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!...............