Maize Yield Increases and Stabilization under CA in semi-arid Districts of Tanzania

bySaidi Mkomwa1; Zakaria Mkoga1;

Wilfred Mariki2 and Marietha Owenya2 1African Conservation Tillage Network (ACT);2Selian Agricultural Research Institute (SARI)

Presented atThe Fifth World Congress on Conservation Agriculture,

Brisbane Convention & Exhibition Centre, Brisbane Australia26 – 29 September 2011

Contents

1. Introduction 2. Materials and Methods3. Results and Discussions4. What are the Implications for smallholder

adoption of CA?5. Acknowledgements

Introduction–study sites &farmers

CA SARD project phase 2 from 2007 to March 2011. Funded by German Govt, Implemented by FAO with the Tanzania and Kenya Governments8000 households learned CA by doing

Scaling Up CA in Africa

CA SARD PROJECT

Materials and Methods Study of 8 FFS from Arumeru & Karatu

Districts, Arusha Region Tanzania For three consecutive years from 2005

to 2007. Gender mixed farmer groups with 20 –

25 farmers each cultivating about 2ha. Learning CA by experimenting with

alternative crop production technologies

Treatments

1. Jab planter, glyphosate weed control, lablab cover crop planted after first weeding,

2. Ripping, glyphosate weed control, jab planting in the ripper furrow, pigeon peas intercrop,

3. Jab planter, glyphosate weed control, pigeon peas intercrop,

4. Ripping, glyphosate weed control, jab planter, lablab cover crop and

5. Farmers practice - ox ploughing, hand hoe weed control.

Oxen ripping

Oxen direct seeding

Jab planting

Schematic Plot-layout vs Treatments  Plot 1

JabPlot 2

RipperPlot 3Jab

Plot 4Ripper

Plot 5Plough

TILLAG

E

None Reduced; AD ripper

None Reduced; A/Drawn

ripper

Farmer’s Practice –(Plough)

SEED

PLA-CEMENT

Jab planter

AD direct seeder

Jab planter

AD direct seeder

Hand hoe (for Maize & Beans)

COVER

CROP

Lablab Pigeon peas

Pigeon peas

Lablab Traditional (Beans -

crop)

  Plot 1Jab

Plot 2Ripper

Plot 3Jab

Plot 4Ripper

Plot 5Plough

MAINTENANC

E OF SOIL

COVER

Maize stover tops

only removed

All residues retained

All residues retained

All residues retained

All crop residues removed

  

COVER CROP

ROTATIONS

Lablab years 1& 2

Pigeon peas years

3 and 4 

NoneMaize only

NoneMaize only

Pigeon peas for

years 1&2Lablab for years 3&4

NoneMaize / beans

intercrop

Plot sizes varied from one FFS to another, ranging from 390 - 1440 m2.

Data collected on: rainfall, labour input, soil property changes, maize grain yield and cover crop grain yield.

Recommended crop spacing and use of improved maize seeds were practiced.

Neither industrial nor inorganic fertilizers were used.

Maize Grain Yield (Means for 6 FFS plots)

Each FFS treated as a replication Data analysed using by SAS

programme

No.

Treatment Maize grain yield (kg/ha)2005 2006 2007

1 Jab planter, glyphosate, lablab 1,735 2,889 2,738

2 Ripping, glyphosate, jab, p/peas 1,949 3,018 1,973

3 Jab planter, glyphosate, p/peas 1,770 2,566 1,369

4 Ripping, glyphosate, jab, lablab 2,043 2,357 1,320

5 Farmer’s practice, ox ploughing 1,353 1,502 993

  Grand mean 1,770 2,466 1,679  Annual rainfall

(mm)528 755 988

(532)Source: ARI Selian field data, 2007; Arusha foundation seed farm (some rainfall records).

-

500

1,000

1,500

2,000

2,500

3,000

3,500

YIE

LDS

(kg/

ha)

2005 2006 2007

YEAR

CROP YIELDS DUE TO CA WITH TIME

Jab planter, glyphosate,lablabRipping, glyphosate, jab,p/peasJab planter, glyphosate,p/peas Ripping, glyphosate, jab,lablabFarmers practice, oxploughing

Effect of tillage Ripping with either lablab or pigeon peas

produced significantly different and higher grain yields (of 1,949 & 2,043 kg ha-1 ) vs direct seeding with the jab planter (1,735 &1,770 kg ha-1 ) and conventional ox ploughing (1,353 kg ha-1) during year 1 of CA. 528 mm rainfall

The trend in yield increase differences continued during the second year (755 mm)

Jab planter with lablab & p/peas was highest in year 3 (2,738 kg/ha) followed by ripping (1,973 with lablab and 1,320 kg ha-1 with pigeon peas).

The ox ploughed plots produced the lowest grain yield throughout

Effect of cover crops.

The yield increase trends with time and rainfall variations were consistent for lablab. It produced and maintained the highest yield of 2,738 kg ha-1 in year 3 (in a year with a grand mean of 1,697 kg ha-1) while pigeon peas dropped drastically to 1,320 kg ha-1

Yield variations across sites

Yields across different FFS varied greatly (from a maximum of 7.6 tons/ha in Rhotia Kati for ripper with pigeon peas to 0.2 tons/ha for the farmers’ practice in Getamock), which was understandable due to the differing farmer management skills and the initial degraded status of the fields.

Preferred CA technologies Of the 352 households practicing

66% are women 64% are FFS members 36% are non-FFS members enticed by the

benefits of CA; The preferred planting/tillage

technologies are: the ripper (61%) for FFS members;

complimented by the jab planter for seed placement, or manual

CONCLUSIONS CA increases and stabilise yields with

time and with fluctuations in rainfall compared to conventional ploughing.

Increases in grain yields increase food security.

POINT OF DEPARTURE: Increased yields for smallholders owning small pieces of land (typically 1 ha) does not enable them to eradicate poverty.

Conclusions ..

CA translates to saved time (up to 57% of the growing season) – which might not necessarily translate into meaningful utilisation if opportunity costs are not accessible

What is 2 months of saved time if there is nothing productive to do in the remaining 8 months of the year?

THE WAY FORWARDMake full use of CA based value chains

Walking tractor seeder development

Value addition of oil seeds under CA rotations

Access to equitable markets

ACKNOWLEDGEMENTS

CA SARD was funded by the Government of the Federal Republic

of Germany and implemented by FAO, The Governments of Tanzania and

Kenya. ACT coordinated the project at the Regional Level.

Their support is sincerely acknowledged

THANK YOU

We have the opportunity to make a difference ….

… we, not somebody else …

www.act-africa.org