1611 - Agroecological Strategies for Regenerative, Climate-Smart Agriculture with examples from CA...
-
Upload
sri-rice-international-programs-cals-cornell-university -
Category
Environment
-
view
726 -
download
0
Transcript of 1611 - Agroecological Strategies for Regenerative, Climate-Smart Agriculture with examples from CA...
Agroecological Strategies forRegenerative, Climate-Smart
Agriculture with examples from CA and SRI
Norman Uphoff, SRI-Rice Center, Cornell University, USA,and Amir Kassam, CA-CoP, Reading University, UK
Presentation prepared for BBL seminar atWorld Bank, Washington, DC, Sept. 29, 2016
Question: How for this 21st century can we learn to PRODUCE MORE
WITH LESS?This paradoxical relationship will be crucial for us to achieve sustainable agricultural development because in the long run,
it will not suffice for us just to be making efficiency gains when we are producing more from more.
The amount of arable LAND per capita is declining, and also soil quality is diminishing in many parts of the world.
WATER supply for agriculture becomes less (and less reliable) at same time that costs of ENERGY and INPUT prices increase.
We need to protect and to maintain the quality of our NATURAL RESOURCES (soil, water, air), and we should
ensure broad access to APPROPRIATE TECHNOLOGY to be able to reduce hunger and poverty in the world.
After short introduction, this presentation reviews:1. Limitations of the current paradigm which
is guiding our agricultural R&D, and then2. Prospective benefits of agroecological approaches for regenerative
agriculture, e.g., Conservation Agriculture (CA) and SRI.
In this presentation, there is no intention of:1. Bashing the ‘Green Revolution’ – the GR has
been productive and was the best we knew how to do, or
2. Making an advocacy presentation for CA or SRI. Their spread, results and impacts,
briefly reviewed, ‘speak for themselves.’ This will be a science-based, science-oriented
presentation – but with visual punch.
WHAT IS AGROECOLOGY?A family of complementary management strategies: * Integrated Pest management (IPM)
was the first agro- ecological methodology to gain widespread acceptance* Conservation Agriculture and SRI, our focus, are now spreading
* Agroforestry and aquaculture, esp. when part of farming systems, and also holistic land/range management (cf. Alan Savory).
* Agroecology is based not on specific inputs as was the Green Revolution, but rather on synergistic management
of ensembles of natural resources, incl. genetic resources.
* Agroecology capitalizes for agricultural purposes upon interactions and genetic potentials of crops and animals, as well as on interactions and potentials of soil systems and the other larger-scale ecosystems in which they live.
5
The Four ‘Pillars’ of Agroecology:• Maintaining and augmenting SOIL HEALTH, • Protecting and nurturing of BIODIVERSITY, both above-ground and below-ground,
• Promoting the growth and functioning of ROOT SYSTEMS, and
• Appreciating, benefiting from, and enhancing the services of the SOIL BIOTA.
• All of these elements -- which are actually just good agronomy -- were mostly ignored by the science and the practice of the Green Revolution.
6
Conservation Agriculture (CA)• Started as ‘no-till cultivation.’ However, over the last 25 years it has evolved to encompass these three ‘pillars’:
• Minimum or no mechanical soil disturbance – with crop establishment by direct-seeding or transplanting, seeking to conserve soil structure, soil carbon, soil nutrients, and biota.
• Continuous soil cover with organic mulch, crop stubbles and/or residues to minimize erosion; to conserve soil water, carbon and nutrients; to moderate soil temperatures; and to enhance nutrient availability for the soil and its biota.
• Diversified cropping to support biodiversity above and below ground; greater diversity of root exudation supports a more diverse and beneficial soil biota; reduce pest pressure.
7
• CA is an integrated system of soil, plant, water, and nutrient management intended to create more optimal growing environments for crops and to enable them to express their genetic potentials more fully. CA practices:
• Maximize soil systems’ absorption/retention of water; achieve more capture and availability of ‘green water.’
• Create favourable conditions for root growth and health• Promote soil fertility by enhancing the life in the soil; optimizing supply of water to favor populations of aerobes with good supply of micronutrients and air.
