Agroecological Strategies for Raising Crop Productivity with Reduced Inputs, with Less Water Requirement, and with Buffering of Climate-Change Stresses

Norman Uphoff, Cornell University, USA

ECHO 20th Annual Agricultural Conference

Ft. Myers, FL - December 10, 2013

In the 21st century, we will need to learn how to

PRODUCE MORE FROM LESS

This paradoxical relationship will be needed for sustainable agricultural development

Amount of arable LAND per capita is declining, with less and less reliable supplies of WATER,

and higher ENERGY costs and prices of INPUTS

We need to protect and maintain the quality of our NATURAL RESOURCES -- soil, water, air -- and to ensure broad access to APPROPRIATE TECHNOLOGIES to reduce hunger & poverty

Green Revolution technologies from 1960s contributed to meeting food needs in past

century – but they are becoming less relevant to the emerging conditions of the 21st century

What was the central thrust of GR technology? • Development and use of NEW VARIETIES, • Application of more EXTERNAL INPUTS, • Provision of more/reliable WATER, plus

• Agrochemical CROP PROTECTION

How many know the book by Francis Chaboussou, Healthy Crops: A New Agricultural Revolution (1985 in

French, English translation 2004)? Presents his theory of ‘trophobiosis’ - formulated by an INRA ag scientist

Green Revolution strategy has come to be seen as the necessary, indeed the best or the only way to achieve higher crop yields and more productivity

However, this seeds + fertilizer (+ water) strategy has been encountering diminishing returns

Diminishing returns to agrochemical inputs are being experienced clearly in China

At the start of China’s Green Revolution, farmers’ agronomic N-use efficiency was 15-20 kg rice/kg N

• By 1981-83, this had fallen to 9.1 kg rice/kg N (Lin, 1991)

• By 2001, it was 6.4 kg rice/kg N in Zhejiang province (Wang et al., 2001)

• By 2006, this ratio was 5-10 kg rice/kg N (Peng et al., 2006) – and it is still declining

S.B. Peng et al., “Improving N fertilization in rice… “

Agronomy for Sustainable Development, 30 (2010), 649-656.

At the same time, nitrate (NO3) levels in China’s groundwater supplies have been

rising rapidly, from overuse of N fertilizer

Already 10 years ago, in many parts of China, level of NO3 in groundwater was >300 ppm

-- in the US, the EPA allows only 50 ppm J.L. Hatfield, “Nitrogen over-use, under-use and efficiency.”

Paper presented to 4th International Crop Science Congress, Brisbane, Australia, September, 2004

This kind of agricultural practice has unacceptable consequences and a bleak future

Fortunately, there are alternatives to this genocentric, input-dependent strategy,

ones that are very productive and economic:

AGROECOLOGICAL METHODOLOGIES

These methodologies (methods, practices)

mobilize and utilize the biological potentials

and ecological processes and dynamics that

already exist within crop plants and that are

inherent in the soil systems within which

plants grow

Agroecological methods promote the growth of more productive PHENOTYPES

from any given GENOTYPE, i.e., variety -- does everyone know the difference?

HOW? by managing agroecosystems more productively -- rather than by focusing on

and mostly relying on external inputs HOW CAN THIS BE DONE? By improving

crops’ growing environments -- both below and above ground – this focuses on the

E factor in geneticists’ symbolic equation:

P = ƒ G + E + GxE

Agroecological practices modify and optimize the management of

plants, soil, water and nutrients, in ways that mobilize the services of the

PLANT-SOIL MICROBIOME, i.e., the multitude of beneficial microorganisms

that live in, on and around plants

Much as beneficial microorganisms

live in, on and around our human bodies, in what is called the human microbiome

Agroecological approaches include:

• Agroforestry

• Conservation agriculture (CA)

• Holistic land and livestock management (Allan Savory)

• Integrated pest management (IPM)

• Integrated crop-fish culture

• System of Rice Intensification (SRI)

• System of Crop Intensification (SCI)

Today we focus on the latter: SRI and SCI

SRI by changing management of the plants, soil, water and nutrients for growing rice: A. Induces plants to have larger, healthier

and better functioning ROOT SYSTEMS, B. Nurtures soil systems that have larger

populations of SOIL ORGANISMS which are more biodiverse and more active

Both roots & soil biota make crucial contributions to crop production, and they can reduce the current demand for both water and nitrogen fertilizer

Evidence on water saving and productivity: A meta-analysis of 29 published studies (2006-2013), with results from 251 comparison trials across 8 countries

