Are durum wheat-grain legume and sunflower-soybean intercrops efficient solutions to produce legume in low input systems? Laurent BEDOUSSAC, Etienne-Pascal JOURNET, Hélène TRIBOUILLOIS, Grégory VERICEL, David CHAMPCLOU, Nathalie LANDE and Eric JUSTES
UMR AGIR INRA-INPT Toulouse – France
1st Legume Society Conference, Novi Sad, Serbia, 9-11 may 2013
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Intercrops=Mixed crops: Simultaneous growing of two
or more species in the same field for a significant period without necessarily sowing and harvesting them together (Willey 1979)
≠ of cover crop during fallow period
Intercropping is an application of natural ecosystems ecology principles (biodiversity, species interactions, integrated protection…e.g. Vendermeer, 1989) but rarely cultivated except for animal feeding
Separated rows
Mixed on the row or
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Intercrops and species functional complementarity Species complementarity could allow a better use of available ressources (water, light, nitrogen…) in time and space Photosynthetically active radiation
Water & Nutrients
Soil Mineral N (NH4+, NO3-)
Percentage of N derived from air (%Nacc)
Atmospheric N2 fixation 100 90
Sole cropped Pea
Intercropped Pea
Nefer – Lucy ; Unfertilized treatments
15N
natural abundance method
80
(Shearer and Kohl 1986)
70
% Ndfa
60
100
50 40
15 N ref 15 N pea 15 N ref β
20
δ15Nref = IC wheat β = -1‰
10
(Voisin et al. 2002)
30
3
0 2005-2006
2006-2007
Interests of intercrops for low input systems • Improve cereal grain quality (grain protein content) (Jensen, 1996; Hauggaard-Nielsen &al 2001a; 2009, Bedoussac & Justes, 2010a)
• Increase global yield (compared to low input sole crops) (Hauggaard-Nielsen &al 2001a; Zhan &al, 2010; Bedoussac & Justes, 2010a)
• Reduce weeds (compared to legume) (Hauggaard-Nielsen &al 2001b, Corre-Hellou &al, 2011)
• Potentially reduce pests (e.g.pea aphids) and diseases (hypothesis widely cited, e.g. Vendermeer, 1989; but no demontration published)
• Reduce the nitrate leaching risk (compared to sole legumes) (Hauggaard-Nielsen &al 2003; 2009, Bedoussac & Justes, 2010b)
• Increase yield stability (compared to sole crops) (hypothesis widely cited, e.g. Vendermeer, 1989; but no demontration published)
• Increase or stabilise over years the farmer gross margin (Bedoussac, 2009; Pelzer &al, 2012)
• Improve football quality (Winners of the 2013 legume world cup)
Lots of references for cereal-grain legume IC and few limits highlighted by the scientific community but only few references for sunflower-soybean IC !!!
