Intensifying legume/cereal cropping
systems in Malawi
Regis Chikowo1, Christian Thierfelder2, Wezi Mhango3, and Rowland Chirwa4
1Michigan State University (MSU), 2International Maize and Wheat Improvement Center
(CIMMYT), 3Lilongwe University of Agriculture and Natural Resources (LUANAR),
4International Center for Tropical Agriculture (CIAT)
Africa RISING ESA Project review and planning meeting
11 – 12 September 2019, Dar es Salaam, Tanzania

Legumes and sustainability
• Legume integration in maize based systems increase soil health and
productivity
• Groundnut, soyabean, pigeonpea are now widely grown in Malawi.
• Low yields reported due to constraints such as poor soil
fertility, low plant density, poor seed
• High N content legume residues (even in small quantities) have a
large effect on N cycling and SOC development
• SOC status explains a large proportion of poor crop yields, as it
determines early crop growth and regulates soil N and P availability

Alarming yield gaps
Crop Actual yields
(t/ha)
Attainable yields
(t/ha)
Maize 1 4+
Soyabean 0.6 1.8+
Groundnut 0.6 1.5+

The story I love to tell

Double row groundnut

Introducing improved germplasm and appropriate
management - the possibilities..

Maize/bean intercropping

And if complexity is increased, how are soil
processes impacted? What about SI indicators…

Pigeonpea integration…

Pigeonpea belowground biomass assessments
0 - 20 cm
20 - 40 cm
40 - 60 cm

Legume-based cropping systems and soil
aggregation/SOC sequestration
Agglomeration of
soil particles + OM
to form micro-
aggregates
(occlusion of OM)
Agglomeration of
micro-aggregates to
form macro-aggregates
POM (plant
debris)
soil
particles
plant roots
enmeshing
macro-
aggregates
mucilage
+ root
exudates fungal
hyphae

The underlying biochemical process

We need this at scale

Yield, stability and nitrogen use efficiency of maize
in response to different legume technologies

Refining groundnut agronomy
Factors
• Seed quality : recycled and certified
• Density : single row and double row
• Varieties : Nsinjiro and CG7
Study sites:
• Dedza – Linthipe EPA (medium-High Potential)
• Machinga- Ntubwi EPA (low potential)

Single or double row groundnut production –is
there a seed quality effect?
The picture can't be displayed.

Refining groundnut agronomy……..
0
500
1000
1500
2000
2500
certified recycled certified recycled
DOUBLE ROW SINGLE ROW
Yield(kg/ha)

Bean grain yield and yield components in pure
stand and maize bean intercrop
0
200
400
600
800
1000
1200
1400
1600
1800
2000
SER
83
D
om
w
e
N
U
A
45
M
A
C
M
aize+D
om
w
e
M
aize+N
U
A
45
M
aize+SER
83
M
aize+M
A
C
KG/HA
Total Biomass
Pod weight
Grain yield

Maize grain yield in pure stand and maize-bean
intercrop – maize yield penalty large with NUA45
0
1000
2000
3000
4000
5000
6000
7000
M
aizeM
aize+M
A
C
109
M
aize+S
ER
83M
aize+D
om
w
e
M
aize+N
U
A
45
KG/HA

Getting extra benefits with
conservation agriculture

Improved maize legume systems under
conservation agriculture

Research Questions in the CA trials
• How to sustainbly intensify maize-legume farming systems under CA in
Southern and Central Malawi?
• What are their effects on productivty, profitability, the environment as
well as social and human indicators?
• What is their longer term effect on water-and nutrient-use efficiency,
climate resilience, reduction in soil degradation, pest and weed dynamics?

CIMMYT‘s regional trials on CA
In Malawi:
• Work in 10 target
communities with 6 trial
replicates in each
• Setup in paired-plot designs
testing two CA options
against a conventional
control
• All maize-based systems:
rotated with groundnut/
pigeonpea doubled-up
systems in Central
• Rotated with pigeonpea or
cowpea in Southern Malawi

During field tours.....

Average maize yields in Central and Southern
Malawi in on-farm trials

Legume response in Central and Southern Malawi

SOC is a good proxy
for soil productivity

Precision agriculture through hand-held
reflectometer monitoring of soil organic carbon
• SI technologies improve SOC
• However, quick ways to get SOC content have remained elusive
• More than 1,100 soil samples from Central and Southern Malawi
were scanned using the OurSci Reflectometer
• A regression model was trained to predict whether SOC was over
or under a 1% C threshold.

Precision agriculture through hand-held
monitoring of soil organic carbon

Conclusions
• Farmers grow more maize by growing more legumes (its about
efficiencies)
• Refining agronomic practices and understanding farmer preferences
is important
• Where possible, CA can be implemented to reap more land
management benefits
• We have found a panacea to the problem of lack of data on SOC –
we are piloting to scale the hand help reflectometer up with Malawi
Government

Africa Research in Sustainable Intensification for the Next Generation
africa-rising.net
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