Evaluate: Performance N, P and K uptake and use efficiency Residual soil nutrients after cropping Tuber storability of white yam grown with different levels of organo-mineral fertilizers. Evaluate soil N, P and K content over time in sole yam cropping system

1. Response of white yam (Dioscorea
rotundata Poir.) to different levels of
organo-mineral fertilizers at Ikenne
and Ibadan, southwest Nigeria
Lawal O. Isiaq

2. Introduction
• Yams (Dioscorea spp.) are important
staple food crop widely cultivated in
West Africa, Southeast Asia and the
Caribbean.
• The poor tuber yields are attributable to
declining soil fertility & inability of
farmers to use inorganic fertilizers.
• It therefore becomes exigent to source
for cheaper alternatives to inorganic
fertilizers. 2

3. • Several studies have shown that yams respond
well to application of organic fertilizers
• Combined use of organic and inorganic fertilizers
in crop production is more beneficial than single
use
• Combination of organic and inorganic inputs that
allows 50% cost reduction is one option validated
through the Balanced Nutrient Management
Systems project
• Dearth of information exists on the use of
compost with or without NPK fertilizer on yam
production vis-à-vis the detailed composition of
manure and the environmental conditions of the
area where the results were obtained. 3

4. Objectives
Evaluate:
 Performance
 N, P and K uptake and use efficiency
 Residual soil nutrients after cropping
 Tuber storability
of white yam grown with different levels
of organo-mineral fertilizers.
 Evaluate soil N, P and K content over
time in sole yam cropping system
4

5. Materials and Methods
• Field trials were conducted at Ikenne (Longitude
3o 42’E and Latitude 6o 54’N) and Ibadan
(longitude 3o 54’E and latitude 7o 30’N) in 2004
and 2005.
• Pre-cropping soil and organic fertilizers used
were chemically analyzed to determine nutrient
contents.
 Organic fertilizer Grade B (Composted cowdung
plus sorted city refuse): Pacesetter Fertilizer
Company, Bodija, Ibadan
 Chemical fertilizer N. P. K. 12-12-12 (150 Kg/ha,
300 Kg/ha and 450 kg /ha) was formulated from
urea, triple superphosphate and muriate of
potash.
5

6. • Experimental design was a split plot arranged
in randomized complete block X 4 reps.
• Four white yam land races (Cultivar ‘Adaka’,
‘Amula’, ‘Danacha’ and ‘Omiefun ) were used
as test crop.
• Yam setts (60 g) were planted for each of 2
seasons at a spacing of 1 m X 0.5 m, 25 m2 plot
size (50 plants/plot)
 Fertilizer treatments (Table 1) were applied one
month after shoot emergence in grooves 10-15
cm from the base of each plant
6

7. • Data Analysis
• GLM procedure of SAS (Version 9.1) was
used to determine ANOVA
• Significant treatment means were
separated using the Duncan Multiple
Range Test or the least significant
difference (LSD) at 5% level of significant.
7

8. Table 1: N P K contents of the fertilizer materials
Treatments N P K
(Kg/ha)
1) No fertilizer (control) 0 0 0
2) 2.5 t/ha Organic Fertilizer 32 13 32
3) 5.0 t/ha Organic Fertilizer 64 26 64
4) 150 kg/ha NPK12-12-12 18 18 18
5) 300 kg/ha NPK12-12-12 36 36 36
6) 450 kg/haNPK12-12-12 54 54 54
7) 1.75 t/haOF+150 kg/ha NPK 32 23 36
8) 2.5 t/haOF+150 kg/ha NPK 56 31 56
9) 2.5 t/haOF+300 kg/ha NPK 64 49 68
8
10) 5.0 t/haOF+300Kg/haNPK 96 62 98

