THE POTENTIAL OF CORN
COBS AS SOURCE OF
FERTILIZER FOR WHITE
CORN PRODUCTION
APOLONIO M. OCAMPO
University Researcher III
Institute of Plant Breeding-Crop Science Cluster, College
of Agriculture, UP Los Baños
College, Laguna
OUTLINE:
1. Introduction
2. Objectives
3. Methodology
4. Results and Discussion
5. Conclusion
INTRODUCTION
INTRODUCTION:
White corn is an alternative staple to rice
Corn productivity can be enhanced
through effective use of nutrients from
agricultural waste including corn cobs
Cobs – part of corn ears that is normally
burned in the field or used as cooking
fuel
Incorporation of corn cobs in the soil as
organic fertilizer source of K will mean
substantial savings in inorganic fertilizer
costs for the corn farmer
OBJECTIVES:
a. To identify and evaluate corn cultivars and the
contribution of corn cobs in terms of available
potassium and other nutrient contents
b. To evaluate the effectiveness of corn cobs and
ashes derived from commercial corn dryers and
farmer’s fields when used as soil K-source and
foliar spray
c. determine the period of time required for the K to
be available to plants when applied to the field.
METHODOLOGY
1. Residual Effect of Corn Cobs on Yield
and Fertility Status of the Soil
- 3-season experiment was conducted to
determine the long-term effect of corn
cobs on corn yield, K availability and
other nutrients in the soil (UPLB, CVRC,
NMACLRC)
- cob rates: 0, 5, 10, 15 and 20 tons/ha
- control treatment with inorganic K
fertilizer
- blanket application of 150 N and 90-
120 kg P205/ha
- white corn OPV (IPB Var 6) and hybrid
(Pioneer 30W40)
2. Response of White Corn to K- fertilization
through the application of corn cobs, ash and
inorganic fertilizer source
- the experiment was conducted to
determine the effect of corn cobs and ash on
corn yield and K availability in the soil (UPLB,
CVRC, NMACLRC)
- cobs and ash rates: equivalent amount to
inorganic K source (i.e. 60 kg K/ha)
- control treatment with inorganic K fertilizer
- blanket application of 150 N and 90-120 kg
P205/ha
- white corn OPV (IPB Var 6) and hybrid
(Pioneer 30W40)
3. Corn Cobs as source of Potash
- corn cobs was soaked in water at a
given ratio for a certain period of time to
determine the amount of K in the
solution
- was terminated as soon as the
analysis of K stabilizes
- liquid mixture was used as foliar
spray in a corn pot experiment to
determine the K-fertilizing ability of
this solution
- used OPV (IPB Var 6) and blanket
application of N and P
RESULTS
Table 1. Initial chemical properties of areas used in the experiment.
Soil Properties UPLB
(Tranca,
Bay,
Laguna)
CVRC (San
Felipe, Ilagan,
Isabela)
NMACLRC
(Dalwangan,
Malaybalay,
Bukidnon
pH 6.30 5.90 5.30
Organic Matter, % 2.26 1.05 4.99
Nitrogen, % 0.113 0.053 0.249
Available P, Bray P2, ppm 12.31 17.83 2.24
Exchangeable K, cmol/kg soil 3.33 0.39 0.36
Exchangeable Ca, cmol/kg soil 5.05 6.35 1.86
Exchangeable Mg, cmol/kg soil 5.48 7.32 1.49
Critical levels:
pH – 5.3 Exch. K – 0.40 cmol/kg soil
OM – 4% Exch Ca – 4 cmol/kg soil
Avail P – 15-20 ppm Exch Mg – 0.7 cmol/kg soil
Residual effect of
corn cobs on the
yield of white corn
Table 2a. Mean grain yield of white corn (tons/ha) grown at
different rates of corn cobs at Tranca, Bay, Laguna (UPLB)
during the 2012 DS/WS and 2013 DS cropping (IPB Var 6).
Blanket application of 150 kg N and 90 kg P2O5 per hectare
Fertilized check: 150-90-60 kg N-P2O5-K2O per hectare
Treatments
(tons cobs/ha)
Grain Yield (tons/ha)
2012 DS 2012 WS 2013 DS
Yield Yield
Index
(%)
Yield Yield
Index
(%)
Yield Yield
Index
(%)
0 5.10 g 84.9 4.00 b 77.2 3.33 d 69.1
5 5.42 f 90.2 4.19 b 80.9 3.88 cd 80.5
10 5.64 e 93.8 4.29 b 82.8 4.15 bc 86.1
15 5.73 e 95.3 4.48 ab 86.5 4.38 abc 90.9
20 6.17 c 102.7 4.72 ab 91.1 4.61 ab 95.6
K-fertilized
Check
6.01 c 100.0 5.18 a 100.0 4.82 a 100.0
Unfertilized
Check
- 2.17 c 41.9 1.03 e 21.4
Figure 1. Grain yield of IPB Variety 6 (tons/ha) grown at different rates of corn cobs at Tranca, Bay, Laguna
(UPLB) for 3 cropping periods.
