Post on 30-Aug-2020
transcript
More Genes or More Agronomists?
Paul E. FixenInternational Plant Nutrition Institutepfixen@ipni.net
Achim DobermannInternational Rice Research Institute
a.dobermann@irri.org
ASA, CSSA, SSSA 2010 Annual MeetingOct. 31- Nov. 4 Long Beach, CA
Special Session: Challenges in Achieving a Second Green Revolution
More genes or more
agronomists?
Maize in the U.S.
Rice in Brazil
Optimistic claims on the impact of additional gains for maize from biotechnology
•Boost average U.S. maize yields to 19 Mg ha-1 (300 bu/A) by 2030 (Monsanto, 2008).
• Single transgene interventions for drought tolerance providing additive 15% yield jumps every 5 years (Edmeades, 2008).
Potential to lead to the under valuing of other factors in advancing these traits
2
4
6
8
10
12
1965 1970 1975 1980 1985 1990 1995 2000 2005 2010
Gra
in y
ield
, Mg
ha-1
Year
118 kg/ha-yr
[1.9 bu/ac-yr ]
USA Corn Yield Trends, 1966-2009
Double-X to single-X hybrids
Expansion of irrigated area, increased N fertilizer rates
Soil testing, balanced NPK fertilization, conservation
tillage
Transgenic (Bt) insect resistance
Integrated pest management
Precision, high-speed planters
Modified w/ permission: Cassman et al., 2006. Convergence of Agriculture and Energy. CAST.
(underpinning stream of tremendous technological innovation)
Auto-steer tractors
Nitrogen Partial Factor Productivity for Corn in the U.S. … substantial gains as yields climbed
Yet cereal grain crop recovery often ranges below 50% in season of application
Source of future gains?
Long-term average maize yields in the Nebraska ecological intensification study
Cont. corn Corn/soybeanMg/ha
Lancaster County irrigated farmer avg 10.6University recommendation 14.0 14.7Intensive high yield management 15.0 15.6
2000-2005.
Study yields from Dobermann et al., 2007.
Irrigated maize in south-Central Nebraska
• 3-county avg irrigated yield = 12.1 Mg ha-1 (2001-2008)• Hybrid-Maize model used to define potential yield (Yp) for each
field-yr and for yield gap estimation– Simulation without limitations from nutrients or pests
Grassini et al., 2010. Field Crops Research.
• Tri-Basin Natural Resources District
• Empty circles = 521 fields in the database
• Solid circles = 123 fields with additional crop management data
Tri-Basin irrigated yields and simulated yield potential based on avg management practices and weather records
Dashed line based on practices giving highest yd (RM, pop, sowing date)
8-yr avg = 12.1• 21% below avg Yp• 31% below max Yp
Risk factors:• Frost before PM• Harvest problems• Seed costs, lodging
Authors: “… limited potential for further increases in irrigated maize yields without a substantial increase in the current Yp ceiling. … brute force breeding … agronomic research … to exploit interactions.”
Grain yield per hybrid regressed on year of hybrid release for three plant densities
As in the past, future yield increases will not be due to genetic improvement alone, but to changes in several interacting factors, with
better agronomy always playing a major role..
Hammer et al., 2009.
Observations on these high yield maize systems• Continuous yield and efficiency improvement appear
associated with both genetic and agronomic changes•None of the genetic interventions have increased the Yp
of maize; they helped reduce yield gaps and enabled better management.
•Agronomic factors interact in complex ways … but well-informed farmers sort through them rather effectively
•Approaching a Yp ceiling in many productive maize growing areas of the U.S.
– What is the water-limited Yp ceiling for rainfed U.S. maize at the farm-level?
Rice in Southern
Brazil
Cerrado
Rice area, production and yield in the Southern Cone, South America
Yiel
d to
n/ha
Green revolution(small contribution
from agronomy)
350 Dwarf varieties released without much impact
Impact of semi – dwarfs
2 ton/ha
Agronomic Revolution(little variety contribution)
Limit: varieties with higher yield potential
Impact 2 ton/ha
Creation of FLAR
.................................1968 1995 2002.......................................
Years
?
?
Variety revolution II?
Peter Jennings, FLAR, 2005
“A package of practices to address multiple problems all at once … a 2nd revolution.”
