Transcript Opportunities for Rice Research and Production

The System of Rice
Intensification (SRI):
Capitalizing on Existing Yield Potentials
by Changing Management Practices
to Increase Rice Productivity with
Fewer Inputs and More Profitability
Norman Uphoff, Cornell International Institute
for Food, Agriculture and Development (CIIFAD)
World Rice Research Conference, Nov. 7, 2004
What Is SRI?
A set of principles & methods to get
more productive PHENOTYPES
from any existing GENOTYPE of rice
This is accomplished with SRI methods
(a) by inducing greater ROOT GROWTH,
and (b) by nurturing more abundant and
diverse populations of SOIL BIOTA -through changing the management of
plants, soil, water, and nutrients
For Centuries, Even Millennia:
• We have FLOODED rice plants, drowning
their roots and causing roots to degenerate
• We have CROWDED plants, inhibiting the
growth potential of their shoots and roots
• We now apply various FERTILIZERS and
AGROCHEMICALS that affect the soil biota
• These provide many services to rice plants:
N fixation, P solubilization, protection
against diseases and abiotic stresses, etc.
• Standard practices interfere with these benefits
Different Paradigms of Production:
• The GREEN REVOLUTION paradigm:
(a) Changed the genetic potential of plants, and
(b) Increased the use of external inputs – with
more water, more fertilizer, insecticides, etc.
This succeeded, but at fairly high (growing) cost
• SRI just changes the way that farmers manage
their plants, soil, water and nutrients, reducing
water use and costs of production while raising
factor productivity and farmers’ income
• These benefits result from (a) promoting the
growth of root systems, and (b) increasing the
abundance and diversity of soil organisms,
which in turn contribute to plant productivity
SRI Sounds ‘Too Good to be True’ –
But It Is True, as seen from papers
• These countries represent over 2/3 of the
world’s production/consumption of rice
No longer any question whether SRI works
• SRI practices change the E in the G x E
equation: get more productive phenotypes
• But there is still much about SRI that is
not well understood – work in progress
• Many opportunities for scientific work on
soil biology, plant physiology and nutrition,
genetic signaling, disease resistance, etc.
Cambodian farmer
with rice plant grown
from single seed,
using SRI methods
and traditional variety
Comparison of Dry Matter Accumulation
(kg ha-1) for SRI vs. Control (CK) Practices
at Maturity (Zheng et al., SAAS, 2003)
30000
25000
20000
15000
SRI
CK
10000
5000
0
Stem
Sheath
Green
Leaf
With.
Leaf
Panicle Biomass
Figure 1. Change of leaf area index (LAI)
during growth cycle (Zheng et al., 2003)
8
7
LA I
6
5
4
SRI
CK
3
2
6-Jul
16-Jul
26-Jul
5-A ug
D ate
15-A ug
25-A ug
Root Oxygenation Ability with SRI
vs. Conventionally-Grown Rice
Research done at Nanjing Agricultural University,
Wuxianggeng 9 variety (Wang et al. 2002)
Oxygenation ability of α-NA
(ug/h.gDW)
500
W
S
400
300
200
100
0
N -n
n-2
Heading
Development stage
M aturity
Plant Physical Structure and
Light Intensity Distribution
at Heading Stage
(Tao et al., CNRRI, 2002)
300
CK
Organ dry weight(g/hill)
SRI
250
47.9%
34.7%
Ye llow
le af and
she ath
Panicle
200
Le af
150
100
She ath
50
Ste m
0
Stage IH
H
FH MR W R YRIH
H
FH MR WR YR
Non-Flooding Rice Farming Technology in Irrigated Paddy Field,
Dr. Tao Longxing, China National Rice Research Institute, 2004
Roots of a single rice plant (MTU 1071)
grown at Agricultural Research Station
Maruteru, AP, India, 2003 season
Two rice plants in Cuba: same variety (VN 2084) and same
age (52 days); 42 tillers on SRI plant vs. 5 tillers on the other
ENDOPHYTIC AZOSPIRILLUM POPULATIONS, TILLERING AND
RICE YIELDS ASSOCIATED WITH DIFFERENT CULTIVATION
PRACTICES AND NUTRIENT AMENDMENTS
Results of replicated trials at the Centre for Diffusion of Agricultural Intensification,
Beforona, Madagascar, 2000 (Raobelison, 2000)
Azospirillum in the
