Learning about positive plant-microbial

interactions from the System of Rice

Intensification (SRI)Conference of Association of Applied

Biologists on Positive Plant-Microbial InteractionsGrantham, UK, December 15-16, 2009

Norman Uphoff, CIIFAD, Cornell University, USAIswandi Anas, Biotechnology Lab, IPB, IndonesiaO.P. Rupela, former Principal Scientist, ICRISAT,

IndiaA.K. Thakur, Directorate of Water Management,

IndiaT.M. Thiyagarajan, Tamil Nadu Agric. Univ., India

SRI: a methodology developed for raising rice yields in

Madagascar1. Introduction to SRI – can see positive

effects of altering management practices

2. Evidence of the phenotypical effects of SRI practices, and of epigenetic effects?

3. Madagascar data suggesting positive contributions of soil microbial populations

4. SRI changes in soil microbial populations

5. Contributions to rice from endophytic symbiotic microbes, both bacteria and fungi

SRI does not rely on either the introduction of improved varieties

or application of external inputs• SRI changes the way that rice plants, soil, water and nutrients are managed

• To get more productive PHENOTYPES from any and all rice GENOTYPES

• Changes in plant morphology – numbers of tillers, root system growth, leaf area, angle of tillers, etc.

• Changes in plant physiology – water-use efficiency, root exudation, rates of photosynthesis, delayed senescence, etc.

• Indications of EPIGENETIC changes to be explored – contribution from plant-microbial interactions?

CUBA: farmer with two plants of same variety

(VN 2084) and same age (52 DAP)

CAMBODIA: Rice plant

grown from single seed in

Takeo province

NEPAL:Single rice

plant grownwith SRI methods, Morang district

IRAN: SRI roots and normal

(flooded) roots: note difference in color as well as size

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

‘Rice Aplenty in Aceh’

(Indonesia)

CARITAS NEWSSpring 2009

SRI methods were introduced in Aceh in 2005 by CARITAS Australia after tsunami had

devastated the area – new methods raised local rice yields from 2 t/ha to 8.5 t/ha: “Using less

rice seed, less water and organic compost, farmers in Aceh have quadrupled their crop

production.”

2009 Report from Aga Khan

Foundation: Baghlan Province,

Afghanistan

2008: 6 farmers got SRI yields of 10.1 t/ha vs. 5.4 t/ha regular2009: 42 farmers got SRI yields of 9.3 t/ha vs. 5.6 t/ha regular

2nd-year SRI farmers got 13.3 t/ha vs. 5.6 t/ha1st-year SRI farmers got 8.7 t/ha vs. 5.5 t/ha

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

program

SRI field at 30 days

SRI plant with 133 tillers @

72 days after transplanting

11.56 t/ha

Report on SRI in Deorali Geog, BHUTAN, 2009

Sangay Dorji, Jr. Extension Agent, Deorali Georg, Dagana

SRI @ 25x25cm 9.5 t/ha SRI random spacing 6.0 t/ha

SRI @ 30x30cm 10.0 t/ha Standard practice 3.6 t/ha

Comparison of SRI and usual rice plants in

INDONESIA

Miyatty Jannah,

Crawuk village, Ngawi, E. Java

INDONESIA:Sampoerna CSR

Program,Malang, E. Java, 2009

Single SRI rice plantVariety: Ciherang

No. of fertile tillers: 223

I mproved variety of finger milletwith SRI methods (lef t); regular management of improved variety

(middle) and traditional variety (right)

Extensions of SRI to Other Crops: Extensions of SRI to Other Crops: Uttarakhand / Himachal Pradesh, India Uttarakhand / Himachal Pradesh, India

Crop No. of Farmers

Area (ha)

Grain Yield (t/ha)

%Incr.

2006 Conv. SRI

Rajma 5 0.4 1.4 2.0 43Manduwa 5 0.4 1.8 2.4 33Wheat Research

Farm5.0 1.6 2.2 38

2007

Rajma 113 2.26 1.8 3.0 67Manduwa 43 0.8 1.5 2.4 60Wheat (Irrig.)

25 0.23 2.2 4.3 95

Wheat (Unirrig.)

25 0.09 1.6 2.6 63

Rajma (kidney beans)

Manduwa (millet)

ICRISAT-WWF Sugarcane

Initiative: at least 20% 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.”