9. Table 2. Pre-planting soil chemical and physical properties
in the experimental sites in 2004 and 2005
2004 2005
Soil Properties Ikenne Ibadan Ikenne Ibadan
pH (H2O)(1:1) 5.7 5.5 5.9 6.0
PH (KCl) (1:1) 4.1 5.0 4.7 5.4
Nitrogen (g/Kg) 1.58 0.87 1.08 1.06
Phosphorus (Mg/Kg) 15.7 6.18 8.43 16.36
Potassium (Cmol/Kg) 0.38 0.17 0.15 0.28
Calcium (Cmol/Kg) 1.47 1.65 4.81 1.82
Magnesium (Cmol/Kg) 0.32 1.50 1.05 0.45
Sodium (Cmol/Kg) 0.34 0.16 0.08 0.12
Organic carbon 0.67 0.38 0.62 0.35
CEC 3.68 2.92 3.68 2.92
Sand (%) 74 78 73 76
Silt (%) 10 10 10 11
Clay (%) 16 12 17 13
Classification (USDA 1994) Typic Oxic Kandiustalf Typic paleudalfs Oxic
paleudalfs Sandy loam Sandy loam 9
Kandiustalf
Sandy loam Sandy loam

10. Table 3: chemical properties of Organic fertilizer
Nitrogen (%) 1.09
Phosphorus (%) 0.70
Potassium (%) 1.27
Calcium (%) 0.48
Magnesium (%) 3.06
Sodium (%) 0.75
Iron (mgkg-1) 95.00
Copper (mgkg-1) 39.45
Zinc (mgkg-1) 286
Manganese (mgkg-1) 330
10

11. • Expt. 1: Estimation of growth and yield of
white yam grown with different levels of
organo- mineral fertilizer
• Data Collection:
• Length of vines, number of leaves, number of
vine branches and dry matter accumulation at
monthly interval on 5 sample plants/plot;
• leaf area index estimated;
• Tuber weight estimated at harvest
11

12. RESULTS:- EXPT: Growth parameters
180.00
IKENNE IBADAN No fertilizer
160.00 2.5t/haOF
5.0t/haOF
Vine length (cm)
150Kg/haNPK
140.00 300Kg/haNPK
450Kg/haNPK
1.75tha-1OF+150kgha-1NPK
120.00 2.5tha-1OF+150kgha-1NPK
2.5tha-1OF+300kgha-1NPK
5.0tha-1OF+300kgha-1NPK
100.00
80.00
60.00
4 8 12 16 4 8 12 16
Weeks after fertilizer application
Fig. 1: Effect of different levels of organic based fertilizers on
vine length of four clones of white yam in Ikenne and Ibadan
2004
12

13. 180.00
IKENNE IBADAN No fertilizer
2.5t/haOF
160.00 5.0t/haOF
150Kg/haNPK
140.00 300Kg/haNPK
Number of leaves
450Kg/haNPK
120.00 1.75tha-1OF+150kgha-1NPK
2.5tha-1OF+150kgha-1NPK
2.5tha-1OF+300kgha-1NPK
100.00
5.0tha-1OF+300kgha-1NPK
80.00
60.00
40.00
20.00
4 8 12 16 4 8 12 16
Weeks after fertilizer application
Fig. 3: Effect of different levels of organic based fertilizers on
Number of leaves of four cultivars of white yam at Ikenne and
Ibadan 2004
13

14. 2.70
IKENNE IBADAN
No fertilizer
2.5t/haOF
2.65 5.0t/haOF
150Kg/haNPK
300Kg/haNPK
Leaf area index
450Kg/haNPK
1.75tha-1OF+150kgha-1NPK
2.60 2.5tha-1OF+150kgha-1NPK
2.5tha-1OF+300kgha-1NPK
5.0tha-1OF+300kgha-1NPK
2.55
2.50
2.45
4 8 12 16 4 8 12 16
Weeks after fertilizer application
Fig. 5: Effect of different levels of organo-mineral fertilizers
on leaf area index of four cultivars of white yam at Ikenne
14
and Ibadan 2004

15. Table 3: Effect of different levels of organo-mineral fertilizers on tuber yield
of four cultivars of white yam at Ikenne and Ibadan 2004 and 2005
Tuber yield (t /ha)
2004 2005
Fertilizer treatments Ikenne Ibadan Ikenne Ibadan
No fertilizer 18.46ab 8.21d 8.08e 10.58d
2.5tha-1OF 19.88ab 10.06cd 9.36de 11.38cd
5.0tha-1 OF 22.60a 10.95bc 12.37bc 13.26bc
150kgha-1NPK 12-12-12 20.69ab 10.68bc 11.88cd 12.31bcd
300kgha-1NPK 12-12-12 21.31a 11.36bc 12.53bc 14.14b
450kgha-1NPK12-12-12 19.20a 15.91a 17.34a 19.84a
1.75tha-1OF+150kgha-1NPK 19.14ab 10.94bc 12.24bc 14.11b
2.5tha-1OF+150kgha-1NPK 20.58a 11.86bc 16.60b 17.94ab
2.5tha-1OF+300kgha-1NPK 21.65a 13.46ab 17.94a 20.43a
5.0tha-1OF+300kgha-1NPK 21.98a 15.97a 18.22a 20.72a
15
Means in the column followed by the same letters are not significantly different at 5% level by DMRT

