Maize-grain legume intercropping is an
attractive option for ecological intensification
that reduces climatic risk for smallholder
farmers in central Mozambique
Leonard Rusinamhodzi, Marc Corbeels, Justice Nyamangara, K.E. GillerPlant Production Systems Group - Wageningen University, CIRAD, ICRISAT-Bulawayo
Background…… Central Mozambique
Extensification systems Slash and burn Lack of inputs (manure, fertiliser, improved germplasm)
Extension support is severely indisposed
charcoal
Soils Predominantly sandy soils
Pockets of fertile red clays soils Current crop production systems lead to accelerated
loss of soil fertility
Time of cultivation (years)
0 5 10 15 20
SO
C (
t h
a-1
)
30
40
50
60
70
80
90
Time of cultivation (years)
0 2 4 6 8 10 12 14 160
20
40
60
80
Clay soil Sandy soil
How do we intensify in these systems?....
Basket of technologies exists but….. mismatch between farmers’ objectives
and technology outputs Farmers are interested in technologies
that ensure food security and cash income
Improving soil fertility
is seldom mentioned
Gra
in le
gum
es
Gre
en
manure
s
Agro
fore
stry
Fodder
legum
es
Manure
Fe
rtili
zer
s
Our approach -AfricaNUANCES Framework
NUtrient Use in Animal and Cropping Systems - Efficiencies and Scales.
Used to analyse current livelihoods, explore options for their development and reveal trade-offs
Mainly relied on field based methods (interviews, transect walks, FGD)
http://www.africanuances.nl/
Our approach
• Analysis of constraints and opportunities showed a strong bias towards maize-legume intercropping
• Farmers and development agents claimed that these intercrop systems were “working”
• Evidence and best-practice guidelines were missing
Maize-legume intercropping
Farmers in Ruaca preferred maize-pigeonpea intercropping Established market through CARITAS-Messica
In Vunduzi, farmers preferred maize-cowpea intercropping Food security was of primary concern
Our objective
To understand the farming systems, and to evaluate the suitability of maize–legume intercropping to alleviate the biophysical and socio-economic
constraints faced by smallholder farmers in central Mozambique
Study sites Ruaca
mixed-crop livestock system, Integration between
components is weak Vunduzi
Mostly crop based farming system
Vunduzi villageRuaca village
Field experiments
Maize-pigeonpea intercrops Within row (Maize 90 x 90, 3 plants per hill,
legume in between, 3 plants per hill) Distinct row (maize 90 x 30 ), 2 rows of maize alternate
with a row of legume)
All treatments simultaneously planted
Maize-cowpea intercropping Same arrangement as in maize-pigeonpea
intercropping Relay planting for maize/cowpea Planting and weeding performed
using hand hoe
Four fertiliser rates superimposed on intercrop treatments (i) no fertiliser, (ii) 20 kg P ha-1, (iii) 20 kg P ha-1 + 30 kg N ha-1, and (iv) 20
kg P ha-1 + 60 kg N ha-1
Results - rainfall distribution
Ruaca
0 20 40 60 80 100 120 140 160
Cum
ulativ
e rainfall (m
m)
0
200
400
600
800
1000
1200
2008/09 (19 November 2008)2009/10 (29 November 2009)2010/11 (21 November 2010)
Vunduzi
Days after planting
0 20 40 60 80 100 120 140 160
Cum
ulativ
e rainfall (m
m)
0
200
400
600
800
1000
1200
2008/09 (15 November 2008)2009/10 (18 November 2009)2010/11 (24 November 2010)
Long dry spells were common
Increased risk of crop failure especially for maize
Legumes more drought resistant
Maize- pigeonpea yield
Season × intercrop
interactions
were significant Pigeonpea
responded to
larger N
Pigeonpea
N-P applied (kg ha-1)
0-0 0-20 30-20 60-200.0
0.5
1.0
1.5
2.0Maize
N-P applied (kg ha-1)
0-0 0-20 30-20 60-200
1
2
3
4
5
6
Sole maize (2008/09)Sole maize (2009/10)Sole maize (2010/11)Distinct-row (2008/09)Distinct-row (2009/10)Distinct-row (2010/11)Within-row (2008/09)Within-row (2009/10)Within-row (2010/11)
Maize- cowpea yield
• Season (rainfall distribution) and crop arrangement were significant
• the interactions between fertiliser and intercrop treatments were weak for maize
• Response in cowpea due to improved rainfall later in the season
Cowpea
N-P applied (kg ha-1)
0-0 0-20 30-20 60-20
Cow
pea grain yield (t ha-1
)
0.0
0.5
1.0
1.5
2.0Maize
N-P applied (kg ha-1)
0-0 0-20 30-20 60-20
Maize grain yield (t ha
-1)
0
1
2
3
4
5
6
Sole maize (2008/09)Sole maize (2010/11)Distinct-row (2008/09)Distinct-row (2010/11)Within-row (2008/09)Within-row (2010/11)
Intercrop productivityTreatment Fertiliser Maize-pigeonpea
intercropping (Ruaca)Maize-cowpea intercropping
(Vunduzi)2008/09 2009/10 2010/
112008/0
9a
2009/10b
2010/11
Distinct-row
No fertiliser 1.1 1.1 1.4 - - 1.4