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Examples of key results on durum wheat-winter pea intercrops: Efficiency for yield
Land Equivalent Ratio for Yield
Wheat (Nefer) – Pea (Lucy) in 2005-2006 and 2006-2007
1,4
LER Durum wheat
LER Pea
1,2
Land Equivalent Ratio (LER) = an indicator of IC performances (e.g. Willey, 1979) ; LER = relative land area under SC required to produce the yield achieved in IC. LER is the sum of partial LER for each species (LERP and LERW)
LER LER P LER W
1,0 0,8
LER W
0,6
YW IC YP IC ; LER P YW SC YP SC
• LER ≥ 1 in LOW N SYSTEMS IC up to 20% more efficient
0,4 0,2 0,0 N0
N100
N180
2005-2006
(Bedoussac & Justes, 2010a & b)
• LERW ≥ 0.5 and LERP ≤ 0.5 N0 N60+took advantage N80 N140 Wheat of IC, not Pea 2006-2007
• LER widely used and abused while doesn’t compare species yields Other indices more adapted
(Bedoussac & Justes, 2011)
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Examples of key results on durum wheat-winter pea intercrops: Grain quality Nefer - Lucy Intercropped Wheat Grain Protein Content (%DW)
Wheat (Nefer) – Pea (Lucy) in 2005-2006 and 2006-2007
y=1.2x
y=1.1x
y=x
15 Exp. I and II y = 0.67x + 5.27 R2 = 0.87***
• IC GPC higher than in SC at the same N level • The lower the SC Wheat GPC, the larger the increase IC more adapted to low N input systems
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2005-2006 (Exp. I) N0 N100 N180
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2006-2007 (Exp. II) N0 N60+ N80 N140
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• Why larger amount of N available per grain in IC ? Lower IC wheat yield vs. SC but almost same amount of N available (high pea N2 fixation in IC)
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9
11
13
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Sole cropped Wheat Grain Protein Content (%DW)
(Bedoussac & Justes 2010a, 2010b)
Niche complementarity for N sources combined with 6 light competition
Summer IC practical aspects : Sowing once, harvesting twice TSu SSo SSo SSo S T So Su
2/4 67/33
2 Substitutive row design structures
T So S So S Su T Su
2/2 50/50
Sowing at the same time : Early to End of May
Harvesting in two times : 1st Sunflower : Mid-September 2nd Soybean : End-September / beginning of October
Sunflower row distance depends on that of wheels !!!
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Examples of key results on summer intercrops: Grain yield
Partial Soybean fertilizaton to compensate inefficient inoculation
Auzeville 2010
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Soybean
Sunflower
Yield (Mg ha-1) .
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T S S T Su So So Su
TSu SSo SSo SSo SSo Su T
or
3 2/2 50/50
2
2/4 67/33
• 4 cultivars : 2 Soybean cv. : Isidor (eSo = early) Ecudor (lSo = late)
1 0 eSo lSo eSu lSu
2/2
SC Soya
eSo-eSu
SC Sunf.
2/4
2/2
2/4
eSo-lSu
2/2
2/4
lSo-eSu
2/2
2/4
lSo-lSu
LER = 0.96 ; 1.16* ; 0.96 ; 1.10* ; 1.04 ; 1.21* ; 0.92* ; 1.17*
• • • •
• 2 designs :
2 Sunflower cv. : Fabiola (eSu = early) Melody (lSu = late)
IC total grain yield > SC Soybean and < SC Sunflower More Soybean in the 2/4 and with late cultivar (lSo) Always more Sunflower (except 2/4 with lSo) LER always > 1 with the 2/4 design but not for 2/2
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Examples of key results on summer intercrops: N Acquisition Non limiting resources : 50 mm water ; 360 kg N/ha
CETIOM 2010
Sunflower 70
250
• 2 designs :
60
N2 fixation rate (%)
N accumulated (kg N/ha)
Soybean
200 150 100 50 0
T S S T Su So So Su
50
or
40
2/2 50/50
30
2/2
2/4 67/33
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• 2 cultivars :
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1 Soybean : Ecudor (lSo = late)
0
SC Soy. SC Sunf.
TSu SSo SSo SSo SSo Su T
Border
2/4 SC Soya Soya 2/2
Center
Soya 2/4
1 Sunflower : Melody (lSu = late)
• Shoot N accumulated by the whole IC ≤ to that of the sole crops • SC Soybean N2 fixation rate low (high initial N soil min. content) • Higher N2 fixation rate in IC • Higher N2 fixation rate in border rows according to sunflower uptake and competition for soil N 9
5 Taller Soybean Cultivar
3
Earlier Soybean Sowing Date
2 1
Maximum Sunflower competition
May
June
Soybean sowing
July
Soybean Flowering
Sunflower Harvest
August
1700°C
0
950°C
Sunflower Flowering
850°C
Sunflower E1 stage (star buton)
630°C
Sunflower Sowing
LAI (m²/m²)
4
September
Soybean Harvest
1900°C
Sunflower height Soybean Height Soybean LAI Sunflower LAI
530°C
Height (cm)
Increasing complementarity : Adapting cultivar or sowing date
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Conclusions and perspectives Agronomically, the most efficient intercrops were in low input systems (highest complementarity in time, space & resources) No N and no irrigation for the 2/4 sunflower-soybean IC No or low early N availability for cereal-legume IC Need for more knowledge to optimise cropping system designs according to different objectives Need for a better understanding of dynamical interactions and effects of cover structure with pedoclimatic conditions
Interest of a modelling approach (first step using the soil-crop model, already adapted to intercrop)
Which legume cultivars for cereal-legume IC ? Which effects of IC on pests and diseases ? How introducing IC in supply chain (& rotation) ? Which economical efficiency ?