16. Table4: Relative tuber yield of fertilized white yam plots over the unfertilized
(control)
2004 2005
%Incre %Increa %Increa %Increa
Fertilizer treatments ase se se se
Ikenne /control Ibadan /control Ikenne /control Ibadan /control
- -
No fertilizer 18.46 - 8.21 - 8.08 10.58
2.5tha-1OF 19.88 7.8 10.06 22.4 9.36 15.8 11.38 16.6
5.0tha-1 OF 22.60 22.6 10.95 33.42 12.37 52.54 13.26 28.93
150kgha-1NPK 12-12-12 20.69 12.2 10.03 30.2 11.88 47.0 12.31 16.7
300kgha-1NPK 12-12-12 21.31 15.4 11.36 38.5 12.53 55.0 14.14 33.7
450kgha-1NPK12-12-12 19.20 25.8 15.91 94.2 17.34 14.9 19.84 87.9
1.75tha-1OF+150kgha-1NPK 19.14 3.7 10.94 33.2 12.84 58.9 14.11 33.7
2.5tha-1OF+150kgha-1NPK 20.58 11.5 11.86 44.9 16.60 118.8 17.94 29.2
2.5tha-1OF+300kgha-1NPK 21.65 17.4 13.46 64.4 17.94 121.7 20.43 16
93.6
5.0tha-1OF+300kgha-1NPK 21.98 29.9 15.97 94.6 18.22 125.8 20.72 96.2

17. Table 5: Ikenne 2004 Yield: Cultivar X fertilizer interaction
Fertilizer
Fertilizer Adaka Amula Danacha Omiefun means
No fertilizer 17.20 15.05 16.88 14.95 16.02
2.5tha-1OF 20.55 20.75 15.20 23.00 19.88
5.0tha-1 OF 23.45 21.00 19.65 26.30 22.60
150kgha-1NPK 12-12-12 14.10 23.30 15.90 29.45 20.69
300kgha-1NPK 12-12-12 21.45 22.20 19.05 22.55 21.31
450kgha-1NPK12-12-12 19.95 22.50 14.75 19.60 19.20
1.75tha-1OF+150kgha-1NPK 16.50 23.25 18.15 18.65 19.14
2.5tha-1OF+150kgha-1NPK 20.60 24.20 17.80 19.70 20.58
2.5tha-1OF+300kgha-1NPK 22.00 20.65 23.95 20.00 21.65
5.0tha-1OF+300kgha-1NPK 21.25 22.40 17.00 19.25 19.98
Variety means 19.71 21.53 17.83 21.35
SE ± F-test
Cultivar 1.11 Cultivar 0.0717 NS
Fertilizer 1.76 Fertilizer 0.4075 NS
17
Cultivar*fertilizer 0.8536 NS

18. Table 6: Ibadan 2004 yield: Cultivar X fertilizer interaction
Fertilizer Treatments Fertilizer
Adaka Amula Danacha Omiefun means
No fertilizer 8.20 9.60 7.35 8.68 8.46
2.5tha-1OF 6.90 7.25 10.05 8.90 8.28
5.0tha-1 OF 11.90 11.70 10.70 8.70 11.75
150kgha-1NPK 12-12-12 13.60 8.20 5.85 13.85 10.38
300kgha-1NPK 12-12-12 11.60 14.75 11.00 8.10 11.36
450kgha-1NPK12-12-12 10.00 11.50 11.90 14.80 12.05
1.75tha-1OF+150kgha-1NPK 8.85 8.70 11.75 13.20 10.63
2.5tha-1OF+150kgha-1NPK 8.80 11.15 7.10 10.80 11.46
2.5tha-1OF+300kgha-1NPK 11.70 11.45 12.96 10.35 12.61
5.0tha-1OF+300kgha-1NPK 10.80 12.78 11.20 9.95 11.98
Variety means 10.24 10.71 9.99 10.73
SE± F-test
Cultivar 0.59 Cultivar 0.7645 NS
Fertilizer 0.94 Fertilizer 0.0561 *
Cult. X Fert. 0.1443 18
NS

