1.
Agroecological Management of Soil Systems for
Food, Water, Climate Resilience, and Biodiversity
Norman Uphoff
Cornell University
Presentation for Knowledge Dialogue on the Occasion of
World Soil Day – United Nations, NYC – 6 December 2019
Sponsored by IUCN, WCS, and the Government of France

2.
AGROECOLOGY is the science and practice of agriculture that
relies primarily on mobilizing processes and potentials which exist
within our agroecosystems – in their soil systems, in their crop
plants and animals, and in their soil biota.
By optimizing the management of soil, water, and nutrients to support crops
and animals, and by capitalizing on existing genetic potentials within
agroecosystems, food production can be increased with:
 Less need for water, lower costs, and more income,
 More resilience to the stresses of climate change,
 Enhancement of biodiversity, esp. below-ground,
Further, reduced or no reliance on chemical fertilizers &
agrochemicals improves water quality, soil health, and human health.

3.
Agroecological management of crops, soil, water, and
nutrients is exemplified in the discussion today by the
System of Rice Intensification, known widely now as SRI.
This methodology was developed in Madagascar in the
1970s-80s by a French priest, Fr. Henri de Laulaniè, S.J.
SRI ideas and methods for irrigated rice have been adapted to
other crops: wheat, millet, sugarcane, teff, mustard, etc.
SWI in Bihar STI in Ethiopia

4.
SRI was initially ‘controversial’ because it proceeds in a
different direction from ‘Green Revolution’ technology.
No longer much controversy: >1,000 articles in the literature
(http://sri.cals.cornell.edu/research/JournalArticles.html)
 Acceptance from FAO, World Bank, IFAD, IICA and other agencies

5.
1st validation outside of Madagascar was in China (1999) and Indonesia (1999-
2000)  effects have now been demonstrated over 60 countries.
Validation = more productive, robust phenotypes from a given genotype.
SPREAD OF SRI METHODS

6.
Here is a rice plant grown according to SRI principles in Indonesia, with
223 tillers and huge root system grown from a single seed.
1. Reduce plant population, 80-90%, by transplanting
very young seedlings, singly, and in square pattern.
2. Maintain mostly aerobic soil conditions, reducing water
issues by 25-50%, so roots do not suffocate.
3. Enhance organic matter in the soil to support the
abundance and activity of beneficial soil biota.
4. Active soil aeration with mechanical weeder that breaks
up surface soil as it removes weeds.
Such management of crop, soil, water and OM will
produce better phenotypes from a given variety. SRI is
regarded more as a menu than as a recipe (although
the practices can be synergistic).
EFFECTS OF AGROECOLOGICAL MANAGEMENT

7.
These methods improve the structure and functioning of the
SOIL SYSTEM and promote MORE LIFE IN THE SOIL, from
beneficial microbes to earthworms. Wider PLANT SPACING is
also important, for more growth of roots and canopy.
With more soil organic matter + aerobic soil conditions 
 Better aggregation of the soil (fungi),
 More soil porosity (circulation of air, water),
 Easier penetration and better growth of roots,
 More C (energy), O2 and H2O for the growth of
plant roots and aerobic soil organism.

8.
Studies of the rhizospheres of SRI plants at Tamil Nadu
Agricultural University and ICRISAT in India, and Bogor
Agricultural University (IPB) in Indonesia
I. Anas et al., A review of studies on SRI effects on beneficial soil organisms in rice
soil rhizospheres, Paddy and Water Environment, 9: 53-64 (2011)
RHIZOSPHERE EFFECTS
Average increase of 76%

9.
2004-2010 data from Sichuan Provincial Dept. of Agriculture
Note: climate resilience in the drought years 2006 and 2010  10% yield advantage
Also: SRI yields were achieved with about 25% less water per hectare
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
Conv. 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%
Grain increment (tons） 1,547 12,971 103,320 197,008 352,705 450,653 546,436 1,664,640
Grain price (RMB /kg) 1.44 1.44 1.44 1.5 1.8 1.84 1.95 1.63
Added net income due to
SRI methods (million RMB)
1.28 11.64 106.51 205.10 450.85 571.69 704.27
2,051,340
( $300 m )
INCREASED RICE PRODUCTION IN CHINA WITH SRI

10.
CUBA: Farmer Luis Romero showing the effects of SRI management on
the growth of rice plant roots and tillers -- 5 tillers vs. 42 tillers
These plants are the same age and
same variety, but very different in their
expression of genetic potential

11.
LIBERIA: Edward Sohn showing
rice plants of the same variety
grown in adjacent fields in Grand
Gedeh county --
SRI plant on right.