Latin American Fund for Irrigated Rice (FLAR)South – South platform that seeks synergy in rice R & E
• Established in 1995• A strategic alliance among public
and private institutions of LA rice sector
• Annual fee based on country rice production
– Total budget of $1.4 million• Projects on:
– Breeding– Agronomy to reduce country
yield gaps (in 19 countries)– Economy and markets
Precision management: small details make big differences
1. Plant for maximum yield potential2. Optimize your plant population3. Preventive pest management4. Early weed control5. Balanced nutrition6. Irrigate early & well
6 strategic practices that are NOT site-specific
Precision management practices in RS1. Plant early to maximize yield potential
– Choose right variety; land preparation after harvest
2. Reduce seed rate to 70-80 kg/ha3. Preventive pest management
– Seed coating (insecticide, fungicide); fungicide (PI-F)
4. Preventive and early weed control:– Pure seed; Clearfield varieties, crop rotation– Herbicide at V3-V4
5. Balanced nutrition with high NUE– Basal NPK placed with seed (2” x 2”)– High N dose at V3-V4 on dry soil (pre-flood)– Topdress N at PI (airplane)
6. Irrigate early– Irrigate at V3-V4 and keep flooded– Harvest and recycle water
Instituto Rio Grandense do Arroz (IRGA)• 420 Staff• Research & extension• $30 million/yr• 100% farmer-funded• $0.20/sack rice
• 6 Regions• 40 Offices• 38 Agronomists• 22 Technicians• 9.000 farmers• 1.1 million ha
2009
Rice yields – RS Brazil (1987-2007, IRGA)
Faixas de produtividade<5 5,1-6 6,1-7 7,1-8 8,1-9 9,1-10 >10
Áre
a cu
ltiva
da c
om a
rroz
- %
0
5
10
15
20
25
30
35
20002008
1,7
7,8
27,7
22,3
6,4
0,8
30,2
27
22,8
33,3
13,3
4,7
1,90
Yield distribution among rice farms in RS, Brazil in 2000 and 2008
Instituto Rio Grandense do Arroz
33,48 33,0030,91
26,64
24,12
26,19
15,00
20,00
25,00
30,00
35,00
2002/03 2003/04 2004/05 2005/06 2006/07 2007/08
Custo unitário (R$/saco 50kg)
- 21,8%
Average cost of production
Water use efficiency in RS
4 m3/1 kg of rice
≤ 1 m3/1 kg of rice
2 m3/1 kg of rice
Key elements of success• Systematic approach for better agronomy instead of a
fragmented product-centric approach • Common goal and agronomic principles that can be easily
communicated and implemented• Large-scale technology solutions that match farmers’ needs• Focus on farmer-to-farmer extension• Extension support mechanisms
– Knowledgeable, motivated field agronomists (IRGA, private consultants)
– Local partnerships (technical working groups)– Focused applied research program (IRGA)
• Self-sustained: paid and driven by farmers• Teamwork
IPNI Global Maize Project: Objectives• Determine and demonstrate the yield gap
in various maize regions of the world.• Determine what nutrient management and
other practices need to change to close the yield gap faster than the current trajectory.
Local teams consisting of researchers, farmers, agronomists and agri-business define treatment specifics
• Farmer foundations:– Mato Grosso Foundation– ABC Foundation
• Provide critical linkages• Eager to participate in the
new “flat world” of agronomyResearchers, farmers &
agronomists at Rondonopolis
• Adaptive research linked to adaptive management: – Transforms good practices based on scientific principles into
best practices based on local practical experience– Potential to shorten the time between discovery and impact.
Site factors
Crop SoilFarmer InputsWater qualityClimateWeatherTechnologyEconomics
Decision
Action
OutcomeFeedback loop
Output
Recommendation of right practice, product,
variety, rate, etc.
A schematic of adaptive management … and research
After Fixen, 2007.
Productivity, profitability,durability, environmental impact
Decision Support
Based on scientific principles
Stakeholder input
Parallel adaptive research?
J.B. Passioura, 2010 (CSIRO)
More Genes or More Agronomists?
ASA, CSSA, SSSA 2010 Annual MeetingOct. 31- Nov. 4 Long Beach, CA
Special Session: Challenges in Achieving a Second Green Revolution
Both, but with appropriate balancebetween them in research
investment, adaptation, and adoption
Is that where we are today?
(USDA, 2008; Dept. of Labor, 2008) Compiled by Chris Boomsma, Purdue U.
2006
US$
mill
ion
1998 2000 2002 2004 20060
10
20
30
40
50
60
Year
E Cumulative USDA-Hatch, NRI, NSF, and DOE funding of basic and applied areas of crop improvement research
Genome, genetics, and genetic mechanisms [1]Genetic resources and biodiversity [2]Basic plant biology [3]Biological efficiency and abiotic stresses [4]Product quality and utility [5]Production management systems [6]
Predominately basic
Mixture of basic & applied
Predominately applied
Year1986
19891992
19951998
20012004
Ph.D
. gra
duat
es
0
20
40
60
80
100
120
140
160
Agronomy and crop sciencesPlant breeding and genetics
(USDA, 2008) Compiled by Chris Boomsma, Purdue U.
U.S. land-grant university Ph.D. graduates in agronomy and crop sciences and plant breeding and genetics
More Genes or More Agronomists?
ASA, CSSA, SSSA 2010 Annual MeetingOct. 31- Nov. 4 Long Beach, CA
Special Session: Challenges in Achieving a Second Green Revolution
Both, but with appropriate balance