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
T1 T2 T3 T4 T5 T6 T7
Gra
in Y
ield
(to
ns/
ha)
Treatment
1st cropping
2nd cropping
3rd cropping
TREATMENTS
T1: 0 tons cobs/ha
T2: 5 tons cobs/ha
T3: 10 tons cobs/ha
T4: 15 tons cobs/ha
T5: 20 tons cobs/ha
T6: K-fertilized Check
T7: Unfertilized check
Table 2b. Mean grain yield of white corn (tons/ha) grown at
different rates of corn cobs at Tranca, Bay, Laguna (UPLB)
during the 2012 DS/WS and 2013 DS cropping (Pioneer
30W40).
Blanket application of 150 kg N and 90 kg P2O5 per hectare
Fertilized check: 150-90-60 kg N-P2O5-K2O per hectare
Treatments
(tons cobs/ha)
Grain Yield (tons/ha)
2012 DS 2012 WS 2013 DS
Yield Yield
Index (%)
Yield Yield
Index
(%)
Yield Yield
Index
(%)
0 5.78 e 88.5 5.56 c 88.1 4.47 b 83.1
5 5.93 d 90.8 5.78 bc 91.6 4.68 ab 87.0
10 6.13 c 93.9 5.93 abc 94.0 4.84 ab 90.0
15 6.43 b 98.5 6.18 ab 97.9 5.23 a 97.2
20 6.78 a 103.8 6.34 a 100.5 5.29 a 98.3
K-fertilized
Check
6.53 b 100.0 6.31 a 100.0 5.38 a 100.0
Unfertilized
Check
- 3.09 d 49.0 1.27 c 23.6
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
T1 T2 T3 T4 T5 T6 T7
Gra
in Y
ield
(to
ns/
ha)
Treatment
1st cropping
2nd cropping
3rd cropping
Figure 2. Grain yield of Pioneer 30W40 (tons/ha) grown at different rates of corn cobs at Tranca, Bay,
Laguna (UPLB) for 3 cropping periods.
TREATMENTS
T1: 0 tons cobs/ha
T2: 5 tons cobs/ha
T3: 10 tons cobs/ha
T4: 15 tons cobs/ha
T5: 20 tons cobs/ha
T6: K-fertilized Check
T7: Unfertilized check
Table 3a. Mean grain yield of white corn (tons/ha) grown at
different rates of corn cobs at Ilagan, Isabela (CVRC) during
the 2012 DS/WS and 2013 DS cropping (IPB Var 6).
Blanket application of 150 kg N and 90 kg P2O5 per hectare
Fertilized check: 150-90-60 kg N-P2O5-K2O per hectare
Treatments
(tons cobs/ha)
Grain Yield (tons/ha)
2012 DS 2012 WS 2013 DS
Yield Yield
Index (%)
Yield Yield
Index (%)
Yield Yield
Index
(%)
0 5.24 f 92.1 3.50 c 69.9 4.03 d 78.1
5 5.43 ef 95.4 4.09 b 81.6 4.29 cd 83.1
10 5.58 de 98.1 4.21 b 84.0 4.41 bcd 85.5
15 5.73 cd 100.7 4.42 b 88.2 4.65 abc 90.1
20 5.88 c 103.3 5.14 a 102.6 4.98 ab 96.5
K-fertilized
Check
5.69 d 100.0 5.01 a 100.0 5.16 a 100.0
Unfertilized
Check
- 2.45 e 47.5
Figure 3. Grain yield of IPB Variety 6 (tons/ha) grown at different rates of corn cobs at Ilagan, Isabela
(CVRC) for 3 cropping periods.
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
T1 T2 T3 T4 T5 T6 T7
Grain
Yie
ld (
ton
s/h
a)
Treatment
1st cropping
2nd cropping
3rd cropping
TREATMENTS
T1: 0 tons cobs/ha
T2: 5 tons cobs/ha
T3: 10 tons cobs/ha
T4: 15 tons cobs/ha
T5: 20 tons cobs/ha
T6: K-fertilized Check
T7: Unfertilized check
Table 3b. Mean grain yield of white corn (tons/ha) grown at
different rates of corn cobs at Ilagan, Isabela (CVRC) during
the 2012 DS/WS and 2013 DS cropping (Pioneer 30W40).
