ETHIOPIAN DEVELOPMENT RESEARCH INSTITUTE

Digital Soil Mapping: soil fertility status and fertilizer recommendation for Ethiopian

agricultural land

Hailu ShiferawIFPRI-ESSP

Ethiopian Economic Association ConferenceJuly 16, 2014Addis Ababa

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Outline

• Introduction • Objective• Mapping procedure overview: approaches for soil

nutrient prediction • Results found:

– Soil fertility status by nutrients, and– Types of recommended fertilizers

• Further works

BackgroundPlants require many nutrients

(at least 12 types of nutrients)

S, Fe, Zn, and B deficiencies can

limit the response to NP(K)

Deficiencies must be addressed

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Background …

Countries with blending or compound fertilizer plants in Africa

Fertilizer blending is a special type of fertilizer mixing, where blends are prepared by the mechanical mixing of two or more granular materials of fairly uniform size and density in defined proportions. It originated in the USA and now dominates the fertilizer market in many areas.

Often, a farmer has a bulk blend prepared according to the soil test report of the particular farm – a tailor-made, ready-to-use mixture. The main advantages to the farmers are:• Nutrients are supplied in ratios to suit

the needs of particular soils and crops• The cost per unit of plant nutrient is

generally low• The cost of transportation and

spreading is low because of the high analysis of bulk blends.

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Legend:

Existing blending plants and use complex fertilizers

GuineaBissau

NigerChad Sudan

Tunisia

Algeria

Mali

LibyaEgypt

Mauritania

Morocco

Western Sahara

Nigeria

Benin

Togo

BurkinaGhana

Ivory Coast

Guinea

Senegal

Liberia

Sierra Leone

Gambia

Ethiopia

Djibouti

Eritrea

Uganda Somalia

Kenya

CameroonC.A.Republic

Congo

Gabon

Equatorial Guinea

Democratic Rep. of Congo

Tanzania

ZambiaAngola

Mozambique

MadagascarZimbabwe

Botswana

Namibia

SwazilandLesotho

SouthAfrica

Malawi

BurundiRwandaSão Tomé e

Principe

S.Sudan

Comoros

No blending plants, but consume compound fertilizers

Seychelles

Many African countries have already developed fertilizer blending plants; most use Compound fertilizers

EthioSIS workflow, products & services overview

Field obser. data(CU)

NSTC

NATIONAL DATA CENTER BACKUP (PMO)MAIN ETHIOSIS DATABASE (MOA)

Field observ. data

Ethio.ptsSpect data

Ethio.grids

Ethio.outputs

Lab data(Labs across Ethiopia)

WMS/portal

Africa Grids(AfSIS)

Raw Imagery(NASA)

WC data

Lab Data

Tablets in Field

Endusers’ computers

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Legacy Data

Legacy Data8

Today’s talk

Data flowProcessing activityProcessing intensity

• Historical soil information collection in Ethiopia has not been coordinated and didn’t answer the question of status and lack of nutrients at the national level.

• Recommendation of specific fertilizers to increase yield to Ethiopian farmers was not adequately based on knowledge about nutrient status of the agricultural soils

• EthioSIS was launched to provide information on the status of soil fertility of the agricultural lands

Introduction

• So far, EthioSIS has accomplished soil fertility survey in 240 woredas in the country.

• Of these, 35 are woredas in Tigray, thus making Tigray the first region where mapping has been completed.

• By next year this time, the number of woredas for which soil fertility survey has been completed will reach >500.

• By next year this time, Amhara and SNNPRS will also graduate while we only be left with 90 woredas in Oromia, and a few from the emerging Regions.

• So far 12 types of blended fertilizers are found to be deficient

Total by July 2015 = 501 woredas

Introduction

Objective

Specific objectives: • map fertility status of macro and micronutrients for agricultural

areas,• Identify deficient areas of each soil nutrient (macro & micro) by

administrative level.• Produced soil fertility status of Ethiopia that enables the country to

revise its fertilizer advisory services• Develop soil test based-fertilizer recommendations

General Objective: develop digital soil mapping using geo-statistical approach

Methodology; data type & sources

Data types: • Field data (geographic locations)• Wet chemistry and spectral soil data• Covariates (satellite images and other legacy

data)• Land use data (agricultural land)• Admin boundaries

Explanatory Variables (covariates) used for soil nutrient prediction

• Climatic factors: Mean Annual Precipitation (MAP) and Mean Annual Air Temperature (MAT), Land surface temperature of the day and night (LSTd and LSTn);

• Reflectance: Blue, Red, NIR, MIR, BSAn, BSAs, BSAv, WSAn, WSAs, WSAv;

• Topographic: Compound Topographic Index (CTI), elevation, slope and relief; and

• Vegetation indices: EVI, fPAR, LAI, NDVI, NPP.