20 kg P ha-1 1.0 1.1 1.2 - - 1.8
30 kg N + 20 kg P ha-1
1.1 1.0 1.2 - - 1.7
60 kg N + 20 kg P ha-1
1.0 1.2 1.3 - - 1.9
Within-row No fertiliser 2.2 1.7 2.0 - - 2.4
20 kg P ha-1 1.4 1.7 2.4 - - 2.0
30 kg N + 20 kg P ha-1
1.4 2.0 2.0 - - 2.2
60 kg N + 20 kg P ha-1
1.5 1.9 2.1 - - 2.0
*SED 0.1 0.1 0.2 - - 0.2
• Within row
intercrops
more
productive
than distinct
row intercrops
Cumulative benefits of pigeonpea
N-P applied (kg ha-1)
0-0 0-20 30-20 60-20
Maize grain yield (t ha
-1)
0
1
2
3
4
5
6
7
8
Maize after pigeonpeaContinuous maizeDistinct rows intercroppingWithin row intercropping
• Continuous maize suffered from
Striga asiatica
• Small yield penalty in within row
intercropping
Time (minutes)
0 10 20 30 40 50 60 70 80 90 100 110 120
Infiltration rate (mm
hr-1
)
0
10
20
30
40
50
60
70
80
Continuous maize1 year intercropping3 year intercropping5 year intercropping
Duration of intercropping on rainfall infiltration
• Long-term large biomass production in combination with reduced tillage
Labour requirements of intercroppingTreatment Weeding number Total
1 2 3
Sole maize 6.0 4.8 6.7 17.6
Sole pigeonpea 6.5 5.0 6.7 18.2
Within row intercropping
8.2 6.2 7.9 22.3
Distinct row intercropping
9.1 7.8 9.6 26.4
SED 0.4
• Intercropping increased weeding time by 36%
compared to sole crops
• Need to take care of slow growing pigeonpea
• Movement is hampered when its grown
Partial budget analysis
Fertiliser Production option
MRR (%) at given price condition
Normal price Peak maize price Peak pigeonpea
pricePeak price
for both crops(+140%) (+50%)
No fertiliser Sole pigeonpea 3729 437 6819 3528
Within-row 667 1361 1112 1639
Distinct-row 343 621 465 743
Fertiliser (20 kg P and 30 kg N ha-1)
Sole pigeonpea 759 93 1326 660
Within-row 500 791 673 963
Distinct-row 472 472 758 758
• Farmers sold crops immediately when price were depressed
• Later in the year, maize prices rose 140%
• Pigeonpea prices rose by 50%
Farmer evaluation of intercrops Evaluation criteria Treatment (scoring scale 1-20)
Sole maize Sole pigeonpea
Distinct row intercrop
Within row intercrop
Food security (weight =5)
14 (70) 8 (40) 19 (95) 20 (100)
Cash income (weight =4)
6 (24) 18 (72) 16 (64) 20 (80)
Input costs (weight =3)
15 (45) 9 (27) 12 (36) 10 (30)
Ease of mechanical weeding (weight =2)
15 (30) 14 (28) 6 (12) 15 (30)
Time to maturity (weight =1)
14 (14) 4 (4) 12 (12) 12 (12)
Total score 183 171 219 252
Acceptability (%) 61 57 73 84
• Food security > income > input costs
• Sole legume not preferred
• Within row intercrop preferred
Diversity of farmers in study sites vs. intercropping
• PCA shows good correlation with locally identified RGs
• Ruaca, land size, number of cattle owned (4 RGs)
• Vunduzi, land size, number of goats and pigs (3 RGs)
Diversity of farmers and intercropping
In both sites, adopters were in the middle resource groups
The poorest were more interested in selling labour either for money or for direct food
Richer farmers especially in Ruaca had jobs in the city and wanted to be middle men for other farmers’ produce
Suitability of intercropping in the study sites
Ruaca Vunduzi
Land : labour ratio (ha person
-1)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
SED
0 1 2 3 4 5 6
Land utilization (%
)
0
20
40
60
80
100
VunduziRuaca
Land: labour ratio
0 1 2 3 4 5 6
Months of food self-sufficiency (year
-1)
2
4
6
8
10
12
14
Ruaca Vunduzi
Land utilization (%
)
0
20
40
60
80
100
Land: labour ratio
a b
c d
SED
• Ruaca - labour constraints due to extensification
• Intensification necessary will reduce labour demands
• Vunduzi- land limitation
• rugged terrain + National Park
Seasonal changes in # of farmers practicing maize-
pigeonpea intercropping
• Market for pigeonpea was a driver for uptake of pigeonpea
• Destruction by cattle was problematic in Ruaca
Pigeonpea vs. communal grazing
• late maturity of pigeonpea delays free-grazing of cattle
• allows farmers to retain crop residues as mulch if they choose to
• use of ‘ratoon’ pigeonpea reduces costs of seed and the need for tillage
Relay intercrop vs. climatic riskVunduzi (2009/10 season)
Days after planting
0 20 40 60 80 100 120 140 160
Cum
ulative rainfall (mm
)
0
200
400
600
800
1000
54 Days
• Relay intercropping reduces climatic risk of total crop failure
Conclusion
Maize–legume intercropping has potential to:
(a) reduce the risk of total crop failure,
(b) improve productivity and income, and
(c) increase food security in vulnerable production systems, and is a feasible entry point to ecological intensification.
Muito obrigado pela sua atenção!...............