• Maintain soil temperature within favorable ranges.
8
Worldwide adoption of Conservation Agriculture
Connference on Conservation Agriculture for Smallholders in Asia and Africa. 7-11 December, Mymensigh University, Bangldesh
100
Dustbowl
1930 20001950
US
Soil
Cons
erva
tion
Serv
ice
cons
erva
tion
tilla
ge
dust
bow
lSi
beria
/USS
R
Faul
kner
(US)
– F
ukuo
ka (J
apan
)
com
mer
cial
no-
till/
US
first
no-
till d
emon
stra
tion
in B
razi
l
Old
rieve
/Zim
babw
e
adop
tion
Braz
ilpl
antio
dire
to n
a pa
lha
exp
erim
ents
in C
hina
, Ind
ogan
getic
Pla
ins
New
boo
st: C
anad
a,
Aust
ralia
, Kaz
akhs
tan,
Russ
ia, C
hina
, Fin
land
...;
Afric
a
Arge
ntina
, Par
agua
y;
1980 1990
Firs
t no-
till i
n th
e U
S
IITA
no-ti
ll re
sear
ch
50
Mill
. ha
Spread/Adoption/Adaptation of CA from 1970s through 2013 --
since 2008/09, CA area has been increasing annually by ~10 M ha
1970 2010
157 mill ha
first
no-
till f
arm
ers i
n U
SA
Firs
t WCC
A in
Mad
rid
9
System of Rice Intensification (SRI)• Started in Madagascar as a low-external-input cropping system for small-scale, resource-limited farmers growing irrigated rice. Now the original SRI ideas are broadly extended:
• To upland rainfed rice cultivation,• To larger-scale production, through mechanization, • To improving many other crops – wheat, finger millet,
sugar cane, mustard, tef, legumes, vegetables and herbs … • These various innovations are grouped under the rubric of
the System of Crop Intensification. SCI results similar to SRI have been seen in WB project in Bihar state of India:
11
• The principles of SRI/SCI are more important than are any specific practices. The SRI/SCI principles can be summarized as:
• Undertake early and healthy plant establishment, e.g. use young seedlings. But direct-seeding is becoming an appropriate SRI practice in many places and for many crops because it can save on labor.
• Minimize the competition among plants with optimally wider spacing for greater canopy and root growth, leading to more light interception and to increased root system growth.
• Build up fertile soils that are well-endowed with organic matter and have large, diverse communities of beneficial soil biota.
• Manage water so as to avoid extremes of flooding and water stress, e.g., AWD, support aerobic soil organisms and larger root systems.
Spread/Adoption/Adaptation of SRI since 2000More than 10 million farmers in >50 countries were benefiting from the use of SRI methods and ideas by the end of 2015 on
~4.0 million hectares -- SRI yield increases average 1.66 t ha-1 with less water and lower cost
SRI-Rice (2014)
13
Common Benefits of CA and SRI/SCI• Production increases: 20-50%, can be 100% or more• Increased factor productivity: greater output per unit of land, labor, capital,
seeds, and water• Lower water requirements, esp. for irrigated rice under SRI management• Cost reductions: less need for fertilizer, agrochemical inputs, fuel, etc.• Greater profitability: more output with lower cost higher farm incomes• Soil health & functioning: enhanced cycling of water, carbon, and nutrients• Ecosystem services: better water quality, C sequestration, flood control, etc. • Adaptability and resilience in response to climate change: resistance to
drought, storm damage (lodging), extreme temperatures, pests and diseases• Climate-change mitigation: reductions in GHG emissions (SRI by 20-70%)• Crop-cycle shortening: SRI rice up to 15 days; less exposure to climate hazards• Higher milling outturn per bushel/bag of SRI paddy rice = a 10-15% ‘bonus’• Biodiversity conservation for soil biota and crop varieties
14
Costs and Constraints of CA and SRI/SCI• Time: Some learning curve is involved. Both CA and SRI take some time and
experimentation for farmers to gain skill and confidence in the system, and to make good adaptations for optimizing their resources under local conditions.
