Individual and combined effect of management components of SRI on

the productivity of irrigated rice

R. Rajendran*, V. Ravi, N.Chelliah, and V. Balasubramanian

* Professor (Agronomy), Tamil Nadu Rice Research Institute (TNAU), Aduthurai, India

SRI Modified SRI

• Management practices tailored to the local conditions

• Practiced in different names - countries/region

• As “modified SRI” in Tamil Nadu

Initiated from 2002 in Cauvery Delta, Tamil Nadu

Practices recommended for SRIPractices recommended for SRI

Practices

Seedling age (days) 15

Seedlings per hill 1

Plant spacing (cm) 22.5 x 22.5

Planting geometry Square

Mechanical weeding/soil stirring

Two cono/rotary weeder

+ one HW (no herbicide)

Intermittent irrigation

2.5 cm up to flowering intermittently

Nutrient application OM + fertilizers

Objectives

n To study the individual effect of SRI

components on rice productivity

n To study the synergistic effect of SRI

practices

n To assess the factor productivity in SRI

Experimental details

Locations (2) : TRRI, Aduthurai, TN, India

SWMRI, Thanjavur, TN, India

Year : 2002 - 2004

Variety : ADT- R 45 (110 d )

Design : CRBD

Replication : 3

Treatments : 13

Treatment details

YOSCI (SRI)

YOSCF

YOSHI

YORHI

YMSCI

AOSCI

AMRHI

YMRHI

AORHI

AOSHI

AMSCI

AMSHI

AMRHF (conventional)

Y - Young seedling (15 d )

A - Aged seedling (25 d)

O - One seedling/hill

M - Multiple seedlings hill-1

S - Square planting (22.5 x 22.5cm)

R - Row planting (15x10 cm)

C - Cono weeding

H - Hand weeding

I - Intermittent irrigation

F - Flooding

7304

5646

0

2000

4000

6000

8000

GY

(kg

/ha)

MSRI Nointercultivation

CM

Rice grain yield as influenced by intercultivation with cono weeder

TRRI, Aduthurai

Yield enhanced by 29%

7500

5140

0

2000

4000

6000

8000

GY

(kg/

ha)

MSRI Nointercultivation

CM

Rice grain yield as influenced by intercultivation with cono weeder

SWMRI, Thanjavur

Yield enhanced by 46%

Impact of inter-cultivation on yield, Cauvery Delta, Tamil Nadu, 2002-04

Impact of SRI +SSNM on irrigated rice productivity, Cauvery Delta,

Kharif and rabi 2003- 04

0

2

4

6

8

F 0 LCC-N + K

3.4

5.6 5.9

3.9

6.5 6.8

Grain

yield

(t/h

a)

Treatments

Impact of modified SRI and SSNM on irrigated rice

Conventional

Modified SRI

Prob >F : F0, 0.07; LCCN, 0.02 and +K, 0.02

Rajendran et al., 2006

Dominating Pests -- Leaf folder

Impact of SRI on pest incidenceImpact of SRI on pest incidence

Detail No. of valid

seasons

Conven-tional

planting

SRI method of planting

Pest incidence

Whorl maggot (%LD)

511.56 4.82

Leaf folder (% LD) 8 12.97 21.04

Gall midge (% DT) 2 4.52 2.72

BPH (no./hill) 4 7.52 1.84

Stem borer (% DT) 6 9.86 5.48

Crop yield (kg/ha)

Grain yield 8 5,127 6,986

Ravi et al., 2006

SRI + SSNM on N use efficiency, Cauvery Delta, Kharif and Rabi, 2003-04

Prob > F : For LCC-N & + K, 0.02

25.7 28.5

05

10

15202530

LCC-N + K

Treatments

Conventional

Modif ied SRI

Rajendran et al., 2006

Management / Variety

Chlorophyll

(a: b ratio)ADT 43 ADT RH 1

Conv. + flooding 1.27:1 1.21:1

Conv. + intermittent irrigation

1.33:1 1.43:1

SRI + flooding 1.52:1 1.34:1

SRI + intermitt. irrig. 1.56:1 1.59:1

Components of chlorophyll as influenced by SRI practices, Kharif, 2005*

* Mean data

Treatments Root length (cm) Root volume (cc)

ADT 43 PHB 71 ADT 43 PHB 71

Conv. + flooding 11.6 12.0 21.8 19.3

Conv. + inter. irrig. 15.2 15.1 23.3 26.3

SRI + flooding 16.3 16.1 37.7 39.2

SRI + inter. irrig. 16.5 16.5 51.0 57.7

CD (5%) 0.7 4.0

Root growth as influenced by SRI (inter-cultivation), Kharif, 2006*

* On-going experiment

Nutrient uptake (kg/ha), TRRI Farm, Cauvery Delta, Kharif, 2005*

Treatment Grain Straw

N P K N P K

Conventional 57.0 7.9 8.7 32.6 5.9 68.7

SRI 74.1 11.0 11.3 43.7 7.8 87.0

C.D. (5%) 4.4 0.7 1.5 4.2 1.3 10.4

* On-going research project

TRRI, Aduthurai

Yield reduced by 23%

SWMRI, Thanjavur

Yield reduced by 18%

Impact of older seedling age, Cauvery Delta, Tamil Nadu, 2002 -04

7304

5632

010002000300040005000600070008000

GY (k

g/ha

)

