Balanced Fertilization - Key To Grow Fine Coffee - - EAFCA

Balanced Fertilization
- Key To Grow Fine Coffee -
7th African Fine Coffee Conference & Exhibition
Mombasa, February 11th – 13th 2010
Jürgen Küsters and Dirk Schröder
Hanninghof Research Centre
Yara International ASA, Germany

How to approach a balanced fertilizer
strategy for coffee
1. Know your crop => yield expectation, quality requirements
2. Know your soil => pH, nutrient contents, CEC etc. => soil analysis
3. Optimize growth factors (pH, water, plant protection)
4. Develop a fertilizer strategy
– Which nutrients should be applied and in which form?
– How much nutrients at which time?
5. Monitor the effect of fertilization through soil and leaf analysis
Date: 2010-02-13 Jürgen Küsters © Yara International ASA

Crop knowledge is important:
The effect of nutrients on yield and quality
REF: Yara (Literature Review)
Date: 2010-02-13 Jürgen Küsters © Yara International ASA

Liebig’s barrel illustrates the
Law of the Minimum
Crop yield is limited by the one essential mineral
nutrient that is in the relatively shortest supply.
Jahr => 1985 2005 Veränderung
Ertrag => 58 dt/ha 80 dt/ha + 22 dt/ha
Nährstoffentzüge Korn + Stroh, kg/ha
N 139 192 + 53
P 27 38 + 11
K 87 120 + 33
B
Zn
Mg 13 18 + 5
S 17 24 + 7
Date: 2010-02-13 Jürgen Küsters © Yara International ASA

Lack of one macronutrient reduces yield
of the coffee crop
- Arabica
Yield (kg/ha)
100 %
-15%
-27%
-37%
-93%
REF: Coffee manual - Brazil
Date: 2010-02-13 Jürgen Küsters © Yara International ASA

Sulfur in soils and Yield
- Arabica
Yield (kg/ha)
4000
3500
3000
2500
2000
1500
1000
0 5 10 15 20
Soil S (ppm)
Studies suggest that 10 to 15 ppm SO4-S is adequate.
REF: Malavolta et al. – Brazil, 1987
Date: 2010-02-13 Jürgen Küsters © Yara International ASA

Potassium and Processed Coffee Quality
- Arabica
Polyphenoloxidase activity (U/g)
68
66
64
Very soft quality
Soft quality
62
60
58
56
54
Hard quality
Very hard – acid - poor
0 120 240 480
K fertilizer rate (kg K2O/ha)
REF: de Barros Silva et al. – Brazil, 2002
Date: 2010-02-13 Jürgen Küsters © Yara International ASA

Boron spray and Bean Size
- Robusta
% beans on sieves
Ref: Agriculture and Forestry Scientific Research Institute – Vietnam, 1997
Date: 2010-02-13 Jürgen Küsters © Yara International ASA

Zinc spray - Yield and Bean Weight
- Arabica
%
118
115
112
109
106
103
Leaf Zn (ppm):
Control: 5.6
Spray: 14.5
Optimum leaf standard:
12-30 ppm
100
Control = 100 %
Bean yield
Bean weight
Marketable
yield
REF: Lambot – Burundi, 1989
Date: 2010-02-13 Jürgen Küsters © Yara International ASA

How to approach a balanced fertilizer
strategy for coffee
1. Know your crop => yield expectation, quality requirements
2. Know your soil => pH, nutrient contents, CEC etc. => soil analysis
3. Optimize growth factors (pH, water, plant protection)
4. Develop a fertilizer strategy
– Which nutrients should be applied and in which form?
– How much nutrients at which time?
5. Monitor the effect of fertilization through soil and leaf analysis
Date: 2010-02-13 Jürgen Küsters © Yara International ASA

Nutrient removal by the crop at harvest
- Arabica
Macronutrients (kg/1000 kg green bean)
70
60
50
40
30
20
10
Micronutrients (g/1000 kg green bean)
120
100
80
60
40
20
0
N P2O5 K20 CaO MgO S
0
B Cu Fe Mn Zn
Green bean
Whole berry (equivalent to 1000 kg green bean)
REF: Malavolta – Brazil, 1990
Date: 2010-02-13 Jürgen Küsters © Yara International ASA

Soil pH and nutrient availability
pH of East
African
soils
Optimum
for coffee
Date: 2010-02-13 Jürgen Küsters © Yara International ASA

Nutrient requirements of coffee
in Eastern Africa (generalized)
N, P, Ca, S:
K:
Required, because of low availability in soils and/or high removal
– History of low inputs (N, S)
– P fixation at low pH => efficient (highly soluble) P form or P leaf spray
– Low CEC (Ca), leaching (Ca, N)
Application according to K removal with harvest (soils relatively high in K)
However, if yield expectations and/or quality requirements are high, K may
be required at higher rates
B, Zn:
Required, because of low soil content or low efficiency in soil
Zn leaf spray more efficient than Zn soil application
Mg, Fe, Mn, Cu:
Not required or only in low amounts (high soil content, low removal,
Cu: fungicide spray)
Date: 2010-02-13 Jürgen Küsters © Yara International ASA

Example for a balanced fertilizer strategy
to a coffee crop in Eastern Africa
Key nutrients
N, P, Mg, Ca, S, B, Zn
N, P, K, Ca
N, P, B, Zn
NPK
(each application
@ 150-250 kg/ha)
Calcium nitrate + B
(soil application @
200-300 kg/ha)
20-10-10
or
22-6-12
+Mg+S+B
N, Ca, B
AND/OR
20-10-10
or
22-6-12
+Mg+S+B
20-10-10
or
22-6-12
+Mg+S+B
Foliar spray
P, Mg, S
B, Zn
P, K
B, Zn
Date: 2010-02-13 Jürgen Küsters © Yara International ASA

Thank You !
juergen.kuesters@yara.com
Date: 2010-02-13 Jürgen Küsters © Yara International ASA