Conservation Agriculture for

smallholder farmers in Ethiopia

Melesse Temesgen (PhD)

Agricultural Engineer

Principal Researcher, Aybar Engineering PLC

Mobile: 0911245701

Email: melesse_tem@yahoo.com

The problem

• Conventional tillage causes soil degradation and timeliness problems

• Land degradation:

– loss of soil organic carbon and soil erosion caused by:

– Soil inversion and plowing at high speed.

– Plowing at uniform depth leads to soil erosion and hardpan formation

– plowing up and down the slope accelerates loss of soil and water

The problem (cont’d)

• Timeliness:

– Plowing and harrowing

– Repeated cross plowing with Maresha• V-shaped furrows –unplowed strips of land

• Too much time spent on already plowed soil

• Clods formed through failing soil by pushing with blunt wooden wings necessitates repeated plowing and requires high draft power to prepare fine seedbed

Conservation agriculture• Principles (action based)

– Minimum soil disturbance

– Permanent soil cover

– Crop rotation

• Definition based on practice not objectives.

• Conservation agriculture aims at minimizing:

– loss of soil organic carbon

– Loss of soil moisture

– Soil erosion

– Pests and diseases

– Energy and time requirement

Global distribution of CASoil moisture, soil temperature & power source

Source: Derpsch,R., Friedrich,T., Kassam, A., Hongwen, L. 2010. Current status of adoption

of no-till farming in the world and some of its main benefits. Int J Agric & Biol Eng. Vol. 3 No.1.

Open Access at http://www.ijabe.org

•

Challenges to CA adoption by

smallholder farmers

• Mixed crop-livestock farming – competition for

crop residues

• Shortage of rainfall to maintain soil cover

• Lack of appropriate implements

• Chemical weed control more costly than

manual/animal powered mechanical weed

control (less costly than tractors)

• Adulteration of herbicides

• Health and environmental hazards of Herbicides

(New findings on grain toxicity from Glyphosate)

Is Roundup safe?

• According to Dr Joseph Mercola, in 2009, a French court

found Monsanto guilty of lying; falsely advertising its

Roundup herbicide as "biodegradable," "environmentally

friendly" and claiming it "left the soil clean (Mercola,

2013). In the article it is also stated “You'd also be wise

to stop using Roundup around your home, where

children and pets can come into contact with it simply by

walking across the area.”

Mercola, J. 2013. Monsanto’s Roundup Herbicide May Be

Most Important Factor in Development of Autism and

Other Chronic Disease. Available online:

http://articles.mercola.com/sites/articles/archive/2013/06/

09/monsanto-roundup-herbicide.aspx

CA for smallholder farmers

• Identify root causes of soil degradation

• Other African countries: Use of moldboard plows

that invert, pulverize and smear the soil

• Ethiopia: Use of Maresha, which creates V

shaped furrows with unplowed strips of land and

which produces too many clods, forces farmers

to carry out repeated cross plowing.

• Result: Loss of soil organic carbon, formation of

plow pans, loss of water through surface runoff

and evaporation, soil erosion and low biomass

production

Problems with Maresha plowing

• Creates V-shaped furrows with

unplowed strips of land

• Too much time spent by plowing

already plowed land in search of

missed strips

Problems with Maresha plowing

•Plowing up and down the slope

•Increased flow momentum (high

surface runoff and soil erosion)

•Too low and too high rake angles of

plow while plowing up and down,

respectively.

•Strenuous and energy demanding

Problems with Maresha plowing

(cont’d)Difficult to plow fields with soil conservation

structures due to short turning distance

Poor distribution of water within a terrace leads to either

waterlogging at lower part or dry soils at the upper part in

addition to risking bund failure and accelerated erosion

Problems with Maresha plowing

(cont’d)• Opens up the soil leading to

higher evaporation and loss of soil

organic carbon.

• High draft power requirement due

to cutting with blunt wooden wings

• Long travel distance of soil along

wooden wings increases draft

forces.

• Failing soil by pushing results in

clod formation due to failure along

slip lines. More plowing is needed

to reduce clod size.

Why urge farmers to reduce

plowing while using Maresha?• No farmer would like to waste time and

energy on repeated plowing.