Blanket application of 150 kg N and 90 kg P2O5 per hectare
Fertilized check: 150-90-60 kg N-P2O5-K2O per hectare
Treatments
(tons cobs/ha)
Grain Yield (tons/ha)
2012 DS 2012 WS 2013 DS
Yield Yield
Index (%)
Yield Yield
Index
(%)
Yield Yield
Index
(%)
0 5.95 c 88.4 4.38 c 83.1 5.30 d 84.4
5 6.23 b 92.6 4.50 c 85.4 5.62 cd 89.5
10 6.39 b 94.9 4.70 bc 89.2 5.78 bcd 92.0
15 6.68 a 99.3 4.91 abc 93.2 5.99 abc 95.4
20 6.89 a 102.4 5.44 a 103.2 6.17 ab 99.3
K-fertilized
Check
6.73 a 100.0 5.27 ab 100.0 6.28 a 100.0
Unfertilized
Check
- 2.99 e 47.6
Figure 4. Grain yield of Pioneer 30W40 (tons/ha) grown at different rates of corn cobs at Ilagan, Isabela
(CVRC) for 3 cropping periods.
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
T1 T2 T3 T4 T5 T6 T7
Grain
Yie
ld (
ton
s/h
a)
Treatment
1st cropping
2nd cropping
3rd cropping
TREATMENTS
T1: 0 tons cobs/ha
T2: 5 tons cobs/ha
T3: 10 tons cobs/ha
T4: 15 tons cobs/ha
T5: 20 tons cobs/ha
T6: K-fertilized Check
T7: Unfertilized check
Table 4a. Mean grain yield of white corn (tons/ha) grown at
different rates of corn cobs at Malaybalay, Bukidnon (NMACLRC)
during the 2012 DS/WS and 2013 DS cropping (IPB Var 6).
Blanket application of 150 kg N and 90 kg P2O5 per hectare Fertilized
check: 150-90-60 kg N-P2O5-K2O per hectare
Treatments
(tons cobs/ha)
Grain Yield (tons/ha)
2012 DS 2012 WS 2013 DS
Yield Yield
Index (%)
Yield Yield
Index (%)
Yield Yield
Index
(%)
0 5.20 g 90.8 3.99 e 74.9 3.86 f 65.0
5 5.33 fg 93.0 4.20 de 78.8 4.01 e 67.5
10 5.51 ef 96.2 4.38 cd 82.2 4.22 d 71.0
15 5.70 de 99.5 4.52 c 84.8 4.41 c 74.2
20 5.79 d 101.1 4.84 b 90.8 4.64 b 78.1
K-fertilized
Check
5.73 d 100.0 5.33 a 100.0 5.94 a 100.0
Unfertilized
Check
- 3.49 g 58.8
Figure 5. Grain yield of IPB Variety 6 (tons/ha) grown at different rates of corn cobs at Malaybalay,
Bukidnon (NOMIARC) for 3 cropping periods.
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
T1 T2 T3 T4 T5 T6 T7
Grain
Yie
ld (
ton
s/h
a)
Treatment
1st cropping
2nd cropping
3rd cropping
TREATMENTS
T1: 0 tons cobs/ha
T2: 5 tons cobs/ha
T3: 10 tons cobs/ha
T4: 15 tons cobs/ha
T5: 20 tons cobs/ha
T6: K-fertilized Check
T7: Unfertilized check
Table 4b. Mean grain yield of white corn (tons/ha) grown at
different rates of corn cobs at Malaybalay, Bukidnon (NMACLRC)
during the 2012 DS/WS and 2013 DS cropping (Pioneer 30W40).
Blanket application of 150 kg N and 90 kg P2O5 per hectare
Fertilized check: 150-90-60 kg N-P2O5-K2O per hectare
Treatments
(tons cobs/ha)
Grain Yield (tons/ha)
2012 DS 2012 WS 2013 DS
Yield Yield
Index
(%)
Yield Yield
Index
(%)
Yield Yield
Index
(%)
0 5.83 d 88.3 4.79 e 76.2 4.70 d 72.6
5 6.11 c 92.6 5.04 d 80.1 5.19 c 80.2
10 6.29 c 95.3 5.21 cd 82.8 5.29 c 81.8
15 6.56 b 99.4 5.39 bc 85.7 5.48 c 84.7
20 6.82 a 103.3 5.60 b 89.0 5.90 b 91.2
K-fertilized
Check
6.60 a 100.0 6.29 a 100.0 6.47 a 100.0
Unfertilized
Check
- 3.97 e 61.4
Figure 6. Grain yield of Pioneer 30W40 (tons/ha) grown at different rates of corn cobs at Malaybalay,
Bukidnon (NOMIARC) for 3 cropping periods.