12.
MIDDLE EAST: Pictures sent to Cornell from the national rice
research stations in Iran (Haraz) and Iraq (Al-Mishkab) to show
how their use of SRI methods was inducing the
growth of larger plants with healthier root systems

13.
IRAQ: Test plots at Al-Mishkhab research station near Najaf,
comparing varietal responses to SRI management, 2007
SRI practices (young seedlings, wider spacing, compost, etc.) were used in the
left-hand plots of these paired plots, each with the same rice variety

14.
is a major benefit with agroecological soil management
 ‘Life in the soil’ enhances water infiltration, retention, and availability
 Agroecological practices rely more on ‘green water’ than ‘blue water’
 Results of a meta-analysis of 29 studies published from 2006 to 2013
reporting on 251 comparison trials in 8 countries:
SRI management: 12.03 million liters ha-1 with higher grain yield
vs. standard management: 15.33 million liters ha-1
- SRI  22% reduction in total water use (irrig + rainfall) per ha, and
SRI  35% average reduction in irrigation water use per ha
- 52% higher total water use efficiency -- 0.60 vs. 0.39 g rice per liter
- 78% greater irrigation WUE -- 1.23 vs. 0.69 grams of rice per liter
P. Jagannath et al., Taiwan Water Conservancy, 61:4 (2013)
WATER SAVING

15.
Note: Reducing or stopping continuous flooding
of rice paddies not only saves water and increases yield  it
makes working conditions for women easier and healthier
Less disease
Less discomfort
and disability –
80-90% fewer
seedlings
Save time
Less drudgery –
weeder is very
good for women

16.
GREATER WATER USE EFFICIENCY IN SRI PLANTS
 More productive SRI rice plants give greater water-
use efficiency as measured by the ratio of
photosynthesis-to-transpiration.
 For each millimol of water lost by transpiration,
3.6 μmols of CO2 were fixed by SRI plants vs.
1.6 μmols of CO2 were fixed by RMP plants.
 This becomes more important as climate change
makes water a scarcer resource.
 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, 77-98 (2010)

17.
can be seen from rice fields in Sri Lanka planted with the
same variety and served by the same irrigation system, which
had dried up 3 weeks before picture -- SRI on right
DROUGHT RESILIENCE

18.
IWMI team evaluated two districts of Sri Lanka in 2004, comparing the rice crops of 60
farmers who used SRI methods and of 60 matched farmers using standard methods.
The 2003/04 main season had experienced 75 days of severe drought.
 80% of the tillers on SRI-grown rice plants formed panicles (grain), while only 70% of
the rice plants grown with usual crop management methods did so.
 With SRI, the number of panicle-bearing tillers per m2 was 30% higher in this
drought-stressed season even tho conventional fields had 10x more plants/m2.
 Number of grains/panicle on SRI plants was 115.6 vs. 87.4 on other plants.
 Harvested yield was 33% more: 6.37 tons/ha vs. 4.78 tons/ha (33% more)
 Under drought conditions, the SRI-managed plants has greater translocation of
photosynthates into the grains.
EVIDENCE OF DROUGHT RESILIENCE
The practice and effects of the System of Rice Intensification (SRI) in Sri Lanka, R.
Namara et al., Quarterly Journal of International Agriculture (2008)

19.
CLIMATE-CHANGE RESILIENCE AND RESISTANCE
Less effect of drought and water shortages
Resilience to storm damage (lodging from wind & rain)
More tolerance of cold temperatures
Lower levels of pests and diseases
Also, greenhouse gas emissions from irrigated rice fields are
lower by 20-30% per hectare with SRI; even more reduction
per kg of rice produced. Reducing GHG emissions helps to
slow and mitigate climate change.

