Soil nutrient status and okra pod yield
as influenced by plant density and cow
dung manure application
Law-Ogbomo, K.E., Osaigbovo, A.U.
and Ogedegbe, S.A.
INTRODUCTION
• Crop productivity (soil nutrient and plant
density)
• Impoverished tropical soils (Akanbi and
Togun,2002)
• Inorganic vs. Organic fertilizers
(Aiyelaagbe,2011; Idachaba, 2004)
• Plant density affects yield (Weiner,1990;
Gupta et al., 2004)
Objectives of the study
Effects of cow dung and plant density on
1) soil nutrient status
2) pod yield of okra
In a degraded soil in humid rain forest zone (Edo
State, Nigeria)
Materials and Methods
Two-year field study at University of Benin
Research farm
Two factors (Cow dung and Plant density)
Cow dung (0, 300,450 kg /ha )
Plant density (47619, 66666, 83333 pph)
Soil analysis (Pre-sowing and post-harvest)
based on Mylavarapus and Kennelley (2002)
method.
Materials and Methods contd.
3 x 3 factorial in RCBD replicated three times
Plots were 2 m x 1.5 m in size
Okra cultivar (NHAc-47-4)
Okra seeds were cold water treated for 12 hrs before
sowing
Weed and pest control carried out as required
Okra pods harvested thrice
Data combined for analysis using Genstat, 2005
Means separated with LSD at 5 % level of probability
Table 1 :Physical and chemical properties of the soil
prior to cropping with okra
Soil properties
Sand (g /kg)
Silt (g /kg)
Clay (g/kg)
pH (water)
Organic carbon (%)
Total nitrogen (%)
Available P (mg /kg)
Exchangeable cation (cmol /kg)
Ca
Mg
Na
K
Ca/Mg
*Ibude et al.(1988)
Value
790.00
30.00
180.00
4.80
0.95
0.07
19.90
2.69
1.17
0.59
0.37
5.36
Critical Level*
1.16
0.15
8.50
1.50
0.28
0.16
3.00
Table 3 : Soil properties after cow dung application
prior to cropping with okra
Cow dung (kg/ha N) pH(water) Organic C (%) Total N (%)
0
4.82
0.95
0.07
300
5.50
1.27
0.10
450
5.56
1.36
0.10
LSD(0.05)
0.560
0.173
0.013
Cow dung (kg/ha N)
0
300
450
LSD(0.05)
Exchangeable cations (cmol kg-1)
Ca
Mg
Na
2.69
1.17
0.56
4.55
1.96
0.63
4.69
2.00
0.61
1.227
0.716
0.039
Available P (mg /kg)
19.90
27.60
22.10
7.370
K
0.37
1.00
1.07
0.383
Table 4a : The effect of cow dung application on soil
chemical properties after cropping with okra
Cow dung (kg/ha N) pH(water) Organic C (%) Total N (%)
0
4.81
0.68
0.05
300
6.99
0.78
0.06
450
7.19
0.84
0.07
LSD(0.05)
0.484
NS
0.019
Cow dung (kg/ha N)
0
300
450
LSD(0.05)
Exchangeable cations (cmol kg-1)
Ca
Mg
Na
1.98
0.59
0.22
1.87
0.64
0.28
2.10
0.86
0.27
NS
NS
NS
Available P (mg /kg)
12.51
17.53
13.88
4.634
K
0.1
0.12
0.07
NS
Table 4b : The effect of plant density on soil chemical
properties after cropping with okra
Plant density (pph)
47619
66666
83333
LSD(0.05)
pH(water) Organic C (%) Total N (%)
7.04
0.84
0.07
6.73
0.81
0.06
6.61
0.64
0.07
NS
NS
NS
Plant density (pph)
47619
66666
83333
LSD(0.05)
Ca
1.82
2.25
1.88
NS
Exchangeable cations (cmol kg-1)
Mg
Na
0.83
0.26
0.67
0.28
0.64
0.27
NS
NS
Available P (mg /kg)
6.85
19.37
17.69
4.634
K
0.08
0.13
0.08
NS
Table 5:Effects of plant density and cow dung application
on pod yield of okra
Cow dung (kg/ha N)
0
300
450
LSD(0.05)
Plant density (pph)
47617
66666
83333
LSD (0.05)
LSD (0.05) CD X PD
Pod yield
g/ stand
t/ha
9.78
0.60
32.36
2.05
33.05
2.11
2.308
0.113
30.92
24.03
20.24
2.308
3.998
1.47
1.60
1.69
0.113
0.195
Table 6: Interactive effects of plant density and cow dung
application on pod yield of okra
Plant density(pph) Cow dung (kg/ha N)
47619
0
300
450
66666
0
300
450
83333
0
300
450
LSD (0.05) Plant density x cow dung
Pod yield
g/stand
t/ha
13.51
0.64
39.97
1.90
39.97
1.97
8.95
0.60
30.70
2.05
32.45
2.16
6.88
0.57
26.40
2.20
27.44
2.29
3.998
0.20
Discussion
Soil test results indicated low native fertility
Cow dung had appreciable nutrient content
which improved soil properties (Besho and
Bell,1992)
Pod yield reduced with higher plant density
Pod yield increased with cow dung application
and higher plant density
Conclusion
Okra produced optimum yield when grown with cow
dung application (300 kg/ ha N) and plant
population (83333 pph)