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
T1 T2 T3 T4 T5 T6 T7
Grain
Yie
ld (
ton
/ha)
Treatment
1st cropping
2nd cropping
3rd cropping
TREATMENTS
T1: 0 tons cobs/ha
T2: 5 tons cobs/ha
T3: 10 tons cobs/ha
T4: 15 tons cobs/ha
T5: 20 tons cobs/ha
T6: K-fertilized Check
T7: Unfertilized check
Corn Cobs-Ash-
Inorganic K
Studies
Table 5a . Comparative analyses of K and N content of
corn cobs taken from different sources
Source % K % N
1. IPB Var 6 (IPB)_cobs 2.44 0.722
2. Lagkitan (IPB)_cobs 1.43 0.497
3. IPB-NSF furnace_ash 28.54 0.174
4. Echague c/o S. Tumamang_cobs 1.11
0.673
5. NABCOR (Jones, Isabela)_cobs
1.38
0.394
6. NABCOR_ash (furnace) 26.46 0.049
7. Villa Luna_ash (furnace) 23.16 0.092
8. Villa Luna_cobs 2.21 0.490
Table 5b . Comparative analyses of K content of corn cobs taken
from different sources
Source % K % N
9. Mindanao Grains_ash (furnace)_Isabela 33.34 0.148
10.Mindanao Grains_cobs_Isabela 1.45 0.376
11.Mindanao Grains_bees wings_Isabela 1.50 1.307
12.Manaring, cobs_Isabela 1.42 0.613
13.CVIARC, ash_(furnace) 28.54 0.006
14.CVIARC_cobs 1.08 0.426
15.Mindanao Grains_cobs_Bukidnon 1.15 0.311
16.Mindanao Grains_ash (furnace)_Bukidnon 21.72 0.035
17.Mindanao Grains_bees wings_Bukidnon 2.73 3.43
18.Mindanao Grains_cobs, partly decomposed file 0.189 1.689
19.NOMIARC_ash 0.170 1.79
Treatments IPB Var 6 Pioneer 30W40
K1_NP-0K 4.21 (81.0) 5.12 (88.1)
K2_NP-cobs 4.87 (93.7) 5.47 (94.1)
K3_NPK 5.20 (100%) 5.81 (100 %)
K4_NP-ash 4.91 (94.4) 5.56 (95.7)
Blanket application of 150 N-90 P2O5
Table 6. Grain yield of white corn grown at different K
source during the 2012 WS cropping at UPLB.
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
T1 T2 T3 T4
Ton
s cob
s/h
a
Treatment
IPB Variety 6
Pioneer 30W40
Figure 7. Grain yield of white corn grown at different K source during the 2012 WS cropping at
UPLB (t/ha).
NP-0K NP-cobs NPK NP-ash
Treatments IPB Var 6 Pioneer 30W40
K1_NP-0K 4.08 (77.1) 5.09 (77.4)
K2_NP-cobs 4.76 (90.0) 5.95 (90.4)
K3_NPK 5.29 (100%) 6.58 (100 %)
K4_NP-ash 4.87 (92.1) 6.11 (92.9)
Unfertilized
check
3.55 (67.1) 4.21 (64.0)
Blanket application of 150 N-90 P2O5
Table 7. Grain yield of white corn grown at different K
source during the 2012 DS cropping at NMACLRC.
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
T1 T2 T3 T4 T5
Ton
s cob
s/h
a
Treatment
IPB Variety 6
Pioneer 30W40
Figure 8. Grain yield of white corn (t/ha) grown at different K source during the 2013 DS
cropping at NOMIARC.
NP-0K NP-cobs NPK NP-ash Unfertilized
control
Treatments IPB Var 6 Pioneer 30W40
K1_NP-0K 3.88 (76.4) 5.72 (87.6)
K2_NP-cobs 4.63 (91.1) 6.60 (101.1)
K3_NPK 5.08 (100%) 6.53 (100 %)
K4_NP-ash 4.66 (91.7) 6.99 (107.0)
Unfertilized
check
2.45 (48.2) 2.99 (45.8)
Blanket application of 150 N-90 P2O5
Table 8. Grain yield of white corn grown at different K
source during the 2012 DS cropping at CVRC.
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
T1 T2 T3 T4 T5
Ton
s cob
s/h
a
Treatment
IPB Variety 6
Pioneer 30W40
Figure 9. Grain yield of white corn (t/ha) grown at different K source during the 2013 DS
cropping at CVRC.