SRI Involves Only Changes in Practices

1. Transplant young seedlings to preserve their growth potential -- but DIRECT SEEDING is now an option

2. Avoid trauma to the roots -- transplant quickly and shallow, not inverting root tips which halts growth

3. Give plants wider spacing -- one plant per hill and in square pattern to achieve “edge effect” everywhere

4. Keep paddy soil moist but unflooded -- soil should be mostly aerobic -- not continuously saturated

5. Actively aerate the soil as much as possible6. Enhance soil organic matter as much as possible

First 3 practices stimulate plant growth, while the latter 3 practices enhance the growth and health of plants’ ROOTS and of soil BIOTA

Evidence of Phenotypical Effects of

SRI Practices

SRI LANKA: same rice variety, same irrigation system &same drought -- left, conventional methods; right, SRI

VIETNAM: Dông Trù village,Hanoi province,

after typhoon

Period Period Mean Mean max. max.

temp. temp. 00CC

Mean Mean min. min.

temp. temp. 00C C

No. of No. of sunshine sunshine

hrshrs

1 – 151 – 15 NovNov 27.727.7 19.219.2 4.94.9

16–3016–30 Nov Nov 29.629.6 17.917.9 7.57.5

1 – 15 Dec1 – 15 Dec 29.129.1 14.614.6 8.68.6

16–31 Dec 16–31 Dec 28.128.1 12.212.2** 8.68.6

India: Meteorological and yield data from ANGRAU IPM evaluation, Andhra Pradesh,

2006

SeasonSeason Normal (t/ha)Normal (t/ha) SRI (t/ha)SRI (t/ha)

Rabi 2005-06Rabi 2005-06 2.25 2.25 3.473.47

Kharif 2006Kharif 2006 0.21*0.21* 4.164.16

* Low yield was due to cold injury for plants (see above)

*Sudden drop in min. temp. during 16–21 Dec. (9.2-9.8oC for 5 days)

Nepal: Crop duration (from seed to seed) of rice varieties with SRI vs.

conventional methods – average no. of days: 125 vs. 141

Varieties Conventional duration

SRI duration Difference

Bansdhan/Kanchhi

145 127 (117-144)

18 (28-11)

Mansuli 155 136 (126-146)

19 (29- 9)

Swarna 155 139 (126-150)

16 (29- 5)

Sugandha 120 106 (98-112) 14 (22- 8)

Radha 12 155 138 (125-144)

17 (30-11)

Barse 3017 135 118 17

Hardinath 1 120 107 (98-112) 13 (22- 8)

Barse 2014 135 127 (116-125)

8 (19-10)

SRI

0

50

100

150

200

250

300

IH H FH MR WR YRStage

Org

an d

ry w

eigh

t(g/

hill)

CK

I H H FH MR WR YR

Yellowleaf andsheathPanicle

Leaf

Sheath

Stem

47.9% 34.7%

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

China National Rice Research Institute:

Factorial trials over two years, 2004/2005

using two super-hybrid varieties with the aim of breaking the ‘plateau’

limiting yieldsStandard Rice Mgmt• 30-day seedlings• 20x20 cm spacing• Continuous

flooding• Fertilization:

– 100% chemical

New Rice Mgmt (SRI)• 20-day seedlings• 30x30 cm spacing• Alternate wetting

and drying (AWD)• Fertilization:

– 50% chemical, – 50% organic

Average super-rice yields (kg/ha) with new rice

management (SRI) vs.standard rice management

at different plant densities ha-1

0100020003000400050006000700080009000

10000

150,000 180,000 210,000

NRMSRM

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, E. AntonyExperimental Agriculture, 46(1), 77-98 (2010)

Water-use efficiency is reflected in theratio of photosynthesis to transpiration

For the loss of 1 millimol of water by transpiration,

In SRI plants, 3.6 millimols of CO2 are fixed

In RMP plants, 1.6 millimols of CO2 are fixed

ParametersCultivation method

SRI RMP LSD.05

Total chlorophyll (mg g-1FW) 3.37 (0.17) 2.58 (0.21) 0.11

Chlorophyll a/b ratio 2.32 (0.28) 1.90 (0.37) 0.29

Transpiration (m mol m-2 s-1) 6.41 (0.43) 7.59 (0.33) 0.27Net photosynthetic rate (μ mol m-2 s-1)

23.15 (3.17)

12.23 (2.02)

1.64

Stomatal conductance (m mol m-2 s-1)

422.73 (34.35)

493.93 (35.93)

30.12

Internal CO2 concentration

(ppm)

292.6

(16.64)

347.0

(19.74)

11.1

Comparison of chlorophyll content, transpiration rate, net photosynthetic rate, stomatal

conductance, and internal CO2 concentration in SRI and RMP

Standard deviations are given in parentheses (n = 15).

