Green Revolution: An exploitation of structural diversity, which - - PowerPoint PPT Presentation

Food security is necessary for civilization. Food security, in turn, depends on cereals.

Green Revolution: An exploitation of structural diversity, which enhances the conversion of water (irrigation) and energy (fertilizer) into food.

For the 21st century we are asking the green revolution to do more, including:

Food for the additional one billion people every 15 years. Over nine billion by 2040? Feed for animals: protein for an emerging middle class. Fuel for more bio-energy.

Year

1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Decadenal percentage change

1 2 3

% increase in population % increase in cereal production

Pre-Green Revolution Carrying Capacity

Year (AD)

500 1000 1500 2000 Global Population (billions) 2 4 6 8 10 Estimate of Carrying Capacity, 1970 500 1000 1500 2000 Green Revolution Carrying Capacity End of Green Revolution, ~2005 500 1000 1500 2000 2 4 6 8 10 Post-Green Revolution Carrying Capacity Needed by 2050

Corn (bushels * 109)

2 4 6 8 10 12 (Not including ethanol)

Wheat (bushels * 109)

0.0 0.5 1.0 1.5 2.0 2.5

YEAR

1995 2000 2005 2010 2015 0.00 0.05 0.10 0.15 0.20 0.25

Rice (cwt * 109)

Atmospheric CO2

Eh?

• I. An indirect effect of rising carbon dioxide: warmer

temperatures.

Gas % Nitrogen (N2) 78.1 Oxygen (O2) 20.1 Argon (Ar) 0.93 Carbon Dioxide (CO2)

0.04 up to 0.100

Water (H2O)

0.05 to 1.00

No H2O and CO2? Surface temperature would be –18oC. With H2O and CO2? Surface temperature is 15oC.

Physical Consequences: Temperature

Beware of Averages.

H2O vs. CO2

 Less temperature increases where water

vapor is high, more precipitation.

 Greater temperature increases with latitude

• r altitude; winter vs. summer.

 Increased desertification, increased drought.  Rising sea levels from increased polar and

glacial melt.

Plants are essential to life.

Light Water Nutrients Carbon Dioxide The rapid increase in atmospheric CO2 will alter global plant biology.

• CO2 is a fundamental resource for plant

growth.

• Not all plants are beneficial to human society.
• Not all plants respond the same way to a

resource.

• Differential plant response will affect plant-to-

plant interactions, competitive outcomes.

Beer = 20-40 gallons Potato = 20-30 gallons Slice of bread = 20-30 gallons Salad= 40-900 gallons Steak= 2500-5000 gallons

75% of fresh water is used in agriculture.

Climate, Water and Food

Irrigation: The Colorado River

Other rivers that no longer flow to the sea.

Because of diminished snow and ice, river flows will diminish over time, even as rising Temperatures necessitate more water for agriculture.

Where else does agriculture get its water? Aquifers

Globally, all countries are using ground water at a faster rate than it is being replenished. This rate is expected to increase with warming.

Where does agriculture get its water? Rainfall: Too Little.

Global Rice and Water Use.

• Rice supplies the bulk of

calories for the world’s poor.

Production: Water, climate and cereals.

20 40 60 80 100 Paddy Remainder

Rice production

G.E.M.----G x E

“old” vs. “new” Wheat vs. Sorghum?

G.E.M.----E x M

Capture and Use: Increase resiliency.

E x M for rice: Water and Irrigation.

Flooding reduces weed competition, but requires large inputs of water And labor. In addition, flooding can exacerbate methane emissions. Rice can be seeded directly, then irrigated, using different techniques such as AWD.

Adoption of DSR in China Year

1990 1995 2000 2005 2010 2015

DSR Cultivation (Ha x 1000)

200 400 600 800

Jiangsu Province Zhejiang Province

CLIMATE AND FOOD SECURITY

 Water is indispensable for agriculture. Yet, it is clear that

climate change will significantly impact water availability. Such availability will impact rice production, but the long-term consequences are not clear.

 G x E x M as one opportunity.

What about Carbon Dioxide?

Can we select for CO2 responsiveness?

Relative Stimulation (E-A)/(A)

• 1.0
• 0.5

0.0 0.5 1.0 1.5

• 1.0
• 0.5

0.0 0.5 1.0 1.5

Seed Yield

* * * * * * * * * *

_ X = 0.42 _ X = 0.43

29/21oC 29/21oC * *

Vegetative Biomass

AR-1995-StgS DJ123 Geumobyeo IL 43-1-2 IR64 IR78049-25 IRGC105491 Jefferson Nipponbare Shirkati TeQing WAB56-104 AR-1995-StgS DJ123 Geumobyeo IL 43-1-2 IR64 IR78049-25 IRGC105491 Jefferson Nipponbare Shirkati TeQing WAB56-104

Wang et al. 2016, Global Change Biology, 22:2260

Air temperature (oC)

28 29 30 31 32 33 34 35 36

Percentage of filled spikelets in rice

40 50 60 70 80 90 100

Ambient CO2 Elevated CO2

CO2 H2O

CO2 and temperature and yield: Making things worse?

Matsui et al. 1997, Field Crops Research 51:213

• 1.0
• 0.5

0.0 0.5 1.0 1.5

(E-A)/A

• 1.0
• 0.5

0.0 0.5 1.0 1.5

• 1.0
• 0.5

0.0 0.5 1.0 1.5

* * * * * * * * * *

_ X = -0.06 _ X = -0.25 _ X = 0.12

29/21oC+Tfloral 34/26oC 34/26oC+Tfloral * * * * * Seed Yield with Increasing Temperature A. B. C.