Water use: SRI mgmt 12.03 million liters ha-1

Standard 15.33 million liters ha-1

SRI reduction in total water use = 22% SRI reduction in irrigation water use = 35% with 11% more yield (SRI 5.9 tons ha-1 vs. 5.1 tons ha-1 - usually SRI yield increase is much greater than this)

Total WUE 0.6 vs. 0.39 grams/liter (52% more) Irrigation WUE 1.23 vs. 0.69 grams/liter (78%more)

P. Jagannath, H. Pullabhotla and N. Uphoff, “Evaluation of water use, water saving and water use efficiency in irrigated rice production with

SRI vs. traditional management,” Taiwan Water Conservancy (2013)

Some demonstrations of how more productive phenotypes

are being obtained from available crop genotypes –

without reliance on new varieties,

or on chemical fertilizer, and with less water requirement,

because of better root systems and enhanced life in the soil

NEPAL: Farmer with a rice plant

grown from a single seed

with SRI methods

in Morang district

CUBA: Farmer with two plants of the same variety (VN 2084) and same age (52 DAS)

Indonesia: Stump of a rice plant (modern

variety) grown from a single seed with SRI management

methods -- having 223 tillers &

massive root growth

Panda’an, E. Java, 2009

IRAQ: Comparison trials at Al-Mishkhab Rice Research Station, Najaf

SRI

0

50

100

150

200

250

300

IH H FH MR W R YRStage

Org

an d

ry w

eig

ht(

g/h

ill)

IH H FH MR WR YR

CK Yellow leafand sheath

Panicle

Leaf

Sheath

Stem

47.9% 34.7%

Non-Flooding Rice Farming Technology in Irrigated Paddy Field Dr. Tao Longxing, China National Rice Research Institute, 2004

Results of trials conducted by the China National Rice Research Institute over two years, 2004/2005, using 2 super-hybrid varieties with an intention to break the ‘yield plateau’ now limiting hybrids

Standard Rice Mgmt

• 30-day seedlings

• 20x20 cm spacing

• Continuous flooding

• Fertilization:

– 100% chemical

New Rice Mgmt (~ 75% ‘SRI’)

• 20-day seedlings

• 30x30 cm spacing

• Alt. wetting/drying (AWD)

• Fertilization:

– 50/50 chemical/organic

X.Q. Lin, D.F. Zhu, H.Z. Chen, S.H. Cheng and N. Uphoff (2009). “Effect of

plant density and nitrogen fertilizer rates on grain yield and nitrogen uptake of hybrid rice (Oryza sativa L.)” Journal of Agricultural

Biotechnology and Sustainable Development, 1(2): 44-53

Average yields of (kg/ha) hybrid varieties with ‘new rice management’ vs. standard rice

management at different plant densities per ha

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

150,000 180,000 210,000

NRM

SRM

Plant population per hectare

SRI practices yield more productive phenotypes -- Chinese farmers are WASTING seeds and water and N fertilizer

SRI methods have set a new world yield record

Paddy production: Bihar

panchayat breaks China’s record New Delhi, Mar 20: A gram panchayat in Nalanda district of Bihar has

surpassed the Chinese record of paddy production,

the Union Agriculture Minister Mr Sharad Pawar

informed Parliament today. “As per the reports

received from the state government, the yield of wet

paddy has been recorded at 22.4 tonnes per hectare

and that of dry paddy at 20.16 tonnes a hectare ...,”

Mr Pawar said in a written reply to Lok Sabha.

The record yield was achieved under demonstration

on System of Rice Intensification (SRI) which was

organised at farmer’s field during kharif 2011, he

added. “It has surpassed the yield of 19 tonnes per

hectare which was recorded earlier in China.”

Before 1999: Madagascar 1999-2000: China, Indonesia 2001-02: Bangladesh, Cuba, Laos, Cambodia, Gambia, India, Nepal, Myanmar, Philippines, Sierra Leone, Sri Lanka, Thailand 2003: Benin, Guinea, Mozambique, Peru 2004-05: Senegal, Pakistan, Vietnam 2006: Burkina Faso, Bhutan, Iran, Iraq, Zambia

2007: Afghanistan, Brazil, Mali

2008: Rwanda, Costa Rica, Egypt, Ecuador, Ghana, Japan

2009: Malaysia, Timor Leste

2010: Kenya, DPRK, Panama, Haiti

2011: Colombia, Korea, Taiwan, Tanzania

2012: Burundi, Dominican Republic, Niger, Nigeria, Togo

2013: Malawi, Cameroon

2013: SRI’s phenotypic benefits have been seen now in >50 countries of Asia, Africa, and Latin America