19. • Expt. 2: Evaluation of N, P and K uptake and use
efficiency of white yam plants grown with different
levels of organic- based fertilizers
Nutrient uptake = nutrient conc. (g) X Dry matter
• The fertilizer NUE was estimated according to the
procedure by Moll et al, 1982.
-NUE = Tuber yield / Native + fertilizer N
-Where NUE = Nutrient use efficiency in gkg-1.
• same procedure was also used to calculate P and
K use efficiency.
19

20. 60.00 IKENNE IBADAN
50.00 No fertilizer
2.5t/haOF
N uptake (g/plant)
5.0t/haOF
40.00 150kg/haNPK
300kg/haNPK
450kg/haNPK
1.75t/haOF+150kg/haNPK
30.00 2.5t/haOF+150kg/haNPK
2.5t/haOF+300kg/haNPK
5.0t/haOF+300kg/haNPK
20.00
10.00
0.00
4 8 12 16
4 8 12 16
Weeks after fertilizer application
Fig. 9: Effect of different levels of organo-mineral fertilizer on nitrogen
uptake of four cultivars of white yam at Ikenne and Ibadan 2004
20

21. No fertilizer
IKENNE IBADAN 2.5t/haOF
14.00 5.0t/haOF
150kg/haNPK
12.00 300kg/haNPK
P uptake (g/plant)
450kg/haNPK
1.75t/haOF+150kg/haNPK
10.00 2.5t/haOF+150kg/haNPK
2.5t/haOF+300kg/haNPK
8.00 5.0t/haOF+300kg/haNPK
6.00
4.00
2.00
0.00
4 8 12 16 4 8 12 16
Weeks after fertilizer application
Fig. 11: Effect of different levels of organo-mineral fertilizer on Phosphorus
uptake of four cultivars of white yam at Ikenne and Ibadan 2004
21

22. IKENNE IBADAN
No fertilizer
80.00 2.5t/haOF
5.0t/haOF
K uptake (g/plant)
70.00 150kg/haNPK
300kg/haNPK
60.00 450kg/haNPK
1.75t/haOF+150kg/haNPK
50.00 2.5t/haOF+150kg/haNPK
2.5t/haOF+300kg/haNPK
40.00 5.0t/haOF+300kg/haNPK
30.00
20.00
10.00
0.00
4 8 12 16 4 8 12 16
Weeks after fertilizer application
Fig. 9: Effect of different levels of organo-mineral fertilizer on Potassium
uptake of four cultivars of white yam at Ikenne and Ibadan 2004
22

23. Table 7: Effect of different levels of organo-mineral fertilizers on Nutrient
use efficiency of four white yam cultivars in Ikenne and Ibadan 2004.
Nutrient use efficiency (g/kg)
IKENNE 2004 IBADAN 2004
Fertilizer Treatments N P K N P K
No Fertilizer 29.82 29.44 34.37 26.75 36.69 25.75
2.5t/haOrganic Fertilizer 14.75 17.25 15.31 6.38 10.63 6.44
5.0t/haOrganic Fertilizer 9.75 13.63 8.69 4.75 8.38 4.13
150Kg/ha NPK12-12-12 26.31 15.31 28.25 13.75 10.69 14.31
300Kg/ha NPK12-12-12 14.19 10.50 14.63 7.69 6.88 7.81
450Kg/haNPK12-12-12 8.69 6.88 8.88 4.69 4.38 4.81
1.75t/haOF+150Kg/haNPK 14.31 12.31 13.25 8.06 9.00 7.31
2.5t/haOF+150Kg/haNPK 9.00 11.06 10.31 4.13 6.38 4.75
2.5t/haOF+300Kg/haNPK 8.31 8.38 8.06 4.31 5.00 3.94
5.0t/haOF+300Kg/haNPK 5.38 6.50 5.00 2.44 3.25 2.25
SE 4.77 1.48 4.58 8.10 1.34 4.40
23