• The solution: we have to provide them with

an efficient tool that minimizes tillage

• We have identified the root causes of

repeated plowing with Maresha

• The next step is to come up with

something that removes those root causes

Silet Deger

.

Attached to the traditional plow,

Maresha, replaces the Deger

• Makes use of soil mechanics principles

• Designed to cut soil deep at the center &

shallow on the sides over a span of 36cm

• Integrates ripping with weeding

Advantages of Silet Deger

• Cup shaped furrow

– Disrupt plow pan at the center for increased

infiltration and root growth

– Shallow cutting on the sides to kill weeds

– Possibility of CA without Glyphosate

• Reduced costs, reliability, reduced risk on health

and the environment.

– Formation of invisible barriers that mimic the

actions of soil conservation structures

Advantages of Silet Deger

(Cont’d)• Wings designed for efficient soil cutting

– Reduced draft power requirement

– Reduced clod formation

• Reduced soil inversion

– Moisture conservation through reduction of

soil evaporation (soil mulching)

– Reduced loss of soil organic carbon

– Reduced draft power requirement

• Reduced deforestation

Advantages of Silet Deger (Cont’d)

• Avoids cross plowing

– Reduced energy and time requirement

– Reduced surface runoff (improved soil

moisture availability)

– Reduced soil erosion

– Convenient plowing between soil

conservation structures

– Reduced tillage frequency

– Improved timeliness of operation and/or

increased cultivable land

– Reduced cattle population

Test results

• Soil cutting performance (Sululta, Oromia, 2015)

Parameter Maresha Arashogel

Mean furrow depth (cm) 11 16

Average minimum depth (cm) 0 9

Invisible barrier height (cm) - 7

Max depth (cm) 14 19

Implement

Soil profile before and after plowing

• .

0

5

10

15

20

25

30

35

40

0 50 100 150 200 250 300

Silet Deger Before plowing

After plowing

0

5

10

15

20

25

30

35

40

0 50 100 150 200 250 300 350

MareshaBefore plowing

After plowing

Silet Deger penetrated deeper with complete plowing

in one pass while leaving invisible barriers to retard

runoff and reduce soil erosion

Effects on surface runoff and

soil loss

Effect of tillage method on surface runoff and soil loss (Bolo Sellase, Minjar,

Amhara RS, 2013). Laike Kebede et al.Unpublished data

slope (%) TT CT % reduction TT CT % reduction

3 8.1 3.00 63.0 2.46 0.87 64.7

8 22.4 9.70 56.7 12.52 3.30 73.7

14 29.6 15.30 48.3 14.26 3.72 73.9

TT=Maresha, CT= Arashogel

soil loss Surface runoff coefficient (%)

Effect of CT with Silet Deger on

crop yields

• Nine farmers participated in an on-farm trial in

Semen Achefer, Bahrdar Zuria and Gonder zuria

districts of Amhara region

• Crop yields increased in all sites with a

maximum increment of 100% in wheat yield

(Mastewal Melkamu, Agronomist, BoA of Semen

Achefer) and Tef and Sorghum (Melke Belay,

Agronomist, BoA of Gondor Zuria woreda)

Waterlogging in vertisols

• Vertisols are fine textured soils with poor

drainage resulting in seasonal waterlogging

(water stagnation on the surface)

• 7.6 million hectares of vertisols in Ethiopia suffer

from waterlogging problems

• Farmers can effectively cultivate only 1.9Mill ha

• Plowing until September to plant chickpea leads

to soil erosion and emission of CO2

• Seasonal waterlogging leads to production and

emission of NH4 (20 times more potent than CO2

as GHG)

Construction of BBF to drain

excess water in vertisols

• Farmers rejected earlier

models because of high

draft force, heaviness, poor

performance, etc

• Aybar BBM addressed all

complaints of farmers

• Crop yields increased by

upto 300%

• Broad bed and furrows (BBF) constructed

at planting can drain excess water

• Development of appropriate BBF maker

(BBM) started in 1984.

Reversing the role of water from emission

of GHG to carbon sequestration

• Drainage allows early planting, which replaces

CO2 emission from plowing by carbon

sequestration from live crops in addition to

reducing soil erosion and generating additional

income to farmers

• Drainage reduces production and emission of

NH4

• Drained excess water stored in ponds is used to

irrigate a 3rd crop thereby extending soil cover by

live crops

.

Thank you