• Soil quality and biological endowments: Effects of both CA and SRI are less on soils that have been degraded by conventional management. Agroecological methods can restore soil system health and fertility, but repairing soil structure and functioning is needed to revive the abundance and diversity of soil biota.
• Appropriate equipment: Both CA and SRI are more acceptable and profitable with implements that reduce labor time/cost and enhance effectiveness.
• CA usually needs ability to absorb costs for first year or few years after conversion for rehabilitating depressed soil systems from the effects of previous practices. SRI usually gives higher yield and profitability from the first season.
• SRI requires an ability to invest more time and labor initially while learning new techniques. Where rice production is already labor-intensive, as in most of Asia, SRI is usually found to be labor-neutral or even labor-saving from outset.
China National Rice Research Institute conducted trials using two super-hybrid rice varieties in 2004 and 2005, with the aim of breaking the ‘yield plateau’ limiting hybrids
Standard Rice Mgmt vs.
• 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
Yields (kg ha-1) with ‘new rice management’ vs. standard rice management (SRM)
atthree different levels of plant density ha-1
0100020003000400050006000700080009000
10000
150,000 180,000 210,000
NRMSRM
Plant population per hectareSRI practices yield more productive phenotypes – for years, Chinese farmers have been WASTING seeds, water, and N fertilizer when they can get
higher output with fewer inputs
Current paradigm for agricultural R&D relies on genetic improvements, on increased use of
agrochemical inputs for soil fertility and crop protection, and on more irrigation (water)
** Soil science research for the past ~ 50 years:60-70% soil chemistry
20-30% soil physics< 10% soil biology [now more]
** Crop science research for the past ~ 50 years:> 90-95% has focused on shoots above-ground
< 5-10% has focused on roots below-groundGross underinvestment in roots and soil biology
Productivity of any technology is a function of factor proportions (their relative productivity and
economic returns) and their suitability for (changing) conditions (Hayami & Ruttan, 1985)
Growing scarcity of water is a game-changer,
underscoring the importance of ROOTSClimate variability raises risks of
monocultureClimate change overall is modifying the
merits and productivity of existing technologies
Any paradigm is bound to encounter DIMINISHING RETURNS at some point
1960 1970 1980 1990 2000 2010 20200
50010001500200025003000
0
100
200
300
400
World Grain Production, 1961-2015 Total and Per
CapitaW
orld
Gra
in P
rodu
ctio
n (m
illio
n to
ns)
Gra
in P
rodu
ctio
n pe
r ca
pita
(kg
)
Starting in the early 2000s, I began tracking this time series,
put together with data from Worldwatch Institute’s data bank
Decelerating Pace of the Green Revolution
20
(Brisson et al. 2010)
Stagnating Yields with Tillage-Based Systems since 1990sA regression analysis of wheat yields throughout various European
countries
As both input use and input costs are going up, diminishing returns are setting in,
Diminishing returns to fertilizer inputs
as experienced in ChinaAt 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., 2010) -- and it is still declining
S.B. Peng et al., “Improving N fertilization in rice… “ Agronomy for Sustainable Development, 30 (2010),
649-656.
This has adverse environmental consequences as nitrate (NO3) levels in China’s groundwater supplies have been
rising rapidly due to the overuse of N fertilizer – based on a mistaken belief that
if some is good, more is better
Already >10 years ago, in many parts of China, the level of NO3 in groundwater was
>300 ppm; in the US, the EPA allowance is 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
How to address these problems to which the current paradigm has contributed?
Need to find ways to grow more productive and resilient crops with less or maybe no
dependence on agrochemical inputs. How to get better phenotypes from
genotypes,whether ‘improved’ and ‘unimproved’?
Making genetic improvements should and will continue -- but as one of our approaches, not
as the only approach, or always the best approach.
We eat and live on phenotypes, not genotypes.