24. • Expt. 3: Evaluation of Soil mineral N, P and K
content in yam cropping system.
• Soil samples (ten cores per sub-plot) taken at 0-30
cm depth at monthly intervals were processed using
the procedure described by Murphy and Riley
(1962), Vander paauw et al., (1971) and Inskeep and
Bloom (1984). The amount (Y) of Mineral N, P or K
in Kg/ha was calculated using the formular:
• Y = C * T * BD * D * 10
DW
Where C = mineral N (NO3-N and NH4-N), P or K
concentration in (µg/g)
T = total amount of extract used (cm3),
BD = bulk density of soil in the profile (Kgm-3)
24

25. D = depth of soil sampled (m),
DW = oven dried weight of soil sample (g) and
10 = conversion factor to kg/ha.
The summation of NO3-N and NH4-N content will give
the available soil mineral N. Mineral P and K content
was also be determined by calculation.
Residual soil nutrients after the cropping of yams was
also determined thus:
• Ten core per plot were taken around the spots where
yam tubers were harvested,
• These were bulked together processed and taken to
laboratory for Physico-chemical analyses for essential
nutrients.
25

26. No fertilizer
IKENNE IBADAN 2.5t/haOF
110 5.0t/haOF
150kg/haNPK
100 300kg/haNPK
450kg/haNPK
90 1.75t/haOF+150kg/haNPK
2.5t/haOF+150kg/haNPK
Soil N (kg/ha)
80 2.5t/haOF+300kg/haNPK
5.0t/haOF+300kg/haNPK
70
60
50
40
30
20
4 8 12 16
4 8 12 16
Weeks after fertilizer application
Fig. 11: Effect of different levels of organo-mineral fertilizers on soil nitrogen content
in soils over time in yam based cropping system at Ikenne and Ibadan 2004.
26

27. Table10: Effect of different levels of organo-mineral fertilizers on
residual effect of nutrients on soil after cultivation of white yam in
Ikenne 2004
Ikenne 2004 Residual Soil Nutrient
Fertilizer Treatment pH( Org.C N P K Ca Mg Na Fe Zn
H2O)
% Mg/kg Cmol/kg Mg/kg
Pre-planting 5.70 0.67 0.14 10.70 0.38 1.47 0.32 0.34 69.9 0.83
No fertilizer 5.76 1.02 0.12 11.18 0.20 2.07 0.50 0.19 117.65 1.02
2.5tha-1OF 5.78 1.23 0.16 16.98 0.46 1.79 0.53 0.17 109.79 1.63
5.0tha-1 OF 5.80 1.41 0.37 19.46 0.65 2.14 0.51 0.28 147.01 1.95
150kgha-1NPK 12-12-12 5.78 1.35 0.17 19.39 0.17 1.90 0.48 0.28 128.56 1.99
300kgha-1NPK 12-12-12 5.79 1.37 0.18 22.70 0.24 2.43 0.84 0.22 122.14 1.02
450kgha-1NPK12-12-12 5.74 1.24 0.17 17.81 0.17 2.10 0.51 0.20 129.06 2.65
1.75tha-1OF+150kgha-1NPK 5.76 1.33 0.19 20.06 0.29 2.20 0.57 0.23 157.37 2.52
2.5tha-1OF+150kgha-1NPK 5.80 2.26 0.27 32.35 0.41 2.11 0.51 0.19 163.30 2.86
2.5tha-1OF+300kgha-1NPK 5.89 3.36 0.29 35.67 0.51 2.47 0.58 0.23 175.52 1.47
5.0tha-1OF+300kgha-1NPK 5.88 4.41 0.39 24.48 0.76 2.25 0.53 0.21 146.07 1.87
SE ± 0.05 0.05 0.01 3.32 0.02 0.14 0.04 0.02 14.21 27 1.07