MODIS & Landsat reflectance & vegetation products

MODIS energy balance (e.g, LST, fPAR, albedo)

WorldClim & TRMM climatologies (e.g, MAP Fournier Index & PET)

SRTM & ASTER terrain models (e.g, elevation, CTI, slope, relief)

Examples of useful remote sensing covariates for digital soil mapping & monitoring

available at: ftp://africagrids.net

Methodology ---modeling approach

• Both Linear and non-linear models were developed: kriging / RK with simulation model

• Using critical values for each soil nutrient • 95% confidence interval • Map resolutions of 1km grid size: we tested 250m for Tigray

• Predicted soil nutrients <- as a function of soil nutrient results from lab and other relevant covariates

Methodology --- Critical level concept

The critical level is the soil test level, below which a crop response to a nutrient application may be expected given that no other nutrient is limiting

Some results

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First draft fertilizer recommendation suggests 54.7% coverage of NPSBZn & 30.3 % of NPSB

First draft fertilizer recommendation suggests 51.11% coverage of NPSBZn & 40.95 % of NPKSBZn

First draft fertilizer recommendation suggests 68.59% coverage of NPSB & 9.40 % of NPS

Fertilizer recommendation map by woreda and Fertilizer formulae

• Combined deficit areas of each nutrients• Identify areas of proportions of each blend (combined

deficit nutrients) Fertilizer types are combined from deficit of macro and micronutrients

• Fertilizer formulas developed by soil experts

• 12 types of blend fertilizers recommended for Ethiopian soil (so far 6 types are unique for Tigray Region)

• These replace DAP, but Urea will be used as additional top dressing fertilizer.

Fertilizer recommendation TypesStandar

d Formula

No.

Fertilizer TypePercent

coverage for Tigray

Remarks

Standard Formula

Modified Blends for Tigray soil

Percent coverage

No.for

Tigray

1 NPS    Not recommended for Tigray but for other

regions 

2 NPSB 7.3

Also recommended for other

Regions

2 NPSB* 7.3

3 NPKSB 10.2 3 NPKSB* 10.2

4 NPSZnB 6.84 & 5

5NPSZnB & NPKSZnB NPKSZnB *

35.4

5 NPKSZnB 28.66, 7 &

127NPSZn, NPKS & NPKSZn

NPKSZn* 3.7

6 NPSZn 1.5

8 & 10 10

NPSFeZn & NPKSFeZn NPKSFeZn*

9.9

7 NPKSZn 1.5

So far, recommended for Tigray Region

9 NPSFeZnB* 3

8 NPSFeZn 8 11 NPKSFeZnB* 28.4

9 NPSFeZnB 3

* these are selected blend types discussed and agreed with regional representatives for implementations on Tigray soil.

10 NPKSFeZn 1.9

11 NPKSFeZnB 28.4

12 NPKS 0.7

Suggested Formulae for blends1. Formula 1 NPS: 19 N – 38 P2O5 +7S2. Formula 2*NPSB: 18 N – 36 P2O5 + 7S + 0.71B (95kg NPS + 4.9 kg Borax)3. Formula 3*NPKSB: 13.7 N – 27.4 P2O5 – 14.4 K2O + 5.1S + 0.54B (72.2Kg NPS + 24.1kg KCl + 3.7kg

Borax) 4. Formula 4 NPSZnB: 17 N – 34 P2O5 + 7S + 2.2Zn + 0.67B (89.9 kg NPS + 5.5 kg ZnSO4 + 4.6 Kg Borax)5. Formula 5*NPKSZnB: 13.0 N – 26.1 P2O5 – 13.7 K2O + 5.6S+ 1.72Zn + 0.51B (68.7kg NPS+22.9 kg KCl

+ 4.9 kg ZnSO4+3.5 kg Borax) 6. Formula 6 NPSZn: 17.7 N – 35.3 P2O5 + 6.5S + 2.5 Zn (92.86kg NPS + 7.14 kg ZnSO4) 7. Formula 7*NPKSZn: 15 N – 31 P2O5 – 8 K2O + 7 S+ 2.2 Zn (81 Kg NPS + 13.5 Kg KCl + 5.5 Kg ZnSO4)8. Formula 8 NPSFeZn: 17 N – 35 P2O5 +8 S+ 0.3 Fe+ 2.2Zn (91.2 Kg NPS + 3.3 Kg Fe-chelate +5.5 Kg

ZnSO4)9. Formula 9*NPSZnFeB: 17 N – 33 P2O5 + 7 S+ 2.2 Zn+ 0.3 Fe+ 0.5 B (87.7 kg /100 kg NPS + 5.5kg/ha

ZnSO4 + 3.3 Fe-chelate +3.5 kg Borax)10. Formula 10*NPKSFeZn: 15 N – 30 P2O5 – 8 K2O +7.0 S+ 0.3 Fe-chelate+ 2.2Zn (77.7 Kg NPS + 13.5 Kg

KCl + 3.3 Fe-chelate +5.5 Kg ZnSO4)11. Formula 11*NPKSFeZnB: 17 N – 20 P2O5 – 8 K2O + 11 S+ 2.2 Zn+ 0.3 Fe + 0.5 B (44.2 Kg DAP + 20 Kg

Urea+ 13.5 Kg KCl +10 Kg Elemental S + 5.5 Kg ZnSO4 + 3.3 Fe-Chelate + 3.5 kg Borax)12. Formula 12NPKS: 15 N – 29 P2O5 – 8 K2O + 10S (56.5 Kg MAP + 20 Kg Urea+ 13.5 Kg KCl+ 10 Kg) * These formulae are discussed and agreed with Tigray Region’s partners to be used for Tigray’s soil .