CLAY SOIL
Traditional cultivation,
no amendments
SRI cultivation, with
no amendments
SRI cultivation, with
NPK amendments
SRI cultivation,
with compost
Rhizosphere
(103/ml)
Roots
Tillers/
Yield
(10 /mg)
plant
(t/ha)
25
65
17
1.8
25
1,100
45
6.1
25
450
68
9.0
25
1,400
78
10.5
25
75
32
2.1
25
2,000
47
6.6
3
LOAM SOIL
SRI cultivation,
with no amendments
SRI cultivation,
with compost
Rice grain yield response to N
uptake
SRI R 2=
14000
2
Conv 0.6159
=
Gr 12000
R
0.3144
ai 10000
Grain yield SRI
n
(kg/ha)
yi 8000
Grain yield Conv
el 6000
(kg/ha)
d
4000
Poly.:Grain yield
(k
SRI (kg/ha)
2000
g/
Poly.: Grain yield
0
ha
Conv. (kg/ha)
)
0
100
200
N uptake (kg/ha)
Figure 8: Linear regression relationship between N uptake
and grain yield for SRI and conventional methods,
using QUEFTS modeling methodology (Barison, 2002)
Results are from on-farm comparisons (N = 108)
Madagascar -- SRI field at Ambatovy, 2003
Sri Lanka – SRI field, 2002, with yield of 13 t ha-1
Cuba -- CPA Camilo Cienfuegos cooperative -- 14 t ha-1
China -- SRI rice field, hybrid variety, Yunnan, 2004 – 18 t ha-1
The System of Rice Intensification
• Was evolved in Madagascar over 20 yrs
by Fr. Henri de Laulanié, S.J. – working
with farmers, observing, experimenting,
also having some luck in 1983-84 season
• SRI is now spreading around the world
with positive results in 21+ countries:
Bangladesh, Benin, Cambodia, China, Cuba, Gambia,
Guinea, India, Indonesia, Laos, Madagascar, Myanmar,
Mozambique, Nepal, Peru, Philippines, Senegal, Sierra
Leone, Sri Lanka, Thailand, and Vietnam; more to come
• Association Tefy Saina was set up in 1990
to promote SRI; CIIFAD partnership 1994
Fr. de Laulanié not long before he died in 1995
Sebastien Rafaralahy and Justin Rabenandrasana,
president and secretary of Association Tefy Saina
SRI Practices Should Always
be Varied to Suit Conditions
The basic practices -- starting points -- are:
• Transplant young seedlings ( < 15 days ) –
although direct-seeding is becoming an option
• Wide spacing – single plants, in square pattern
• Soil aeration – thru water management and
weeding, so aerobic conditions prevail in soil
• Organic matter added to enhance the soil –
fertilizer not needed though it raises SRI yield
Weed control with ‘rotating hoe’ is recommended
Farmer innovation is an important part of SRI
Roller-marker devised by Lakshmana Reddy, East Godavari,
AP, India, to mark a square pattern on field and save time
in transplanting operations; his yield in 2003-04 season
was 16.2 t/ha paddy rice (dry weight)
Seeder developed by Luis Romero, Cuba, for planting
pregerminated seed, sowing 40x40 cm (too wide)
4-row weeder designed
by Gopal Swaminathan,
Tamil Nadu, India
Motorized
weeder
developed by
S. Ariyaratna,
Sri Lanka
SRI is controversial in some circles
• “Niche innovation” (Dobermann, Agric. Systems, 2004)
• “Voodoo science” (Cassman and Sinclair, ACSSA, 2004)
• “…[SRI] has no major role in improving rice production
generally” (Sheehy et al., Field Crops Research (2004)
• “Discussion of SRI is unfortunate because it implies SRI
merits serious consideration. SRI does not deserve such
consideration…” (Sinclair, Rice Today, 2004)
However, these critiques are not based on any extended or
empirical work with SRI, which is unfortunate
Best refutation is the empirical results that can be reported
from many different countries (purpose of this panel)
SRI creates new logic for rice production: Less gives more
LESS CAN PRODUCE MORE
by utilizing biological potentials & processes
• Smaller, younger seedlings become
larger, more productive mature plants
• Fewer plants per hill and per m2 will give
higher yield if used with other SRI practices
• Half as much water produces more rice
because aerobic soil conditions are better
• Greater output is possible with use of
fewer or even no external/chemical input
when soil communities are unimpaired
– living soil is the key to SRI performance
What Are the Negatives?