These changes in crop management can be effective in very different and

quite contrasting agroecosystems:

* AFGHANISTAN: Baghlan province 1600 masl, temperate climate, with a short growing season

* MALI: Timbuktu province

on the edge of the Sahara Desert, with hot, dry subtropical climate

AFGHANISTAN: SRI field in Baghlan Province, supported by Aga Khan Foundation Natural Resource Management program

AKF technician making a field visit in Baghlan province

SRI field at 30 days

SRI plant @ 72 days after transplanting

with 133 tillers 11.56 t/ha

2008: 6 farmers got SRI yields of 10.1 t/ha vs. 5.4 t/ha regular methods 2009: 42 farmers got SRI yields of 9.3 t/ha vs. 5.6 t/ha with regular methods - 2nd year SRI farmers got

13.3 t/ha vs. 5.6 t/ha - 1st year SRI farmers got

8.7 t/ha vs. 5.5 t/ha 2011: 106 farmers got SRI yields of 10.1 t/ha vs. 5.04 t/ha with regular methods

All were using less water

MALI -- SRI nursery in Timbuktu region – 8-day seedlings are ready for transplanting

SRI transplanting on edge of Sahara Desert

Mali farmer working with the NGO Africare

in Timbuktu region with support from BUF,

showing difference between rice plants: regular (left) and SRI

2007/08: 1 farmer -

SRI yield of 8.98 t/ha 2008/09: 60 farmers -

9.01 vs. 5.49 t/ha 2009/10: 130 farmers –

7.71 vs. 4.48 t/ha using 32% less water

Gao region ave.: 7.84 t/ha

Mopti region ave.: 7.85 t/ha

Environmental Benefits with SRI: 1. Reduced water requirements – higher crop water-use

efficiency -- puts less pressure on ecosystems in competition with agriculture for water supplies

2. Higher land productivity – reducing pressures for the expansion of arable area to feed growing populations

3. Less use of inorganic fertilizer – reactive N is “the third major threat to our planet after biodiversity loss and climate change” (John Lawton, former chief executive, UK National Environmental Research Council)

4. Less reliance on agrochemicals for crop protection - which enhances the quality of both soil and water

5. Buffering against the effects of climate change – drought, storms (resist lodging), cold temperatures

6. Some reduction in greenhouse gases (GHG) – CH4 can be reduced without producing offsetting N2O

Other Benefits from Changes in Practices

1. Water saving – major concern in many places, also now have ‘rainfed’ version with similar results

2. Greater resistance to biotic and abiotic stresses – less damage from pests and diseases, drought, typhoons, flooding, cold spells [discuss tomorrow]

3. Shorter crop cycle – same varieties are harvested by 1-3 weeks sooner, save water, less crop risk

4. High milling output – by about 15%, due to fewer unfilled grains (less chaff) and fewer broken grains

5. Reductions in labor requirements – widely reported incentive for changing practices in India and China; also, mechanization is being introduced many places

6. Reductions in costs of production – greater farmer income and profitability, also health benefits

Drought-resistance: Rice fields in Sri Lanka 3 weeks after irrigation stopped because of drought -- conventionally-grown field is on left,

and SRI field is on right-- same variety, same soil, same climate

Results from Bihar State, 2007-2011 Data from Bihar Rural Livelihood Promotion Society, Govt. of Bihar

SYSTEM OF RICE INTENSIFICATION -- state ave. 2.3 t/ha

2007 2008 2009 2010

Climatic conditions Normal rainfall

Water submergence occurred 2x

Drought, but rainfall in

Sept.