Enhanced phenotypic
expression of a crop’s genetic
potential is seen in this rice plant from East Java,
Indonesia
This plant (Ciherang cv.) with 223 tillers and a
massive root system was grown from a single seed
using SRI methods--
Panda’an, E. Java, 2009
See better phenotype from same genotype: these plants grown in Cuba are same variety (VN 2084)
and same age (52 DAS); SRI plant on right
Comparison trials in Iraq: Pairs of same-variety trials at Al-Mishkhab Rice Research Station, Najaf; trials with SRI
management are on the left
SRI
0
50
100
150
200
250
300
IH H FH MR WR YRStage
Org
an d
ry w
eigh
t(g/
hill)
IH H FH MR WR YR
CK Yellow leafand sheath
Panicle
Leaf
Sheath
Stem
47.9% 34.7%
Data reported by Dr. Tao Longxing, China National Rice Research Institute, at International SRI rice conference in Sanya, 2004
Differential growth of plant organs seen in same rice variety, over time
Crop management can have significant plant phenotypical impacts
that affect:
↑ Crop productivity – yield, water requirements↑ Grain quality – micronutrient uptake; milling
quality, e.g., chalkiness, breakage of grains↑ Resistance to stresses – drought, lodging,
cold temperatures, pests and diseasesInteractive effects with soil microbes:↑ Soil structure and soil system functioning↓ GHG emissions → ↑ methanotrophs (CH4)
↑ Symbiotic endophytes – which affect plants’ expression of their genetic potential
(THOMAS, 2004)
CA vs. conventional-till sugar beets in Switzerland – see water infiltration just after
a thunderstorm
CA Ploughed
This is same beet crop approaching maturity
See differences in size and conformation of beets: CA on left;
conventional tillage on right
CA maize in Timor Leste -- impact of El Niño, 2016
At Darasula research station - Baucau At Cribas - Manatuto
At Abat Oan - Natarborai At Limialeten - Ermera
FAO Project
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 in Sri Lanka: Rice fields 3 weeks after irrigation issues were stopped because of drought --
conventionally-grown field on left, and SRI field on right have same variety, same soil, same
climate
Year 2004
2005
2006
2007
2008 2009 201
0 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 9,55
5 9,252Non-SRI yield (kg/ha)
7,740
7,650
7,005
7,395
7,575 7,710 7,74
0 7,545SRI 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
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 for SRI paddy yield and profitability is with Sichuan provincial average # In drought years, SRI yields were relatively higher than with conventional methods Source: Data are from the Sichuan Provincial Department of Agriculture.
Evidence of SRI drought-resistance from Sichuan, China
Evidence on water saving and water productivity from a meta-analysis of 29
published studies (2006-2013), withresults 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% 11% more yield: SRI 5.9 tons ha-1 vs. 5.1 tons ha-1 -- usually SRI yield increase is much more 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)
Evidence at the molecular level that SRI phenotypes have higher within-plant water-use
efficiency as measured by the ratio of photosynthesis : transpiration
For each 1 millimol of water lost by transpiration:in SRI plants, 3.6 micromols of CO2 are fixed vs.
in RMP plants, 1.6 micromols of CO2 are fixedThis becomes more important with climate
change and as water becomes a scarcer factor of production“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. AntonyExperimental Agriculture, 46(1), 77-98 (2010)
Storm resistancein Vietnam:
adjacent fields after being hit by a tropical storm
in Dông Trù village,Hanoi province
On left: SRI fieldand rice plant; on
right, conventional field and plant
Same variety was grown in both fields -- on right, there was
serious lodging;on left, no lodging
From a GIZ/IFAD publication (Dill et al., 2013): adjacent paddy fields in Trà Vinh province in the
Mekong Delta, Vietnam after a tropical storm had passed over -- SRI plot is in back-right
Storm resistance seen in Kenya
--rice fields in
Mwea irrigation scheme
Conventional field on left, and SRI field above, after a severe storm had
passed over the Mwea scheme
Photos from Dr. B. Mati, JKUAT
Evidence of disease and pest resistance in Vietnam: Averaged data collected by
National IPM Program from on-farm trials in 8 provinces, 2005-06
Spring season Summer seasonSRI
plotsFarmerplots
Differ-ence
SRIplots
FarmerPlots
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 in East Java, Indonesia: both fields were hit by
brown planthopper (BPH) and tropical storm; on left, field grown with standard practices; on right,
organic SRI field
Modern improved variety (Ciherang) – no yield
Traditional
aromatic variety
(Sintanur)
- 8 t/ha
Resistance to cold temperatures in India: Yield and meteorological data from
ANGRAU, A.P.