Don’t weeds respond to CO2?

Wild vs. cultivated rice

Seed Yield (g m-2)

1000 2000 3000 4000 5000

300 µmol mol-1 CO2 400 µmol mol-1 CO2 500 µmol mol-1 CO2

Clearfield 161 Stuttgart-S "red" c b a

Relative yield of seed, Stuttgart:Clearfield

5 10 15 20

300 µmol mol-1 400 µmol mol-1 500 µmol mol-1

8 plants m-2 16 plants m-2 a a b c b c

Biological Consequence: As carbon dioxide increases, red or weedy rice responds more. Consequently cultivated rice yields decline.

Differential Response to a Resource.

A comparison of wild and cultivated rice lines.

2000 4000 6000 8000

Leaf area (cm2 per plant)

2000 4000 6000 8000

Cultivated rice lines Wild or red rice.

Total biomass at 55 DAS 300 ppm 400 ppm

Wild biotypes vs. cultivated rice.

Clearfield

Seed yield (g plant-1)

20 40 60 80 100 ~300 ppm CO2 ~400 ppm CO2

Stuttgart-S

Two different selection forces. What can weedy rice teach us about adaptation to climate change?

USING GENETIC DIVERSITY TO ADAPT TO

CLIMATE CHANGE

100 200 300

"4484" "Cl-161"

29/21 31/23 33/25

Seed Yield (g per plant)

100 200 300

"M204" Day/Night (oC)

29/21 31/23 33/25

* * * "Stg-S" * *

Can our “worst” weeds be our best hope for adapting to climate change? Ziska et al. 2014 Functional Plant Biology 41:236.

How are weeds adapting?

"4484"

10 20 30 40 50 60 70 Ambient CO2 Elevated CO2

29/21oC

Number of tillers

10 20 30 40 50 60 70

31/23oC

10 20 30 40

10 20 30 40 50 60 70

33/25oC "CL-161" 29/21oC

Ambient CO2 Elevated CO2

31/23oC

Days after sowing (DAS)

10 20 30 40

33/25oC "M204" 29/21oC

Ambient CO2 Elevated CO2

31/23oC

10 20 30 40

"Stg-S"

10 20 30 40 50 60 70

29/21oC

Ambient CO2 Elevated CO2 10 20 30 40 50 60 70

10 20 30 40

10 20 30 40 50 60 70

31/23oC 33/25oC 33/25oC

Tillers 600 : tillers 400 at 30 DAS

1.0 1.2 1.4 1.6 1.8

Seed Yield (E-A/A)

0.0 0.2 0.4 0.6 0.8 1.0 1.2 "4484" "CL 161" "M 204" "Stg-S"

R = 0.81

Adapting Yield to CO2 and Climate: Next Steps.

Koshihikari Koshihikari Liang You 84 Liang You 84 Takanari Takanari Wuyunjing21 Wuyunjing21 Wuyunjing23 Wuyunjing23 Yangdao 6 Yangdao 6 Yliangyou Yliangyou Yongyou Yongyou Zhonghua Zhonghua

Percent decline relative to ambient

• 25
• 20
• 15
• 10
• 5

Fe Zn

Change in vitamin content.

• 60
• 50
• 40
• 30
• 20
• 10

Percent decline relative to ambient.

• 60
• 50
• 40
• 30
• 20
• 10

Koshihikari Koshihikari Liang You 84 Liang You 84 Takanari Takanari Wuyunjing21 Wuyunjing21 Wuyunjing23 Wuyunjing23 Yangdao 6 Yangdao 6 Yliangyou Yliangyou Yongyou Yongyou Zhonghua Zhonghua Vitamin B1 Vitamin B2 Vitamin B5 Vitamin B9

Tocopherol

• 20

20 40 60 Koshihikari Liang You 84 Takanari Wuyunjing21 Wuyunjing23 Yangdao 6 Yliangyou Yongyou Zhonghua

Percent change relative to ambient.

Asian RIce

Ratio of Molecular Weight (N to Vitamin)

0.00 0.05 0.10 0.15 0.20 0.25

Percent Increase (relative to ambient CO2)

• 40
• 30
• 20
• 10

10 20 30 Tocopherol Vitamin B9 Vitamin B1 Vitamin B2 Vitamin B6 Vitamin B5 r2 = 0.82 P<0.001

Biological Consequences

• 1. The increase in CO2, of an by itself, will also significantly impact crop yields. It

cannot be assumed that such an impact is positive.

• 2. Because increasing CO2 affects transpirational cooling, higher temperatures may

result in greater canopy temperatures and increased sterility.

• 3. Weedy rice overall may provide a unique set of germplasm that could be used

to adapt cultivated rice to climate change through selection.

• 4. There is substantial evidence that CO2 per se, will significantly affect cereal quality,

including vitamin deficiencies in rice. Such impacts appear to have little intraspecific variation.

Overall.

• 1. The green revolution has ended; but agricultural demands have not.
• 2. The green revolution could be reversed because the basis for the increase,

i.e. water, consistent climate, cheap energy, etc. will be impacted by climatic change.

• 3. Do not assume that the increase in CO2 will negate any climate impacts. However,

as with any rapid increase in a resource, there could be opportunities for selection.

• 4. There are also management opportunities, that can help conserve resources, e.g.,

AWD in rice.

• 5. AND???????????