Complete drought

No. of smallholders 128 5,146 8,367 19,911

Area under SRI (ha) 30 544 786 1,412

SRI yield (t/ha) 10.0 7.75 6.5 3.22*

Conv. yield (t/ha) 2.7 2.36 2.02 1.66*

,

SYSTEM OF WHEAT INTENSIFICATION -- state ave. 2.4 t/ha

2008-09 2009-10 2010-11

No. of smallholders 415 25,235 48,521

Area under SWI (ha) 16 1,200 2,536

SWI average yield (t/ha) 3.6 4.5 NA

Conv. average yield (t/ha) 1.6 1.6 NA

* Results from measurements of yield on 74 farmers’ SRI and conventional fields

Year 2004 2005 2006 2007 2008 2009 2010 Total

SRI area (ha) 1,133 7,267 57,400 117,267 204,467 252,467 301,067 941,068

SRI yield (kg/ha) 9,105 9,435 8,805 9,075 9,300 9,495 9,555 9,252

Non-SRI yield (kg/ha) 7,740 7,650 7,005 7,395 7,575 7,710 7,740 7,545

SRI increment (t/ha)* 1,365 1,785 1,800# 1,680 1,725 1,785 1,815# 1,708

SRI % increase in yield* 17.6% 23.3% 25.7% 22.7% 22.8% 23.2% 23.5% 22.7%

Increased grain (tons） 1,547 12,971 103,320 197,008 352,705 450,653 546,436 1,664,640

Grain price (RMB

Yuan/kg) 1.44 1.44 1.44 1.50 1.80 1.84 1.95 1.63

Added net income due

to SRI (million RMB)* 1.28 11.64 106.51 205.10 450.85 571.69 704.27

2,051

($300 m)

* Comparison is with Sichuan provincial average for paddy yield and SRI profitability # In drought years, SRI yields were relatively higher than with conventional methods Source: Data are from the Sichuan Provincial Department of Agriculture.

CHINA: SRI extension and impact in Sichuan, 2004-10

Storm resistance: Adjacent fields

after being hit by a tropical storm

in Dông Trù village, Hanoi province,

Vietnam

On left are SRI field

and rice plant; on right, conventional

field and plant

Same variety was used in both fields -- on right, we see serious lodging;

on left, no lodging

Incidence of diseases and pests in Vietnam: National IPM Program evaluation -- averages of data from on-farm trials in 8 provinces, 2005-06:

Spring season Summer season

SRI plots

Farmer plots

Differ-ence

SRI plots

Farmer Plots

Differ-ence

Sheath blight

6.7% 18.1% 63.0% 5.2% 19.8% 73.7%

Leaf blight -- -- -- 8.6% 36.3% 76.5%

Small leaf folder *

63.4 107.7 41.1% 61.8 122.3 49.5%

Brown plant hopper *

542 1,440 62.4% 545 3,214 83.0%

AVERAGE 55.5% 70.7%

* Insects/m2

Resistance to both biotic and abiotic stresses: fields were hit by both brown planthopper (BPH) and by storm damage in Indonesia – the rice field on left was grown with standard

practices, while the field on the right is organic SRI

Modern improved

variety (Ciherang) – no yield

Traditional aromatic variety

(Sintanur) - 8 t/ha

Comparison of methane gas emission

CT SRI

kg C

H4 / h

a

0

200

400

600

800

1000

840.1

237.6

72 %

Treatment Emission (kg/ha) CO2 ton/ha

equivalent CH4 N2O

CT 840.1 0 17.6

SRI 237.6 0.074 5.0

SRI practices are now being used beyond rice, for broader System of Crop Intensification (SCI)

Farmer-led innovations with civil society help in:

• Wheat (SWI) -- India, Nepal, Ethiopia, Mali

• Sugarcane (SSI) -- India, Cuba

• Finger millet (SFMI) -- India, Ethiopia

• Mustard (rapeseed/canola) -- India

• Teff -- Ethiopia

• Sorghum – Ethiopia

Also: maize, soya bean, black gram, green gram, red gram, tomatoes, chilies, eggplant, sesame, turmeric, etc. -- India, Ethiopia

Crops Yield increase

Profitability per ha

Rice 86% 250%

Wheat 72% 86%

Oil seeds 50% 93%

Pulses 56% 67%

Vegetables 20% 37% Enhancing Agricultural Livelihoods through

Community Institutions in Bihar, India (2013) D. Behera et al., World Bank India Office,

New Delhi, and JEEVIKA, Patna, India

Report on System of Crop Intensification (SCI) results in the Indian state of Bihar

System of Wheat Intensification on-farm trials in Tigray Province, Ethiopia, 2009-10,

supported by a grant from Oxfam America to Institute for Sustainable Development (ISD)

-- 39 grains vs. 56 grains per panicle

SWI results in Mali (1st year) Africare program, 2009

• Seed reduction: 94% (10 vs 170 kg/ha)

• Yield increase: 10% (2.2 vs 2.0 t/ha)

• Labor reduction: 40% • Irrigation water reduction: 30% • Problems: mortality, spacing was too

wide (25cm x 25cm 20 x 20 cm)

SWI: 10.2 cm Traditional: 4.2 cm Panicle length: Numbers of tillers

18.4 3.7

Panicles of SWI wheat in Bihar, India

In 2012, area with SWI management >180,000 ha, aided

by JEEVIKA program with WB/IDA support

ICRISAT-WWF Sugarcane Initiative: • 20-100% more cane yield, with

• 30% reduction in water, and

• 25% reduction in chemical inputs

“The inspiration for putting

this package together is from the successful

approach of SRI – System of Rice Intensification.”