Period Mean max. temp. 0C
Mean min.
temp. 0C
No. of sunshine hrs
1 – 15 Nov 27.7 19.2 4.916–30 Nov 29.6 17.9 7.5 1 – 15 Dec 29.1 14.6 8.616–31 Dec 28.1 12.2# 8.6# Sudden drop in minimum temp. for 5 days, 16-21 December
(9.2-9.9o C )
Season Normal (t/ha) SRI (t/ha)
Rabi (winter) 2005-06
2.25 3.47
Kharif (monsoon) 2006
0.21* 4.16* Low yield was due to cold injury (see below)
Measured Differences in Grain Quality
Conv. Methods SRI Methods Characteristic (3 spacings) (3 spacings) DifferenceChalky
kernels (%)
39.89 – 41.07
23.62 – 32.47
-30.7%
General chalkiness (%)
6.74 – 7.17 1.02 – 4.04 -65.7%
Milled rice outturn (%)
41.54 – 51.46
53.58 – 54.41
+16.1%
Head milled rice (%)
38.87 – 39.99
41.81 – 50.84
+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,” Harbin, 8/2004
Agroecological crop management has similar favorable phenotypical effects in OTHER CROPS beyond rice – e.g., wheat, finger millet, sugarcane, maize, tef, mustard, legumes,
vegetables, spices (not just monocotyledons)
The System of Crop Intensification: Agroecological Innovations for Improving Agricultural Production, Food Security, and Resilience to Climate Change – monograph from SRI-Rice (2014), co-published
with CTA, Wageningen (2015) and NABARD, Mumbai (2016)
SWI wheat crop (left) in Bihar state of India, Chandrapura village, Khagarla district – wheat
fields are same age and same variety
GRAIN YIELD (t ha-1)
STRAW YIELD (t ha-1)
Economic
returns
Treatments
2011-12
Normal climate
2012-13
Climate stress
Yield
reduc-
tion
2011-12
Normal climate
2012-13
Climate
stress
Yield
reduc-
tion
Ave. for 2 years
(US$ ha-
1)
SRP (BMP)
6.08 4.75 22% 9.05 7.24 20% 1,020
FIRB 5.87 4.58 22% 8.81 6.96 21% 974MSRP-IR 6.08 4.17 31% 7.56 6.25 17% 886MSRP-SP
5.80 4.75 18% 11.19 7.16 36% 967
SWI 7.93 6.94 12% 12.53 11.09 12% 1,382LSD (P=0.05)
1.06 0.82 2.33 1.98
SRP = Standard recommended practices: seed drilled in 20 cm rows @ 100 kg ha-1; 6 full irrigations; fertilizer 150:60:60 kg NPK ha-1; 1 spraying with sulfosulfuron herbicide; FIRB = furrow-irrigated, raised-bed planting; MSRI = modified SRP with one SWI practice, either IR = SWI irrigation, or SP = SWI spacing; SWI = System of Wheat Intensification: 2 seeds/hill; 20x20 cm spacing, 5 shallow irrigations;; use of compost/vermicompost/biofertilizers; 3 soil-aerating mechanical weedings
Results from two years of System of Wheat Intensification (SWI) evaluation trials at Indian Agricultural Research Institute
station, New Delhi, 2011-13 --S. Dhar et al., Archives of Agronomy and Soil Science (2015), 994-
1006
Size and width of panicles and
rootsof finger millet with alternative
crop management
-- SFMI plants on left, and farmer
practice on right;Jharkhand state,
India
Sustainable Sugarcane Intensification (SSI) plants in
Maharashtra, India
SSI sugarcane in Cuba @ 10.5 months;
eventual yield estimated @ 150 t/ha
SSI Tillering per Germinated Bud vs. Conventional[slide from AgSRI Pvt. Ltd., Hyderabad, India, which promotes SSI in India and abroad – www.agsri.com/ ]
• Conventional planting – one-third of initial tillers usually perish
• SSI - most of the tillers form millable canes
Method No. planted
Germi-nation.
