thesis presentation

1. EFFECT OF NITROGEN FERTILIZER APPLICATION RATES AND
CUTTING HEIGHT ON MORPHOLOGICAL CHARACTERISTICS,
YIELD, AND NUTRITIVE VALUE OF ELEPHANT GRASS AT MERSA
COLLEGE OF AGRICULTURE, NORTHERN ETHIOPIA
BY
HUSSEN EBRAHIM
(Bsc. IN ANIMAL RANGELAND AND WILDLIFE SCIENCES)
A THESIS SUBMITTED TO THE DEPARTMENT OF ANIMAL PRODUCTION AND
TECHNOLOGY, COLLEGE OF AGRICULTURE, SCHOOL OF GRADUATE
STUDIES
WOLDIA UNIVERSITY, MERSA, ETHIOPIA
A THESIS SUBMITTED TO THE GRADUATE SCHOOL IN PARTIAL
FULFILLMENT FOR THE AWARD OF MASTER OF SCIENCE DEGREE OF
WOLDIA UNIVERSITY (SPECIALIZATION: ANIMAL NUTRITION)
JUNE, 2019

2. PRESENTATION OUTLINES
1.INTRODUCTION
2.MATERIALS AND METHODS
3.RESULTS AND DISCUSSION
4.CONCLUSIONS AND RECOMMENDATIONS
5.ACKNOWLEDGEMENTS

3. 1. INTRODUCTION
 The sector contributes:-
 15-17% to national GDP,
 35-40% to agricultural GDP,
 37 to 87% of the household
income
 Supports the livelihoods of
70% of the total population
 Generating 11-20% of
annual export earnings
(Guthiga et al., 2017).
 80% of farmers use for crop
production (Behnke and
Fitaweke, 2011).
Figure 1. Livestock population in Ethiopia (Source; CSA, 2018)

4. INTRODUCTION (CONT’D)
Huge livestock + Low productivity
o 1.37 and 3.91 liters of
milk per day from a cow
and camel, respectively.
o 66, 221.8 tons of honey
per year and
o 136.8 millions of egg per
year (CSA, 2018).
56%
30%
0%
14%
Figure 2. Challenges of Animal Production

5. INTRODUCTION (CONT’D)
Elephant grass Variability of on-farm yields
o Application of fertilizer
o Cutting management
o Soil fertility,
o Disease and pest,
o Variety and planting method,
o Weed control, and
o Lack of knowledge
High yield
Cultivated both in the dry and wet
seasons of Ethiopia
Ease of propagation,
Resistant to disease and drought,
Ability to adapt everywhere,
Water use efficiency and
Ability to use CO2
Figure 3. Elephant Grass At Mersa

6. INTRODUCTION (CONT’D)
Elephant Grass
Nitrogen Fertilizer
The grass removed 183 kg
N/ha/year (Na et al., 2014)
200-600 kg N/ha increased herbage
(30-50%) (Singh et al., 2013)
Determine cost and biomass
Cutting Height
Sparse Information
Affect re-growth
Low crude protein and
digestibility (Jørgensen et
al., 2010).

7. INTRODUCTION (CONT’D)
 Even though little information is known about the separate effect of N
fertilizer as well as cutting height, the combined effects to elephant grass
production and chemical composition are not well understood.
 Therefore, investigation of the optimal nitrogen fertilizer and cutting
height is needed since there was no available data in the study area.
General Objective of the Study
 To evaluate the application of nitrogen fertilizer and cutting height on
morphological characteristics, yield, and nutritive value of elephant grass
(Pennisetum purpureum).
Specific objectives of the Study
 To evaluate the main effect of nitrogen fertilizer rates and cutting
heights and their combined effects on morphological characteristics,
yield, and nutritive value of elephant grass.
 To determine the partial budget analysis of nitrogen application rate on
the yield of elephant grass.

8. 2. MATERIALS AND METHODS
2.1. Description of the Experimental Area
 Established at Mersa;-
o 11°40′N-11°66.7′N latitude
o 39°39.5′E- 39°65′E longitude
o Altitude of 1600 MASL
o Located 491 km North-East of
Addis Ababa
o Bimodal rain fall (650-700 mm)
o Average annual T0 (210C)
Figure 4. Map of the Experimental Area
Soil analysis
 Nine soil samples of 300 kg
were collected
 Then, the composite soil
sample was dried and analyzed
 PH (6.7),
 Total N content (0.0168%),
 Organic matter content(0.9482%)
 Organic carbon (0.55%)
 Electrical conductivity (0.054
ds/m)
 Phosphorous (22.6 ppm).