System of Teff Intensification

(STI) in Ethiopia now supported by the government’s

Agricultural Transformation

Agency (ATA) and BMGF

Transplanted teff on left; conventional

broadcast teff on right

7,000 farmers in 2012, plus 160,000 farmers practicing STI ‘lite’

(drilled > transplanted)

These results do not argue against making further genetic improvements or against any use of external inputs

They do suggest, however, that progress can be made right now at low cost with savings of water and with buffering against climate

change -- by changing crop management practices, especially by attending to the

purposeful nurturing of roots and soil biota

WHAT IS GOING ON?

Two practical conclusions: 1. Instead of focusing so much on

‘feeding the plant’ (with fertilizer), we should be ‘feeding the soil’

with organic matter, so that the soil system will feed the plant 2. Rather than focus so much on growing plants (above ground),

we should do whatever is needed to grow roots! -- because it is the root systems that grow the plant

With SRI/SCI we see the importance of the abundance, diversity and activity of beneficial SOIL ORGANISMS promoted by soil organic matter and by exudates

from large, functioning ROOT SYSTEMS which support plant growth and health

We are just starting to understand

better the contributions of symbiotic endophytes to mobilizing the services for crops of the plant-soil microbiome

Soil-aerating hand weeder in Sri Lanka costing <$20

Effects of ‘Active Soil Aeration’

412 farmers in Morang district of Nepal when using SRI in monsoon season, 2005

SRI yield = 6.3 t/ha vs. control yield = 3.1 t/ha

Data show how WEEDINGS can raise yield

No. of No. of Average Range

weedings farmers yield of yields

1 32 5.16 (3.6 - 7.6)

2 366 5.87 (3.5 - 11.0)

3 14 7.87 (5.85 - 10.4)

No. of mech.

weedings

Farmers

(N)

Area

(ha)

Harvest

(kg)

Yield

(t/ha)

0 2 0.11 657 5.973

1 8 0.62 3,741 7.723

2 27 3.54 26,102 7.373

3 24 5.21 47,516 9.120

4 15 5.92 69,693 11.772

Impact of weedings on yield with SRI methods in Ambatovaky, Madagascar, 1997-98

ENDOPHYTIC AZOSPIRILLUM, TILLERING, AND RICE YIELDS WITH CULTIVATION

PRACTICES AND NUTRIENT AMENDMENTS Replicated trials at Anjomakely, Madagascar, 2001 (Andriankaja, 2002)

CLAY SOIL Azospirillum in roots

(103 CFU/mg)

Tillers/ plant

Yield (t/ha)

Traditional cultivation, no amendments

65 17 1.8

SRI cultivation, with no amendments

1,100 45 6.1

SRI cultivation, with NPK amendments

450 68 9.0

SRI cultivation, with compost

1,400 78 10.5

LOAM SOIL SRI cultivation with no amendments

75 32 2.1

SRI cultivation, with compost

2,000 47 6.6

Microbial populations in rice rhizosphere Tamil Nadu Agricultural University research

Microorganisms Conventional

management

SRI management

Total bacteria 88 x 106 105 x 106 (20% more)

Azospirillum 8 x 105 31 x 105 (~4x more)

Azotobacter 39 x 103 66 x 103 (~2x more)

Phosphobacteria 33 x 103 59 x 103 (~2x more)

T. M. Thiyagarajan, WRRC presentation, Tsukuba, Japan, 2004

Total bacteria Total diazotrophs

Microbial populations in rhizosphere soil of rice crop under different management at active tillering, panicle initiation, and flowering (conv. = red; SRI = yellow). Units are √ transformed values of population/gram of dry soil (data from IPB)

Phosphobacteria \

Azotobacter

0

10

20

30

40

Dehydrogenase activity (μg TPF) Urease activity (μg NH4-N))

Microbial activity in rhizosphere soil of rice crop under different management (conv. = red; SRI = yellow) at active tillering, panicle initiation, and flowering stages