28. Table 11: Effect of different levels of organo-mineral fertilizers on
residual effect of nutrients on soil after cultivation of white yam in Ibadan
2004
Ibadan 2004 Residual Soil Nutrient
pH(
Fertilizer Treatment H20) Org. N P K Ca Mg Na Fe Zn
C
% Mg/kg Cmol/kg Mg/kg
Pre-planting 5.00 0.38 0.17 0.17 0.17 1.65 1.50 0.16 60.10 0.57
No fertilizer 6.17 1.40 0.23 10.15 0.14 4.13 1.35 0.23 441.01 4.40
2.5tha-1OF 6.15 2.97 0.21 12.96 0.35 3.74 1.16 0.17 453.41 4.82
5.0tha-1 OF 6.23 4.15 0.22 13.80 0.58 4.02 1.27 0.24 428.75 3.56
150kgha-1NPK 12-12-12 6.12 2.01 0.22 9.88 0.17 3.89 1.17 0.30 431.40 4.34
300kgha-1NPK 12-12-12 6.45 2.36 0.24 10.66 0.21 4.71 1.32 0.35 378.04 2.91
450kgha-1NPK12-12-12 6.40 2.22 0.22 11.53 0.15 4.65 1.32 0.27 394.37 3.43
1.75tha-1OF+150kgha-1NPK 6.10 2.04 0.24 12.68 0.30 4.09 1.58 0.29 372.84 3.47
2.5tha-1OF+150kgha-1NPK 5.95 3.90 0.22 12.89 0.46 3.95 1.27 0.24 423.11 3.11
2.5tha-1OF+300kgha-1NPK 6.54 4.20 0.23 16.59 0.69 5.03 1.31 0.22 430.83 3.89
5.0tha-1OF+300kgha-1NPK 6.08 5.12 0.22 18.63 0.85 3.92 1.25 0.20 447.46 4.30
28
SE ± 0.13 0.11 0.01 2.92 0.02 0.23 0.06 0.04 19.82 0.30

29. • Expt. 4: Evaluation of Shelf life of yam tubers
from plants treated with organo-mineral
fertilizers
• Six healthy tubers from each plots were
selected, bagged, tagged and weighed.
• These were put in rectangular plastic basket
and kept on the shelves of the yam barn for
data collection
• initial weight of tubers before and during
storage were measured.
29

30. Table 12: Effect of different levels of organic based fertilizers on weight
loss of four cloness of white yam in Ikenne 2004
Fertilizer treatments Initial Wt 4WAS* 16WAS
(kg) Wt (kg) Wtloss(%) Wt (kg) Wtloss(%)
No fertilizer 4.85 4.61 4.81 2.94 18.88
2.5tha-1OF 5.33 5.05 5.18 3.16 19.33
5.0tha-1 OF 5.44 5.16 4.91 3.23 19.17
150kgha-1NPK 12-12-12 5.43 5.15 5.02 3.23 18.95
300kgha-1NPK 12-12-12 5.89 5.61 4.72 3.56 19.24
450kgha-1NPK12-12-12 5.10 4.84 5.14 3.03 19.19
1.75tha-1OF+150kgha-1NPK 5.38 5.11 5.01 3.12 19.60
2.5tha-1OF+150kgha-1NPK 5.33 5.06 4.98 3.10 19.73
2.5tha-1OF+300kgha-1NPK 5.46 5.20 4.85 3.34 18.19
5.0tha-1OF+300kgha-1NPK 5.28 5.02 4.90 3.10 20.28
SE ± 0.46 0.44 0.14 0.27 0.51
30

31. Summary & Conclusion
 Of all the treatment combinations; Organo-mineral
fertilizers at 5.0t/ha OF + 300kg/ha NPK gave the best
performance followed by 2.5t/haOF + 300 kg/ha NPK,
then 450 kg/ha NPK and 5.0 t/ha OF.
 Although nutrient uptake and crop performance
increases with increase fert. rate; 5.0t/ha OF +
300kg/ha NPK, 2.5t/haOF +300kgNPK and 2.5t/haOF
+150kgNPK gave similar result.
 NPK use efficiency decreases with increasing fertilizer
rates. Thus plots with no fertilization had the highest
NPK use efficiency.
31

32. Soil NPK contents decreases with advancing
age of plant and increases latter towards
harvesting.
Residual soil nutrients in experimental plots
increases with increasing organic matter
content of fertilizer materials.
Storage assessment of yam tubers indicated
no significant difference in tubers grown with
the different fertilizer materials.
.
32

33. Acknowledgements
• Almighty ALLAH
• My profound gratitude to my supervisors:
• Prof. G.0. Adeoye
• Dr Robert Asiedu (IITA)
• IITA Yam breeding Unit Staff.
• IARSAF-IITA
• Family and friends
33

34. 34