No. of germinants
Millable canes
Millable canes per
bud planted
Convenl. 75,000 60 % 45,000 80,000 1.0-1.8SSI 12,500 125, 000 10
Benefits of SSI, according to AgSri (www.agsri.com/)
1. Considerable reduction in cost of cultivation2. Reduction in seed material by as much as 95% if the
chipped canes are not wasted, but are crushed for sugar manufacture or for jaggery makingConventional planting = 8 tonnes/ha (8,000 kg/ha) SSI planting: weight of bud chip = 15 g eachTotal weight of 12,500 bud chips = < 200 kg/ha200 kg is ~ 2.5% of conventional seed cane required
Benefits of SSI (continued) 3. Water saving
Nursery = > 90% saving in the 1st month (nursery period)Main field – substantial water saving as water is used efficientlyInitial population in conventional method (80,000 buds) gives only
48,000 sprouts because of only 60% germination rateInitial population in SSI (12,500) = 1/4th of conventional amount;
robust root system, already formed, absorbs moisture readily4. Significant reduction in the use of labour during planting5. At least 20 % yield improvement if the SSI practices are
effectively followed, and usually get greater improvement6. Crop stands in the field for one month less time7. Additional income received from intercrops
Benefits of SSI (continued)8. Weed reduction due to intercropping9. Avoiding monocropping enhances HH food security -- also
addresses problems of biodiversity in cane production10. Soil health – abundance of microbial populations with
interecropping contributes to this11. Little need for gap-filling due to low on-farm mortality12. Very good and uniform tillering -- thick and tall canes have
increased weight of individual canes13. Higher sugar recovery rate -- 0.2 unit increase in sugar
recovery due to very uniform canes in evaluation by Ponni Sugars, Tamilnadu, India; SSI rate compared to conventional in cv. CO-86032 (3 samples each) was 0.27 units higher
System of Tef Intensification (STI)
methods in Ethiopia – more productive phenotypes from
available genotypes, both local and
improved -- yields up to 6+ t ha-
1
STI tef crop maturing with full heads of grain -- in 2014/15, 2.2 million Ethiopian farmers were using
direct-seeded TIRR methods (‘STI-lite’)
These beneficial effects from modified crop management practices are NOT LIMITED to small-scale, labor-intensive production systems
In Punjab province of Pakistan, both CA and SRI principles and practices are being integrated in what is called ‘paradoxical agriculture’ (PA). Why? More output is produced with fewer inputs = PA
** A 40-acre test plot gave a paddy yield of 12 t ha-1 with 70% less labor and a 70% reduction in water.
A. Sharif, “Technical adaptations for mechanized SRI[production to achieve water saving and increased profitability in Punjab, Pakistan,” Paddy and Water Environment, 9: 111-119 (2011).
Mechanized System of Crop Intensification (MSCI) leading to Conservative Regenerative
Paradoxical Agriculture (PA)
Rice crop on raised-beds – saves 70% water and other inputs
Webpage: FC.com/pedavereMail: [email protected]
PA (mechanized CA/SRI) on raised beds formed by machinery on laser-leveled fields
in the Punjab
Seedlings 10-days old are dropped into mechanically- punched holes, which are then
filled with water. The field is flooded only once, just after transplanting. Thereafter, furrow irrigation is used to reduce water
needs. Energy is saved by using siphons to move water.
Tractor-weeding of precision-planted raised beds actively aerates the soil, while
furrow irrigation economizes on water (tractor is radio-controlled)
Phenotypical differences seen in plant growth using
PA (CA/SRI) methods
PA wheat plantation on raised beds
PA wheat plantation on raised beds
PA carrots planted on raised beds
PA carrots planted on raised beds -- more uniform carrots get higher price
What underlies and undergirds all of this is the MOBILIZATION of the services and protection of a more abundant/diverse beneficial SOIL BIOTA -- stimulated by crop management practices that produce larger root systems
(more exudates).