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Hvala (thank you) This work was supported and funded by INRA and ANR (French Agency for Research) Special thanks for François, Stefano & Alexandra Perfcom project MicMac-design project http://www4.inra.fr/micmac-design_eng/ POSTERS : •
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Reducing biotic stresses in legumes through intercropping with durum wheat. Laurent Bedoussac, Etienne-Pascal Journet and Eric Justes Breeding legume to improve durum wheatgrain legume intercrops efficiency. Bochra Kammoun, Laurent Bedoussac, Etienne-Pascal Journet and Eric Justes
ORAL (Session 5) : •
Contacts:
Agricultural innovative practices and impacts of the supply chain: An ex-ante study of the logistics of agricultural cooperatives to estimate the acceptability of durum wheatgrain legumes intercrops. Laurent Bedoussac, Marie-Benoit Magrini, Pierre Triboulet
[email protected] [email protected]
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Results : Half direct margin Sunflower : 307 €/t & 357 €/t in org. ; Soya : 281 €/t & 381€/t in org.
treatment
seeds
inoculum
Harvest
molluscicide
herbicide
insecticide
fungicide
IRRIGATION
PESTICIDES
harvest
SOYBEAN
seeds
SUNFLOWER
2 Su/ 2 So 2 Su/ 4 So sunflower soybean Org. Prices 2 Su/ 2 So 2 Su/ 4 So INRA sunflower experiment soybean (low input)
50 33 100 50 33 100 -
95 95 95 95 95 95 -
96 128 192 96 128 192
15 20 30 15 20 30
120 120 120 120 120 120
20 20 20 20 20 20 20 20
86 86 86 86 14 14 14 14
26 26 0 26 0 0 0 0
28 28 28 0 0 0 0 0
30 30 30 0 0 0 0 0
xperiment
CETIOM experiment (high input)
Without Subsidies
Margin Mean Total (€/ha) SC Margin input (€/ha) costs 566 586 359 474 410 430 229 376
624 491 1080 454 680 791 1108 555
767 663
831 739
• IC margin > SC Soya but < SC Sunflower • IC margin < Mean SC margin (except 2/4 INRA) • IC costs > SC costs mostly because of double harvest 13 need to produce 12 to 16% more yield in IC for the same margin
How to improve complementarity ?
Irena
Geronimo
Diver
AOPH10
Castel
Wheat height – Pea height (cm)
Begining of flowering Wheat height – Pea height (cm)
Begining of flowering
27%
26% 52% 62% Degree days (°C)
% of SC1/2 yield
Isard
Nordica
Faba cultivars Maximum height (cm)
Lucy
Maximum height (cm)
Pea cultivars
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Results: grain yield Isidor (eSo = early Soybean) ; Ecudor (lSo = late Soybean) Fabiola (eSu = early Sunflower) ; Melody (lSu = late Sunflower) Soybean
Exp. 2 CETIOM 2010 (N and Water non limiting)
Sunflower
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• IC total grain yield > SC Soybean and < SC Sunflower
Yield (Mg/ha)
4 3
• IC yield higher in 2/2 N and Water more favorable for Sunflower
2 1 0 SC Soya
SC Sunf.
2/2
LER = 0.92
2/4
;
0.85
• LER lower than 1 ... More competition for ressources than complementarity...
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