matter [t.ha -1 ] ET/ET max [%] 1 3 ET max -ET [mm]

12 Evapotranspiration characteristics according to the scenarios 6 SRES A SRES A [mm] 3 [mm] 3 ET max ET max 1 Fit ET max Fit ET max 1 ET ET Fit ET Fit ET [mm] 3 [mm] 3 ET max ET max 1 Fit ET max ET Fit ET 1 ET Fit ET Fit ET max [mm] [mm] SRES A ET max Fit ET 1 max ET Fit ET ET max Fit ET max 1 ET Fit ET ET max and ET calculated from the sowing to the harvest Spring barley: increase of ET max, ET and ET/ET max, decrease of ET max -ET Winter wheat: increase of ET max, ET and ET/ET max, decrease of ET max -ET Maize: increase of ET max, ET and ET max -ET, decrease of ET/ET max (only SRES A); ET max decreasing due to shortening of the growing period at the end of the century

13 Crop development according to the scenarios Acceleration of the crop development Table: Shift of the harvest to the earlier date [days] Crop Period Scenario SRES A Spring barley Winter wheat Maize

14 Crop yields according to the scenarios grain yield [t.ha -1 ] a -1 ] Top dry matter [t.ha 6 spring barley SRES A Fit SRES A Fit grain yield [t.ha -1 ] [t.ha -1 ] Top dry matter [ maize SRES A Fit SRES A Fit yield [t.ha -1 ] grain Top dry matter [t.ha -1 ] winter wheat SRES A Fit Fit SRES A Spring barley: depression of the average yields in the first half of the century, increasing at the end of the century > 3 % (SRES A); ± 5 % () compared to Winter wheat depression of the average yields in the first half of the century (SRES A), increasing of grain yields at the end of the century about 5 % (SRES A) and 13 % () compared to Maize: depression of top dry matter yield at about 1 % (SRES A) and % (), depression of grain yield about 37 % (SRES A) and % () at the end of century compared to

15 Variability of grain yields spring barley 1 SRES A 6 rainfed maize SRES A rainfed grain yield [t.ha -1 ] grain yield [t.ha -1 ] 1 6 SRES A irrigated grain yield [t.ha -1 ] SRES A irrigated grain yield [t.ha -1 ] winter wheat SRES A Rainfed: higher variability of grain yields ha -1 ] rainfed Irrigation: reduce variability, stabilize yields grain yield [t. Cereals: rising ii yields ild under irrigation i SRES A irrigated Maize: depression of the yields also under irrigation gr rain yield [t.ha -1 ]

16 Harvest index Harve est index [%] 6 spring barley SRES A rainfed Harve est index [%] 6 maize SRES A rainfed Ha arvest index [%] SRES A irrigated H arvest index [%] SRES A irrigated Harvest index [% %] x [%] Harvest index 6 6 winter wheat SRES A SRES A rainfed irrigated Spring barley: average harvest index decrease about 1% (SRES A) and % () in 71 1 compared to Winter wheat: decrease about 3 % (), increase about % (SRES A) in 71 1 compared to Maize: decrease about 6 % () and 13 % (SRES A) in 71 1 compared to Irrigation: higher harvest index, relatively stable

17 CO effect on grain yields [%] Calculated as a difference between simulated yields with and without CO effect on photosynthesis Crop Period Scenario SRES A Spring barley Winter wheat Maize

18 Water use efficiency (grain) 5 spring barley 5 maize Water use efficien ncy [kg.mm -1 ] Water use efficie ency [kg.mm -1 ] SRES A Fit Fit SRES A 6 1 winter wheat SRES A Fit Fit SRES A WUE [ kg. mm yield = ET 1 ] ency [kg.mm -1 ] Water use efficie SRES A Fit Fit SRES A 6 1 Cereals: increase of WUE Maize: decrease of WUE CO effect on C3 plants 6 1

19 Conclusions ET max decreasing due to shortening of the growing period at the end of the century Acceleration of the crop development After decrease at the beginning of evaluated period slightly increase of cereal yields, continual decrease of maize yields higher variability of grain yields Prevail deacrease of harvest index CO effect on grain yields is important Increase of WUE for cereals, decrease for maize Irrigation reduce variability, stabilize yields