INVESTIGATING CONSERVATION INVESTIGATING CONSERVATION AGRICULTURE SYSTEMS IN ZAMBIA AND AGRICULTURE SYSTEMS IN ZAMBIA AND

ZIMBABWE TO MITIGATE FUTURE ZIMBABWE TO MITIGATE FUTURE EFFECTS OF CLIMATE CHANGEEFFECTS OF CLIMATE CHANGE

By Christian Thierfelder and Patrick C. WallBy Christian Thierfelder and Patrick C. Wall

Table of content IntroductionIntroduction

Brief description of trial sitesBrief description of trial sites

Effects of CA on infiltration Effects of CA on infiltration and soil moistureand soil moisture

Yield responses to soil Yield responses to soil moisturemoisture

ConclusionsConclusions

Introduction:Introduction:Most models suggest that the southern African region will be Most models suggest that the southern African region will be affected by climate changeaffected by climate change

IPCC, AR4, 2007IPCC, AR4, 2007

Effect of climate change on crops in Effect of climate change on crops in southern Africasouthern Africa

The big losers in The big losers in southern Africa in southern Africa in terms of production terms of production will be maize and will be maize and wheatwheat

(Lobell et al., 2008. Science)

Farmer need to adapt to the new situation!

Change in management (date of planting)Change in management (date of planting)

Change in variety e.g. to shorter (or longer?) Change in variety e.g. to shorter (or longer?) season varietiesseason varieties

Change in fertiliser use (targeting and Change in fertiliser use (targeting and concentrating fertilizers)concentrating fertilizers)

Change in crops - e.g. to more drought resistance Change in crops - e.g. to more drought resistance speciesspecies

Change towards Change towards water-efficient cropping systemswater-efficient cropping systems

Water efficient cropping systemsWater efficient cropping systems::

Retain more water on-site through:Retain more water on-site through:

Higher infiltrationHigher infiltration

Less water run-offLess water run-off

Reduced evaporationReduced evaporation

Higher water storage in Higher water storage in the soil the soil

Higher biological activity Higher biological activity (earthworms create soil (earthworms create soil pores)pores)

The more water can be retained and stored on-The more water can be retained and stored on-site the more there is available for crop site the more there is available for crop

production!production!

Effects of CA on Earthworm counts, Effects of CA on Earthworm counts, Monze, FTC, Zambia 2007Monze, FTC, Zambia 2007

What is Conservation Agriculture?What is Conservation Agriculture? CA comprises the following

principles:

– Minimal soil movement

– Surface crop residue retention

– Crop rotations and green manure cover crops

LocationsLocations

Henderson Research Station (HRS), Mashonaland Central Province, Zimbabwe17.57°S, 30.99°E, 1136 m.a.s.l

Monze, Farmers Training Center (MFTC), Zambia16.24°S, 27.44°E, 1103 m.a.s.l

Brief description of treatmentsBrief description of treatments

Conventional ploughing, maize, no residues

CA: direct seeding, maize, residue retention

CA: direct seeded rotation, maize after cotton, residues retention

Conventional ploughing, maize, no residues

CA: direct seeding, maize, residue retention

CA: rip-line seeding, maize, residue retention

Henderson Research Station, Zimbabwe (HRS)Henderson Research Station, Zimbabwe (HRS)

Monze, Farmer Training Centre, Zambia (MFTC)Monze, Farmer Training Centre, Zambia (MFTC)

Infiltration curves measured by mini-rainfall simulator in January 2008 (left) and 2009 (right) in two conservation agriculture and one conventional treatment, Henderson Research Station, Zimbabwe

January 2008January 2008 January 2009January 2009

Infiltration curves measured by mini-rainfall simulator in January 2008 (left) and 2009 (right) in two conservation agriculture and one conventional treatment, Monze, Farmer Training Centre, Zambia

January 2008January 2008 January 2009January 2009

Crops are at tasselingCrops are at tasseling

Available soil moisture in the first 60cm at the Monze Available soil moisture in the first 60cm at the Monze Farmer Training Centre, Zambia, 2005/2006Farmer Training Centre, Zambia, 2005/2006

Crops are at tasselingCrops are at tasselingCrops are at tasselingCrops are at tasseling

Soil moistureSoil moisture

measurements,measurements,

Monze, FTC,Monze, FTC,

2008/20092008/2009

Initial crop Initial crop developmentdevelopment

Available soil moisture in the first 60cm at the, Monze Available soil moisture in the first 60cm at the, Monze Farmer Training Centre, Zambia, 2008/2009Farmer Training Centre, Zambia, 2008/2009

Initial crop Initial crop developmentdevelopmentInitial crop Initial crop developmentdevelopmentInitial crop Initial crop developmentdevelopment

Maize grain yield in four consecutive years at Monze Maize grain yield in four consecutive years at Monze Farmer training Centre, 2005-2009Farmer training Centre, 2005-2009

Maize grain yield in five consecutive years at Maize grain yield in five consecutive years at Henderson Research Station, Zimbabwe, 2004-2009Henderson Research Station, Zimbabwe, 2004-2009

Conclusions: CA has the potential to improve the soil water balance CA has the potential to improve the soil water balance

of major cropping systems in southern Africa and of major cropping systems in southern Africa and mitigate seasonal dry spellsmitigate seasonal dry spells

At HRS, Zimbabwe and MFTC, Zambia a generally At HRS, Zimbabwe and MFTC, Zambia a generally higher infiltration and soil moisture content was higher infiltration and soil moisture content was discovered on CA plotsdiscovered on CA plots

Conclusions: contd...... However, in some cases, higher soil moisture did not However, in some cases, higher soil moisture did not

transform into higher maize yieldstransform into higher maize yields

Higher available soil moisture will reduce the risk of Higher available soil moisture will reduce the risk of crop failure and therefore contribute to improved crop failure and therefore contribute to improved livelihood of African smallholder farmers.livelihood of African smallholder farmers.

THANK YOUTHANK YOU