Effect of climate change on Midwestern U.S. agriculture: Corn and soybeans in particular

1. Effect of climate change on Midwestern U.S. agriculture: Corn and soybeans in particular Denis Bbosa Agricultural and BiosystemsEngineering (A B E) AGRON 504 Global Change Term paper

2. Content • Introduction • Midwest climate trends • Temperature • Precipitation • Changes in growing season • Changes in snowfall and ice cover • Extreme precipitation, temperature and draught • Soybean experiment • Corn experiment • Evaluation and Conclusions

3. Introduction • U.S. agriculture plays a significant supply to the world’s agricultural products. • Beneficial to the increasing human population • Midwestern U.S. is considered to be very important in agricultural production (Corn Belt). • Climate change may have an impact on the agricultural production

4. Midwest U.S. map

5. Midwest climate trendsTemperature • Inter-annual variability in regional temperatures • Mean temperatures have increased overall since 1900 • Annual temperature increased by 0.0590C per decade for the period 1900-2010 • Increasing temperature in Midwest is in line with the global temperature increase of 0.0860C per decade for the period 1880-2012

6. Precipitation • Decline in the annual precipitation of the Midwest (late 1800s and the dust bowel years) • An increase from the 1930s up-to present from 2.5” to 5.5”. • Increase can be attributed to; • Heavy number of precipitation events • Increased number of wet days • Climate change

7. Changes in growing season • Growing season length increase in the region at different time periods • Increase of 14 days for frost free season (1899-1992) • Illinois growing season had increased by 7 days (1906 to 1997). • Growing season change attributed to climate and alterations in agronomic technologies

8. Changes in snowfall and ice cover • Ice cover has decreased due to warmer temperatures • Trend (1961 to 1990 and 1981 to 2010) • Decrease towards the south • Increase in the north • constant trend in the central

9. Extreme precipitation, temperature and draught • Generous increase in intense precipitation • High risks of floods in crop growing areas of the region • Less chances of drought in the Midwest (increasing precipitation)

10. Soybean experiment • soybean (Glycine max ‘Pioneer 93B15’)- Champaign, Illinois • Treatments • control (ambient[CO2] and ambient temperature) • eT (ambient[CO2] and +3.50C temperature) • eC (585 ppm[CO2] and ambient temperature) • eT + eC (585 ppm[CO2] and +3.50C temperature) • Two seasons (2009 and 2011)

11. Continuation- Soybean experiment • Hypothesizes being test were that ; a)soybean canopy temperature increase above ambient will result in lower biomass, photosynthesis, productivity and yields due to the warmth b) increasing carbon dioxide concentration and temperature compared to increased carbon dioxide concentration only will produce more biomass, yield, and photosynthesis.

12. Continuation- Soybean experimentMeasurements • A- Leaf net CO2 assimilation i.e. leaf size when expressed on a leaf-area basis • gs-stomatal conductance i.e. measure of the rate of CO2 entering or water vapor existing through the stomata of a leaf • Ci- sub-stomatal air space • A’-Daily photosynthetic carbon gain by the upper canopy - Calculated from A. • iWUE-water use efficiency

13. Continuation- Soybean experiment • WP- Water potential (tendency of water to move from one area to another due to osmosis, gravity, mechanical pressure, or matrix effects such as capillary action ) • OP-Osmotic potential • AGB-Above ground biomass (all living biomass above the soil including stem, stump, branches, bark, seeds and foliage.) • SY- Seed yield • HI-Harvest index (weight of the harvested product as a percentage of the total plant weight of a crop)

14. Table 1: Percentage deviations from control and between treatments. Negative numbers indicate reductions whereas positive ones show an increase in the rates of parameters. Asterisks indicate statistically significant differences of the pairwise comparisons.

15. Corn/Maize experiment • Maize (Z. mays cv 34B43) - Champaign, IL • Hypothesis • [CO2] rich atmospheres can increase photosynthesis in a rain-fed field utilizing Free Air Concentration Enrichment (FACE) technology • Experimental set-up • 4 blocks-each having 2 circles (100 m separation distance) • 1st circle-ambient [CO2] • 2ndcircle –fumigated (549 ppm)

16. Continuation- Corn/Maize experimentMeasurements • Five days were chosen • Air temperature • Relative humidity • Precipitation • A- Leaf net CO2assimilation • gs-stomatal conductance • Ci- sub-stomatal air space • A’-Daily photosynthetic carbon gain by the upper canopy

17. Table 2: Calendar date and day of year (DOY) of experimental measurements with corresponding crop growth stage described as days after emergence (DAE), ontogenetic developmental stage and height of corn under ambient (370 ppm) and elevated [CO2] (550 ppm) for the year 2002

18. Evaluation and Conclusions • CO2 and temperature –critical factors • Elevated [CO2]increase photosynthesis, growth and yield • Increase in temperature affect photosynthetic carbon uptake, seed size and yields.

19. Continuation- Evaluation and Conclusions • Soybean • High harvest index (HI): control vs. other treatments • Increased temperature lowers the HI • Corn/Maize • Leaf photosynthesis in elevated [CO2] increased significantly • other factors influencing yield should be considered.

20. Continuation- Evaluation and Conclusions • Free Air Carbon dioxide Enrichment (FACE) technology- opener to understanding crop response to elevate CO2 • Hypothesizes should be reexamined to expound on the uncertainties • Crop productivity models should incorporate variations such as; • Soil type • Fertilize applications • Topography • precipitation • crop variety • Altitude • soil conditions

21. Thank you!Any Questions?