Data from Madagascar Suggested Contributions

of Soil Microbial Populations and Plant-

Microbial Interactions for Explaining SRI Effects

ENDOPHYTIC AZOSPIRILLUM, TI LLERING, AND RICE YIELDS WITH CULTIVATION PRACTICES AND NUTRIENT AMENDMENTS Replicated trials at Anjomakely, Madagascar, 2001 (Andriankaja, 2002)

Azospirillum No. of CLAY SOIL in roots

(103/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

Effects of Active Soil Aeration with Mechanical

WeederMechanical Weedings

(N) Yield (t ha-1)

MADAGASCAR: 1997-98 main season -- Ambatovaky (N=76)

None 2 5.97One 8 7.72Two 27 7.37

Three 24 9.12Four 15 11.77

NEPAL: 2006 monsoon season – Morang district (N=412)One 32 5.16

(3.6 – 7.6)

Two 366 5.87(3.5 – 11.0)

Three 14 7.87(5.85 – 10.4)

SRI Management Practices Can Modify

Soil Microbial Populations

Microbial populations in rice rhizosphere

Tamil Nadu Agricultural University research

Microorganisms

Conventional

SRI

Total bacteria 88 x 106 105 x 106

Azospirillum 8 x 105 31 x 105

Azotobacter 39 x 103 66 x 103

Phosphobacteria

33 x 103 59 x 103

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

Total bacteria Total diazotrophs

Microbial populations in rhizosphere soil in rice crop under different management at active tillering, panicle initiation and flowering (SRI = yellow; conventional = red)

[units are √ transformed values of population/gram of dry soil]

Phosphobacteria \ Azotobacter

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

Microbial activities in rhizosphere soil in rice crop under different management (SRI = yellow; conventional = red) 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 g-1) under conventional and

SRI cultivation methods, Tanjung Sari, Bogor, 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 crop mgmt with NPK

2.3a 1.9a 0.9a 3.3a

Inorganic SRI (NPK fertilizer)

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

Endophytic Symbiotic Microbes (both Bacteria and Fungi) Contribute to Rice Plant Productivity --

and Not Only in Rhizosphere

May or may not apply to SRI, which is still ‘a work in

progress’

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 (2005),

7271-7278Rhizo-bium test strain

Total plant root

volume/pot (cm3)

Shoot dry weight/ pot (g)

Net photo-synthetic

rate (μmol-2 s-1)

Water utilization efficiency

Area (cm2) of flag leaf

Grain yield/ pot (g)

Ac-ORS571 210 ± 36A 63 ± 2A 16.42 ± 1.39A 3.62 ± 0.17BC 17.64 ± 4.94ABC 86 ± 5A

SM-1021 180 ± 26A 67 ± 5A 14.99 ± 1.64B 4.02 ± 0.19AB 20.03 ± 3.92A 86 ± 4A

SM-1002 168 ± 8AB 52 ± 4BC 13.70 ± 0.73B 4.15 ± 0.32A 19.58 ± 4.47AB 61 ± 4B

R1-2370 175 ± 23A 61 ± 8AB 13.85 ± 0.38B 3.36 ± 0.41C 18.98 ± 4.49AB 64 ± 9B

Mh-93 193 ± 16A 67 ± 4A 13.86 ± 0.76B 3.18 ± 0.25CD 16.79 ± 3.43BC 77 ± 5A

Control 130 ± 10B 47 ± 6C 10.23 ± 1.03C 2.77 ± 0.69D 15.24 ± 4.0C 51 ± 4C

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 -- symbiotic plant seeds were inoculated with Fusarium culmorum

Russell 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 growth of endophyte (F. culmorum) and plant

inoculation procedures, see Rodriguez et al., Communicative and Integrative Biology, 2:3 (2009).

SRI is pointing the way toward an emerging paradigm shift in the agricultural sciences:• Less genocentric and more fundamentally biocentric• More interest in epigenetics• Re-focus biotechnology and bioengineering to capitalize on benefits of biodiversity and ecological dynamics• Less chemical-dependent and more energy-efficient• More oriented to health of humans and the environment•Intensification of production• Focus on greater factor productivity and sustainability