PROPOSED FERTILIZERS: Diga Woreda - Oromia

Formula 2: 18.1 N – 36.1 P2O5 – 0.0 K2O + 6.7S + 0.00Zn+ 0.71B NPSB(95kg/100kg NPS + 4.9 kg Borax)

Formula 4: 16.9 N – 33.8 P2O5 – 0.0 K2O + 7.3S + 2.23Zn+ 0.67B NPSBZn(86 kg/100kg NPS + 6.4 kg/100kg ZnSO4 + 4.6 Kg/100kg Borax)

Formula 5: 13.0 N – 26.1 P2O5 – 13.7 K2O +5.6S+ 1.72Zn + 0.51B NPKSBZn (68.7kg/100kgNPS+22.9kg/haKCl+4.9kg/haZnSO4+3.56Borax)

The Ethiopian Soil Information System (EthioSIS) team will establish a web mapping portal similar to the one seen below. The portal will allow stakeholders to view and download map data on a large range of soil properties

Data/Map LayersLand Features– Above surface vegetation– Topography– Land Use– Erosion risk (wind and water)Soil Physical properties– Infiltration Capacity– Texture– Bulk DensitySoil Chemical Properties– pH, EC, exchange acidity– CaCO3 content (for high pH soils)

– Soil Organic Carbon– Total nitrogen– Available sulphur, phosphorus– Exchangeable cations (K, Ca, Mg, Na)– CEC– micro-nutrients (Fe, Mn, Cu, Zn, B)- Blend fertilizer maps and recommendations

Eventual EthioSIS output

This list represents the current EthioSIS aspirations; it can grow this list to address a even wider

range of land information for the specific sites of choice

Final web services

Demonstration (site trials) of new fertilizers

Initial observations from 2013 demonstrations: the blended fertilizers are giving significant crop yield

increase as shown in the pictures below

Plot with DAP + Urea only. Planting date 08/05/2013

Maize plot fertilized with blended fertilizer (14 N-21 P2O5-15 K2O + 6.5 S+ 1.2 Zn + 0.5 B.)Planting date 22/05/2013

• Location: SNNPR, Region Soddo TVET College

• Crop: Maize (Shone variety)

• Fertilizer: Blended fertilizer vs. DAP+Urea

• Planting: Blend plot planted two weeks later

Blended fertilizer demonstration

Maize on plot with blend grew faster , greener, wider

leaves and thicker stems than the one with DAP + Urea,

planted 2 weeks earlierSource: Team analysis

This site is already visited by more than 5,000 people

Blended fertilizer demonstration on farmer’s plot in East Wollega, Guto Gida woreda, Demeksa kebele---October 8, 2013

The same tef variety Kuncho planted 15 days earlier as broadcast and with DAP and Urea didn’t perform well compared to the other adjacent plot

Teff variety Kuncho row-planted 15 days later than the adjacent plot and that received blended fertilizer 2 (NPSZn) showed good crop stand with green color

Sample pages of Tigray Soil Fertility Atlas

Sample pages of Tigray Soil Fertility

Sample pages of Woreda Level Soil Fertility

Further works

• Using agricultural land as a base of prediction• Refining the grid size 250 or 500m instead of 1k• Ground level validation works by the research group are

necessary and should be continuous.• About 500 woredas in all regions will be covered by the

end of 2015 so that the result will be refined as more samples are included

• Local productions of blend fertilizers

Fertilizer blending plants

• Five fertilizer blends are to establish locally at four major regions;

• Cooperative unions will operate these plants as a business plant;

• One of the plant has been operated since 1 June 14• 74,000 tons will be produced in 2014, and • By 2017, Ethiopia will produce about 500,000

metric tons of blend fertilizer.

The Fertilizer Blending initiative will make it possible for Ethiopia to locally produce up to 400k tons of blends

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Production (kton)

Tigray, Amhara, Oromia & SNNP

Production should start between June 2014

Construction and equipment are currently being procured

When

Where

Status

The Fertilizer Blending initiative

Capacity 100kton per plant (500k tons total)

Expected production of local plants (ktons)

Already for the first year, a production of 74kton of blended fertilizer is expected

One of the Blending Plant- Becho Wolisoby farmers’ cooperative unions

Innovations to help our country grow