NP-0K NP-cobs NPK NP-ash Unfertilized
control
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
IPB Variety
6
Pioneer
30W40
IPB Variety
6
Pioneer
30W40
IPB Variety
6
Pioneer
30W40
UPLB NOMIARC* CVIARC*
Ton
s cob
s/h
a
K1_ NP-0 K
K2_NP + Cobs
K3_NPK (inorganic fertilizer)
K4_NP + Ash
Unfertilized Control
Figure 10. Grain yield of white corn (t/ha) grown at different K source at different locations.
Table 11. Comparison of K supplied by cobs and ash
equivalent to 60 kg K2O at each site.
Percent K
Content Equivalent no. of bags/kg
Site Ash Cobs Ash Cobs
Mindanao Grains
(Bukidnon) 21.7 1.15
5.5
(276 kg)
104
(5217 kg)
Mindanao Grains
(Isabela) 33.34 1.45
3.6
(180 kg)
83
(4138 kg)
IPB- NSF-UPLB 28.54 2.44
4.2
(210 kg)
49.2
(2459 kg)
CVRC 28.54 1.08
4.2
(210 kg)
111
(5556 kg)
Incubation studies
Cobs rate: 1. 0; 2. 1 t/ha; 3. 5 t/ha; 4. 10 t/ha; 5. 20 t/ha;
6. K-fertilized
Cobs rate: 1. 0; 2. 1 t/ha; 3. 5 t/ha; 4. 10 t/ha; 5. 20 t/ha;
6. K-fertilized (Lipa clay loam)_plant height
Whole cobs Shredded cobs
Finely ground cobs Ashed cobs
Cobs rate: 1. 0; 2. 1 t/ha; 3. 5 t/ha; 4. 10 t/ha; 5. 20 t/ha;
6. K-fertilized (Alipit clay )_plant height
Whole cobs Shredded cobs
Finely ground cobs Ashed cobs
Corn cob extract as
source of potash for
foliar or liquid fertilizer
Figure 11. Potassium content of solution from cobs and ash
soaked in water. 1:25 cobs-water ratio. (1.whole cobs; 2.
shredded cobs; 3. bees wings; 4. shredded cobs; 5. whole
cobs; 7. whole cobs; 8. stocked ash; 9. shredded cobs; 10.
whole cobs)
Treatment
(corn cob:water ratio)
Lipa clay loam Alipit clay
Stovers Roots Stovers Roots
T1 – Control (no fertilizer application) 65.3b 5.2b 146.3c 14.6b
T2 – Inorganic Fertilizer (Recommended Rate) 212.5a 31.8a 251.4a 27.4b
T3 – Liquid Mixture (1:25) 215.4a 29.3a 221.4ab 50.1a
T4 – Liquid Mixture (1:50) 199.1a 24.1a 231.9ab 34.2ab
T5 – Liquid Mixture (1:100) 178.8a 27.5a 187.5bc 25b
T6 – Liquid Mixture (1:250) 185.4a 29.8a 234.3ab 33.3ab
T7 – Liquid Mixture (1:500) 174.9a 25.6a 191.9bc 28.3ab
175.9 24.8 209.2 30.4
Table 12. Effect of spraying of liquid mixture from corn cobs soaked in water
on the fresh biomass of white corn (gm/plant) grown on Lipa clay loam and
Alipit clay soils.
T1_control
T2_Recom
Fert Rate
T3_Liquid
mixture , 1:25
T4_ 1:50
T5_1:100
T6_ 1:250
T7_1:500
Conclusions
and
Recommendations
Corn cob is a promising material as
K source for white corn fertilization
Immediate results for using corn
cobs as K fertilizer source for open
pollinated varieties could be
attained by using 10-15 tons cobs
per hectare while for hybrids, 20
tons per hectare is recommended
Ashed corn cobs from furnace would
give the best results in terms of growth
and biomass production as compared to
whole cobs, shredded cob or finely
ground cobs since it contains higher
amount of K. Extracts from cobs soaked in water could
be used as foliar spray after soaking for
4-5 weeks, however, further studies are
needed to determine the right amount of
dilution and time of application that is
economically feasible
ACKNOWLEDGEMENTS
• Department of Agriculture-Bureau of
Agricultural Research
• Department of Agriculture-AgriPinoy
Corn Program
• PhilMaize Fed. Inc.
• DA-CVRC, Ilagan, Isabela
• DA-NMACLRC, Malaybalay, Bukidnon
• Institute of Plant Breeding-Crop
Science Cluster-College of
Agriculture-UP Los Baños
THANK YOU !!!