9. 2.2. Source of Planting Material, Experimental Design and
Treatments
 The source of stems was Mersa
 The experiment was a 4*3
factorial arrangement in RCBD
with three replications.
o Four rates of nitrogen fertilizer 0,
69, 115, and 161 kg/ha
o Three cutting heights of 7.5, 15,
and 22.5 cm
o Total area =19.4m*43.9m (851.66
m2).
o Block size=5m*41.5m (207.5 m2)
o The plot size =5 m*3 m (15 m2)
o Net plot area= 3m*2m (6 m2)
Figure 5. The Experimental Field Laid Out Design
Treatment Combinations
T1 7.5*0
T2 7.5*69
T3 7.5*115
T4 7.5*161
T5 15*0
T6 15*69
T7 15*115
T8 15*161
T9 22.5*0
T10 22.5*69
T11 22.5*115
T12 22.5*161

10. 2.3. Land Preparation, Planting and Management Practices
 The required land was plowed
 One thousand eighty pits were
prepared
 The parent plants cut into
stems with three nodes
 Treatment plots were fertilized
with N
 Weed control
 Supplemented with irrigation
 No phosphorous (P) was used
based on the soil test.
Figure 6. The Land Preparation, stem
cutting, planting and weed management

11. 2.4. Data Collection
2.4.1. Growth characteristics
 All samples were taken from
the net plot area
 Plant survival rate
 Tillers per plant
 Plant circumference
 Fresh and dry weight per tiller
 Plant height
 Leaf number
 Leaf length
 Leaf width
 Tiller number
 The number of nodes per plant
 Internodes length
 The tiller diameter
Figure 7. Measurement of Growth Characteristics
Were taken
from 5
representative
plants

12. 2.4.2. Green forage, dry matter yield and leaf to Stem determination
Figure 8. Sample Preparation

13. 2.4.3. Chemical analysis
 The representative plant
samples drawn for DM
determination were analyzed:-
 Ash contents (AOAC, 1990)
 Nitrogen content (AOAC, 1995)
 NDF, ADF, and ADL contents
(Van Soest et al.,1991)
 Organic matter =100-ash
 The total CP yield=CP * TDMY
2.5. Data Analysis
 The data were subjected to the
GLM (SAS, 2004).
 Treatment means were
separated using Tukey HSD
test
 The ANOVA model for data
analysis consisted of the
effects of N fertilizer, cutting
height and their interaction.
 The model used for the
analysis was:
Yijl = μ + Bl + Fi + Cj + FCij + eijl
Figure 9. Nutritive Value Analysis of elephant grass

14. 2.6. Partial Budget Analysis
 Partial budget analysis was assessed by the variable costs of
fertilizer and labor (Upton,1979).
 The sale price was estimated using local market observations.
 The difference in the sale and purchase of all inputs was
considered as a total return (TR).
 NR= TR-TVC
 ∆NR=∆TR-∆TVC
 MRR = ∆NR/∆TVC*100

15. 3. RESULTS AND DISCUSSION
Table 1. Effects of Cutting Height, Rate of N Fertilizer and their Interaction on Plant Survival
Rate, Number of Tillers, Weight per Tiller and Tiller Diameter of Elephant Grass.
Cutti
ng
height
SUR TN TW TD
7.5 73.33 30.75c 106.72a 1.98
15 76.94 33.75b 102.26b 1.92
22.5 78.33 37.75a 91.8c 2.18
P<0.05 0.0912 <.0001 <.0001 0.2066
SEM 1.578 0.333 1.097 0.104
N
rates
SUR TN TW TD
0 67.78c 24.67d 114.13a 1.81
69 90.74a 31.33c 102.66b 1.94
115 78.52b 38.67b 98.77b 2.07
161 67.78c 41.67a 85.48c 2.27
P<0.05 <.0001 <.0001 <.0001 0.0782
SEM 1.822 0.385 1.267 0.12
Treat
ments
SUR TN TW TD
T1 66.67 21g 109.45b 2.27abcd
T2 86.67 30ef 93.01cd 2.67ab
T3 73.33 35cd 122.29a 1.57cde
T4 66.67 37c 102.12bc 1.40de
T5 70.00 24g 109.95b 1.53cde
T6 91.11 31ef 131.24a 1.13e
T7 78.89 38c 81.25e 2.53abc
T8 67.78 42b 86.61de 2.47abcd
T9 66.67 29f 122.98a 1.63bcde
T10 94.44 33de 83.74de 2.40abcd
T11 83.33 43ab 92.79cd 1.73bcde
T12 68.89 46a 67.69f 2.93a
P<0.05 0.7098 0.0041 <.0001 <.0001
SEM 3.155 0.667 2.195 0.208
CV% 7.17 3.388 3.791 17.823
 The lowest survival rate was recorded at the N application rate of 0 and 161 kg/ha, which
might be due to the fact that the inhibition of plant growth caused by excessive use of N
fertilizer (Sant’Ana et al., 2018) and competition for moisture in higher N fertilizer rate.
 The effect nitrogen on the number of tiller was higher than cutting height that might be due
to the higher nutrient synthesis and reserve in the stem of the plant at the higher N fertilizer
application that might promote more tiller production per plant.
 Tiller weight decreased as the cutting height increased which might be attributed to the
higher tiller density per plant that tended to have thinner stems in easier tillers. Weight of a
tiller decreased with an increase in N fertilizer and was in agreement with IICA (2016)
 Similar to the current study, Stida et al. (2018) reported that the tiller diameter increased at
the increasing dose of N fertilizer but it did not differ statistically.
 Generally, TN was similar to stida et al. (2018) but TD was opposed to Olivera et al. (2015)