The soil-plant microbiome, which parallels the human microbiome, has co-evolved with plants (like animals) with mutualistic, symbiotic relations.
Still much that we do not understand about it.Currently involved with Chinese scientists (CAS) in transcriptomic analysis of rice-rhizobia interaction.
Effects of inoculation with Rhizobium leguminosarum bv. trifolii E11 on root architecture of two rice varieties: (a) Rootlets per plant; (b) Cumulative root length (mm); (c) Surface area (cm2); (d) Root biovolume (cm3). From: Y. G. Yanni et al., Australian Journal of Plant Physiology, 28, 845–870 (2001)
Research from Egypt shows positive interactions between soil microbes and
root system’s growth
Effects of cultivation practices and nutrient amendments on levels of root-endophytic bacteria (Azospirillum), tillering, and yield
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
“Ascending Migration of Endophytic Rhizobia from Roots to Leaves inside Rice Plants, and Assessment of Benefits to Rice Growth Physiology” F. Chi et al., Applied &
Envir. Microbiology 71 (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/po
t(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 Sino-rhizobium meliloti 1021” F. Chi et al., Proteomics 10 (2010) –
-- evidence of significant up-regulation/down-regulation of gene expression in rice plant roots, leaf sheaths and leaves
Data are based on the average linear root and shoot growth of three symbiotic (dashed line) and three non-symbiotic (solid line) plants.
Arrows indicate the times when root hair development started.
Fungi also make positive contributions to plant growth:
Ratio of root:shoot growth in symbiotic vs. non-symbiotic rice plants – comparing seeds inoculated with Fusarium
culmorum vs. controlsR.J. Rodriguez et al., ‘Symbiotic regulation of plant growth,
development and reproduction” Communicative and Integrative Biology, 2:3 (2009).
Onset of root hair growth ↑
Inoculated seeds
Uninoculated seeds
Compare growth of rice seedlings -- non-symbiotic (left) and symbiotic (right) – in terms of effect that inoculating seeds with a fungal endophyte (F. culmorum) has on root growth and root hair
emergence --from Rodriguez et al. (2009).
Research assessing positive effects of SRI management practices on soil microbial populations in rice-plant rhizospheres – thesis research done at Tamil Nadu
Agricultural University, 2002,
Results of comparative microbiological analyses of SRI vs. non-SRI rhizospheres by scientists at Tamil Nadu
Agricultural University and ICRISAT in India and at Institut Pertanian Bogor (IPB) in Indonesia; I. Anas et al., Paddy
and Water Environment, 9:1 (2011)
Huge range -- average increase 84%
“Relationships observed between Trichoderma inoculation and characteristics of rice grown under System of Rice Intensification
(SRI) vs. conventional methods of cultivation.” F. Doni et al., Symbiosis (2016).
Much more remains to be researched and learned about these relationshipsBasic-science knowledge is expanding rapidly, but agricultural R&D remains mostly encased in the orthodoxy of the
Green Revolution which ignored both ROOT SYSTEMS and the SOIL BIOTA
We need to move beyond GR orthodoxy and consider science-supported heterodox views.
This new knowledge is coming at a crucial time when we are having to cope with CLIMATE CHANGE while continuing to combat POVERTY and HUNGER
With knowledge becoming available, we should be able to meet SDGs #1 and #2 and to make progress on SDG #3 – but we will need to reorient our agricultural R&D more toward agroecological knowledge and practice
CA and SRI/SCI are members of a larger family of production systems and practices that derive from agroecological insights and experience
Advanced, reductionist science should be working with integrative, holistic perspectives: link biology and ecology and build on advances in microbiology and epigenetics to understand better how and why genes are expressed.
AGRICULTURE is ultimately about gene expression.
http://info.worldbank.org/etools/docs/library/245848/index.html