Units are √ transformed values of population/gram of dry soil per 24 h

Acid phosphate activity (μg p-Nitrophenol) \

Nitrogenase activity (nano mol C2H4)

Total microbes and numbers of beneficial microbes (CFU mg-1) under conventional and SRI cultivation methods, Tanjung Sari, Indonesia, Feb.-Aug. 2009 (Iswandi et al., 2009)

Cultivation method and fertilization

Total microbes

(x105)

Azoto-bacter (x103)

Azospi- rillum (x103)

P-solubilizing bacteria

(x104)

Conventional mgmt (NPK) 2.3a 1.9a 0.9a 3.3a

Inorganic SRI (with NPK) 2.7a 2.2a 1.7ab 4.0a

Organic SRI (compost) 3.8b 3.7b 2.8bc 5.9b

Inorganic SRI + biofertilizer 4.8c 4.4b 3.3c 6.4b

These results suggest the importance of

studying and understanding the

contributions that are made by

symbiotic endophytes

(aka endophytic symbionts) – major

parts of the plant-soil microbiome

“Ascending Migration of Endophytic Rhizobia, from Roots and Leaves, inside Rice Plants and Assessment of

Benefits to Rice Growth Physiology”

Feng Chi et al., Applied and Envir. Microbiology 71: 7271-7278 (2005)

Rhizo-bium strain

Total plant root vol/pot

(cm3) ± SE

Shoot dry wt/pot

(g) ± SE

Net photosyn- thesis rate

(µmol of CO2 m-2 s-1) ± SE

Water utilization efficiency

± SE

Grain yield/pot

(g) ± SE

Ac-ORS 571

210 ± 36A

63 ± 2A

16.42 ± 1.39A

3.63 ± 0.17BC

86 ± 5A

Sm-1021 180 ± 26A

67 ± 5A

14.99 ± 1.64B

4.02 ± 0.19AB

86 ± 4A

Sm-1002 168 ± 8AAB

52 ± 4BC

13.70 ± 0.73B

4.15 ± 0.32A

61 ± 4B

R1-2370 175 ± 23A

61 ± 8AB

13.85 ± 0.38B

3.36 ± 0.41C

64 ± 9B

Mh-93 193 ± 16A

67 ± 4A

13.86 ± 0.76B

3.18 ± 0.25CD

77 ± 5A

Control 130 ± 10B

47 ± 6C

10.23 ± 1.03C

2.77 ± 0.69D

51 ± 4C

“Proteomic analysis of rice seedlings infected by Sinorhizobium meliloti 1021”

Feng Chi et al., Proteomics 10: 1861-1874 (2010)

Data are based on the average linear root and shoot growth of three symbiotic (dashed line) and three nonsymbiotic (solid line) plants.

Arrows indicate the times when root hair development started.

Ratio of root and shoot growth in symbiotic and

nonsymbiotic rice plants -- seeds were inoculated with the fungus Fusarium culmorum vs. controls R. J. Rodriguez et al., ‘Symbiotic regulation of plant growth,

development and reproduction” Communicative and Integrative Biology, 2:3 (2009).

Growth of nonsymbiotic (on left) and symbiotic (on right) rice seedlings. On the growth of endophyte (F. culmorum) and plant inoculation procedures, see Rodriguez et al., Communicative and Integrative Biology, 2:3 (2009).

More productive phenotypes also can give higher water-use efficiency as measured by the ratio of photosynthesis to transpiration

For each 1 millimol of water lost by transpiration:

3.6 millimols of CO2 are fixed in SRI plants,

1.6 millimols of CO2 are fixed in RMP plants

This becomes more important with climate change

“An assessment of physiological effects of the System of Rice Intensification (SRI) compared with recommended rice cultivation

practices in India,” A.K. Thakur, N. Uphoff and E. Antony Experimental Agriculture, 46(1), 77-98 (2010)

Economics, environmental vulnerabilities, and climate change effects will require a

different kind of agriculture in 21st century.

Suggest we RE-BIOLOGIZE AGRICULTURE

We need an understanding of agriculture that is more informed by microbiology, crop physiology,

soil ecology, and epigenetics – which are becoming more prominent in our contemporary science

Closing thought: Darwin’s ‘tree of life’ was good taxonomy, but not very good biology

-- We never left the microbes behind…

THANK YOU

Web page: http://sri.ciifad.cornell.edu/ Email: ntu1@cornell.edu [NTU-one]