20.
VIETNAM: A farmer in Dông Trù,
standing in front of her SRI field on
left, and conventionally-grown rice
field on the right.
A tropical storm had passed over
her village a few days previously.
She holds up rice plants from their
respective fields where they are
grown.

21.
Improved rice
variety planted
(Ciherang) with
fertilizer use and
agrochemical
protection
= little yield
PEST RESISTANCE PLUS WEATHER
RESILIENCE
Adjacent paddy fields in East Java, Indonesia, after being hit by
brown planthopper (BPH) attack and by tropical storm in 2011
Traditional
aromatic rice
variety planted
(Sinantur) with
organic SRI
management =
8 t/ha yield

22.
HIGHER NUTRIENT CONTENT OF GRAIN
Nutrient value of rice is expected to decline with climate change *
Three studies by Indian researchers (IARI and ICAR) have shown higher
micro-nutrient content of rice grains grown under SRI **
* Climate change will make rice less nutritious: When scientists exposed the crop to
higher levels of CO2, vitamin levels fell, The Guardian, 23 May (2018)
** Micronutrient enrichment mediated by plant-microbe interactions and rice cultivation
practices, Journal of Plant Nutrition, 39: 1216-1232 (2016)

23.
SRI management also supports biodiversity conservation
 MADAGASCAR: 1st validation of SRI was around Ranomafana National Park to give
small farmers a better alternative to ‘slash-and-burn’ rice cultivation  SRI raised
farmers’ average paddy yields from 2 t/ha to 8 t/ha.
 ZAMBIA: Through its COMACO program, WCS is currently using SRI to reduce
pressures on Luangwa National Park, rich in wildlife biodiversity
 CAMBODIA: WCS is using SRI methods in program for protection of giant ibis.
 INDIA: WWF/ICRISAT project from 2005 to 2010 was a major supporter and
promoter of SRI to reduce pressures for constructing mega-dams; also a
UNDP/GEF project in Maharashtra state is promoting SRI methods to protect
endangered mangrove ecosystems, in part by reducing chemical runoff.
 INDONESIA: small projects have introduced SRI to farmers to help protect the
habitats of orangutans and Java rhinoceros (GEF)
BIODIVERSITY CONSERVATION

24.
ZAMBIA: Pictures from WCS introduction of SRI around
Luangwa National Park to protect wildlife there

25.
SRI CONSERVES RICE BIODIVERSITY
 Traditional varieties perform very well with SRI practices, better than with
input-intensive ‘modern’ management; in India before GR, the number
of local varieties was 82,000; now this number about 1,500.
 Traditional varieties are more profitable under SRI management due to
lower production costs and higher market prices that reflect consumer
preferences; the economics of SRI make many local varieties
economically competitive with HYVs and hybrids.
Yields from ‘unimproved’ varieties with SRI are generally about 4-5
t/ha; yields from these varieties can be as high as 10-12 t/ha.
 Also, soil biodiversity is better protected because SRI reduces or
eliminates the use of agrochemicals and chemical fertilizer; this benefits
the health and abundance of the soil biota.

26.
is important in part because of the effects that the
plant microbiome has on plants’ growth and health
 New area for research - Already well-established that soil microbes in the
rhizosphere fix nitrogen (N), solubilize phosphorus (P), mineralize and make
available other nutrients, produce phytohormones, protect against pathogens,
and induce systemic resistance to pests and diseases.
 Microbes living within plants as endophytes such as rhizobia and fungi
(Trichoderma) can accelerate growth, increase plants’ photosynthesis, induce
resistance to stresses both biotic (pests) and abiotic (climate).
 Evidence is growing that endophytes living within plants can modify their host
plants’ gene expression in beneficial ways. Stay tuned….
SOIL BIODIVERSITY

27.
Thanks… and come visit SRI-Rice
 Questions or suggestions?
Contact: Norman Uphoff ntu1@cornell.edu
 For more information on SRI:
SRI International Network and Service Center (SRI-Rice),
B75 Mann Library, Cornell University sririce@cornell.edu
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