• Labor requirements initially are increased
but with experience, SRI can become:
– labor-neutral (GTZ evaluation in Cambodia) or
– even labor-saving (CAU evaluation in China)
• Water control is necessary for best results,
but can be achieved through investment/orgzn
• Farmer learning = benefit as much as cost
• Disadoption? – only reported in Madagascar
• Nematodes? – problem in Thailand and Laos
No claim that SRI will be successful everywhere
CAU Evaluation of SRI in Xinsheng Village,
Dongxi Township, Jianyang County,
Sichuan Province, August 2004
•
•
•
•
•
2003 – 7 farmers used SRI (SAAS)
2004 – 398 farmers used SRI (65%)
2003 – SRI plot size average 0.07 mu
2004 – SRI plot size average 0.99 mu
86.6% of SRI farmers (65/75) said they
would expand their SRI area next year
or keep their whole rice area under SRI
Xinsheng Village, Dongxi Township
Standard
Methods
RICE YIELD (kg mu-1)
2002
2003*
2004
403.73
297.88
375.77
SRI
-439.87
507.16
----------------------------------------------------------SRI Increase (%)
+46.6%
+34.8%
*Drought year
Water saving/mu -- calculated at 43.2%
Farmers said labor-saving greatest benefit
Advantages of SRI – beyond yield
• Cost reduction – increased profitability
• Lower capital requirements – accessible for
poorer households – food security
• Resistence to biotic stresses – less pest and
disease problems, no agrochemicals
• Resistance to abiotic stresses – greater drought,
cold, storm and salinity tolerance, no lodging
• Environmental benefits – less chemicals, lower
water demand, reduced GHGs?
• Biodiversity conservation – tradl. varieties
• Grain quality – higher milling outturn, nutrients?
Two rice fields in Sri Lanka -- same variety,
same irrigation system, and same drought :
conventional methods (left), SRI (right)
MEASURED DIFFERENCES IN GRAIN QUALITY
Characteristic
SRI (3 spacings) Conventional
Diff.
Chalky kernels
(%)
23.62 - 32.47
39.89 - 41.07
- 30.7
General
chalkiness (%)
1.02 - 4.04
6.74 - 7.17
- 65.7
Milled rice
outturn (%)
53.58 - 54.41
41.54 - 51.46
+ 16.1
Head milled
rice (%)
41.81 - 50.84
38.87 - 39.99
+ 17.5
Paper by Prof. Ma Jun, Sichuan Agricultural University,
presented at 10th conference on Theory and Practice for
High-Quality, High-Yielding Rice in China, Haerbin, 8/2004
SRI STILL RAISES MORE
QUESTIONS THAN WE HAVE
ANSWERS FOR
• There are many researchable issues
to be taken up by scientists, in
association with farmers and with
extension personnel
• However, enough is known now to
pursue a two-pronged strategy
with (a) research and (b) practice
proceeding in parallel
THANK YOU
Email: [email protected]
or [email protected]
Web page:
http://ciifad.cornell.edu/sri/
Effects of SRI vs. Conventional Practices
Comparing Varietal and Soil Differences
12
10
8
Local-Clay
Local-Loam
HYV -Sand
Local-Sand
6
4
All SRI
3/4 SRI
2/4 SRI
1/4 SRI
0
Conv.
Practice
2