Development of a Potassium (K) module to be
incorporated into Nutrient Management
Support System for major West African soils
SM-CRSP
IFS
IER
Adama BAGAYOKO
WEST AFRICAN SOILS CONSTRAINTS
P and N deficiencies
Soil
Sotuba
Charact. (Mali)
Clay (%)
3
OM (%)
0.48
pH (KCl)
4.9
Total N
142
(mg.kg-1)
Total P
87
(mg.kg-1)
Bray 1 P
1.7
(mg.kg-1)
Bambey
(Sénégal)
3.1
0.36
4.9
180
Sadoré
(Niger)
1
0.22
4.1
74
-
68
-
6.9
SM-CRSP
Source
ADSC
UH
POTASSIUM (K) DEFICIENCY
Preliminary results of Nioro-Senegal
Number of
sample
farmers
52
A.N’diaye
Means exchangeable
K mg/kg
10.6
48
T. Sene
7.0
50
O. kane
2.6
60
C .Wilane
0.1
56
A. Toure
7.5
46
M. Diabo
8.8
50
C. Ba
3.7
POTASSIUM (K) DEFICIENCY
Preliminary results cotton zone in Mali
Moro-Moro
Sambala
Bendougou
Farabale
Source
LaboSEP
IER
DokolonTamaro
Tigangoni
Sanankoro
Goro
Togo
Toba
Ouroun
Tagan
Karakara
Ntobougou
KaciensoTintine
Nadiasso
Mpetiala
Kome
Doma1
Nafrola
Nangola B Ntosso
Katogo
Sinsing1
Ntjila
Faboula
Djine
Denderesso
Farako
Yorotiena
Foulabala
Kambo
Sirakoro
Figure1. Spatial distribution of
exchangeable K in cotton zones
in Mali
Mackuy
Figure 2. Name of site cotton
zones in Mali
HYPOTHESIS
SM-CRSP
IFS
IER
The continuous cropping systems,
without K fertilization deplete the K
reserve of most West African soils.
Therefore, K applications on these
soils become necessary to increase
soil nutrient status and sustain or
increase crop yields.
OBJECTIVES
 The overall objective is to develop K specific
recommendations for key stable food crops in West
Africa
 Specifics objectives:
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IFS
IER
1. To develop and compare a K module to accurately
predict K fertilizer requirements,
2. To determine economic benefit.
METHODOLOGY
 Soil
collection : Cinzana Landform
(Toposequence)
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IER
Soil label CZ1
CZ2
CZ3
CZ4
 Soil analysis
 Incubation
CZ5
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IER
RESULTS AND DISCUSSION
Malian soils results
Soil Name
Mineralozy
Texture (%)
Clay
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IER
sand
Loam
Cinzana 1
Quartz, kaolinite
4
92
4
Cinzana 2
Quartz, kaolinite
3
93
4
Cinzana 3
Quartz, kaolinite
5
88
7
Cinzana 4
Quartz, kaolinite
14
81
5
Cinzana 5
Quartz, kaolinite
36
54
10
Soil pH Cinzana Topsoil
7
6
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5
4
pH(water)
3
2
1
0
CZ 1
CZ 2
CZ3
CZ4
CZ5
Extractable and Exchangeable K (mg/kg) Cinzana Topsoil
160
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IFS
IER
140
120
100
80
ExtractableK
Echangeable K
60
40
20
0
CZ 1 CZ 2 CZ 3 CZ 4 CZ 5
Total and Extractable K (mg/kg) Cinzana Topsoil, Mali
3000
2500
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2000
Total K
Extractable K
1500
1000
500
0
CZ 1 CZ 2 CZ 3 CZ 4 CZ 5
INCUBATION RESULTS
Figure 4.Cinzana soil 1
Figure 5. Cinzana Soil 2
Exchnageable K (mg/kg)
60
50
y = 11,268x - 9,07
40
R = 0,7249
2
30
20
10
0
0 KCl
9,1 KCl
27,3 KCl
81,8 KCl
60
50
y = 8,94x - 1,806
2
40
R = 0,8371
30
20
10
0
245,5 KCl
0 KCl
9,1 KCl
K added (mg/kg)
81,8 KCl
245,5 KCl
Figure 7. Cinzana Soil 4
Exchangeable K (mg/kg)
100
y = 10,22x + 24,866
80
27,3 KCl
K added (mg/kg)
Figure 6. Cinzana Soil 3
Exchangeable K (mg/kg)
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K echangeable (mg/kg)
70
2
R = 0,8056
60
40
20
0
70
60
y = 11,64x - 8,078
50
R = 0,8003
2
40
30
20
10
0
0 KCl
9,1 KCl
27,3 KCl
81,8 KCl
K added (mg/kg)
245,5 KCl
0 KCl
9,1 KCl
27,3 KCl
81,8 KCl 245,5 KCl
K added (mg/kg)
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CONCLUSION
 Potassium levels are low
Future research
 K Buffer coefficient
Development of a potassium (K) module
THANKS
SM-CRSP
Soil Management Collaborative Research
Support Program
Sponsors
TPSS
Department of Tropical Plant and Soil Science
University Hawaii at Manoa
IFS
International Foundation for Science, Sweden