MSRI Aged seedling

CM

Rice grain yield as influenced by aged seedling effect

75006163

0

1000

2000

3000

4000

5000

6000

7000

8000

GY (k

g/ha

)

MSRI Aged seedling

CM

Rice grain yield as influenced by aged seedling effect

Seedling age

Aduthurai Thanjavur

Panicles/m2

GY

(kg/ha)

B:C Panicles/m2

GY

(kg/ha)

B:C

Traditional nursery – 25 days

377 5874 2.6 344 5557 1.9

Modified mat nursery

15 days

452 7061* (20)

3.2 424 6583* (16)

2.7

C.D (5%) 25 163 n. a 21 121 n. a

Rajendran et al., 2005

Seedling age on rice productivity and profit, Cauvery Delta, Tamil Nadu, Rabi, 2002-03

* % yield increase over aged seedling

Influence of seedling age when planted, based on leaf number, Cauvery Delta, Kharif 2006 & Kharif 2007 (in progress)

No. of leaves per

seedling

Panicles / sq. m

ADT 43 PHB 71 Seedling mean

2 391 404 398

3 438 456 447

4 397 423 410

5 350 402 376

Cultivar mean 403 425

C.D. (5%) 10 15

Panicle production

No. of leaves per

seedling

Grain yield (kg/ha)

ADT 43 PHB 71 Seedling mean

2 7595 7903 7749

3 9198 9457 9327

4 8016 8762 8889

5 7297 8299 7798

Cultivar mean 8277 8598

C.D. (5%) 145 230

Rice grain yield

7304

6094

5000

5500

6000

6500

7000

7500

GY (k

g/ha

)

MSRI Flooding

CM

Rice yield as influenced by flooding

TRRI, Aduthurai

Yield reduced by 17%

SWMRI, Thanjavur

Yield reduced by 16%

Impact of flooding, Cauvery Delta, Tamil Nadu 2002 -04

7500

6285

5500

6000

6500

7000

7500

GY (k

g/ha)

MSRI Flooding

CM

Rice yield as influenced by flooding

4836

7304

0

1000

2000

3000

4000

5000

6000

7000

8000

GY

(kg/

ha)

Conventional M SRI

CM

5152

7500

0

1000

2000

3000

4000

5000

6000

7000

8000

GY

(kg/

ha)

Conventional M SRI

CM

Synergistic effect of SRI on rice productivity, Cauvery Delta, Tamil Nadu, 2002 - 04

TRRI, Aduthurai

Yield enhanced by 51%

SWMRI, Thanjavur

Yield enhanced by 46%

Input use/cost Aduthurai Thanjavur

SRI Conven. SRI Conven.

Nursery cost efficiency

(Rs./kg grain)

0.21 0.66 0.21 0.62

Water use (m3) 8,964 14,193 11,952 15,687

Water use efficiency (kg grain m-3 water)

0.81 0.34 0.63 0.33

Factor productivity for SRI and conventional rice cultivation, kharif and rabi, Cauvery Delta,

Tamil Nadu, 2002-04

Input use/cost Aduthurai Thanjavur

SRI Conven. SRI Conven.

Fertilizer cost efficiency (Rs./kg grain)

0.64 1.01 0.62 0.93

Weeding cost efficiency (Rs./kg grain)

0.20 0.31 0.19 0.29

Factor productivity for SRI and conventional rice cultivation, kharif and rabi, 2002- 04, Cauvery

Delta, Tamil Nadu

Targeted yield attributes for enhanced grain yield in SRI

Yield attributes Role of M SRI

1. No. of panicles/m2

2. No. of grains/panicle

3. No. of spikelets/panicle

Genotypic potential of rice plant tapped through:

Improved crop establishment

Soil stirring by cono-weeder

Intermittent irrigation

Synergistic effect of all

SRI components

Targeted yield attributes for enhanced grain yield in SRI

Yield attributes Role of Modified SRI

3. Increased no. of spikelets/panicle

Genotypic potential tapped through

Improved grain filling which resulted in more grain weight than with traditional planting

Treatments Grain

length (mm)

Grain

width

(mm)

Kernel

length

(mm)

Kernel

width

(mm)

Conventional 8.79 2.38 6.39 1.99

SRI 8.85 2.41 6.51 1.98

C.D. (5%) 0.09 0.04 0.08 0.04

Improved grain quality in SRI

Cauvery Delta, Kharif, 2005

What to do?

For farmer-friendly and faster adoption of SRI:

• Strengthening of nursery & water management practices through community approach

• Training of farmers and farm labourers in square planting

• Mechanization of inter-cultivation

• Increasing awareness on healthy nutrient management, especially for N management

Key is the healthy crop establishment