16. Table 2. Effects of Cutting Height, the Rate of Nitrogen Fertilizer and their Interaction on
Plant Height, Internode Length, Leaf Length and Leaf Number.
PH INL LL LN
Cutting Height (cm)
7.5 1.53c 18.6 55.0c 10.65c
15 1.84b 18.43 60.0b 11.95b
22.5 2.03a 17.84 64.50a 13.0a
P<0.05 <.0001 0.2691 <.0001 <.0001
SEM 0.007 0.334 0.782 0.102
The Rate of Nitrogen Fertilizer (kg N/ha)
0 0.95d 13.88c 46.33c 8.07d
69 1.5c 17.22b 53.33b 10.6c
115 2.23b 21.36a 68.33a 13.93b
161 2.5a 20.69a 71.33a 14.87a
P<0.05 <.0001 <.0001 <.0001 <.0001
SEM 0.008 0.385 0.903 0.118
Cutting Height*Nitrogen Fertilizer Rates
(cm*kg N/ha)
Trea. PH INL LL LN
T1 0.8l 14.30c 45h 7.2i
T2 1.3i 16.00bc 50gh 10fg
T3 1.9f 20.90a 61def 12.2e
T4 2.1e 20.17a 64cde 13.2de
T5 0.95k 14.00c 46h 8hi
T6 1.5h 16.33bc 53fgh 10.8f
T7 2.3d 21.70a 69bcd 14cd
T8 2.6b 21.67a 72abc 15bc
T9 1.1j 13.33c 48h 9gh
T10 1.7g 19.33ab 57efg 11f
T11 2.5c 21.47a 75ab 15.6ab
T12 2.81a 20.23a 78a 16.4a
P<0.05 <.0001 0.0305 0.0224 0.0001
SEM 0.013 0.667 1.563 0.204
CV% 1.277 6.318 4.526 2.981
 The degree of influence of plant height is more with N fertilizer rate than cutting height,
which could be due to the reason that the grass was sensitive to the application of N-
fertilizer (Na et al., 2014) than the effect of cutting height.
 The leaf length in the present study was in agreement with Ojo et al. (2015) and Rambau et
al. (2016), who reported 49.33 to 68 cm.
 In line with the result of the present study, Ojo et al. (2015), Wangchuk et al. (2015), and
Rambau et al. (2016) found a positive response of leaves per tiller with an increased rate of
N fertilizer application.
 Generally, PH was inline with IICA (2016) and Stida et al. (2018) but INL was contrary to
Mamaru (2018) LL and LN was similar to Ojo et al. (2015) and Rambau et al. (2016).

17. Table 3. Effects of Cutting Height, the Rate of Nitrogen Fertilizer and their Interaction on
Leaf width, Number of Internodes, and Plant Circumference of Elephant Grass.
LW NN PC
Cutting Height (cm)
7.5 1.93c 7.79c 117.3c
15 2.15b 9.0b 126.325b
22.5 2.45a 9.85a 135.45a
P<0.05 <.0001 <.0001 <.0001
SEM 0.035 0.116 1.236
The Rate of Nitrogen Fertilizer (kg
N/ha)
0 1.13c 6.11d 99.8d
69 2.17b 8.21c 118.87c
115 2.63a 9.8b 139.67b
161 2.77a 11.4a 147.1a
P<0.05 <.0001 <.0001 <.0001
SEM 0.04 0.135 1.427
Cutting Height*Nitrogen Fertilizer
Rates (cm*kg N/ha)
LW NN PC
T1 0.8 5.33h 90.4
T2 2 7.63ef 114
T3 2.4 8.40e 129
T4 2.5 9.80d 135.8
T5 1.1 6.00gh 101
T6 2.2 8.60e 119.3
T7 2.6 10.00cd 140
T8 2.7 11.40b 145
T9 1.5 7.00fg 108
T10 2.3 8.40e 123.3
T11 2.9 11.00bc 150
T12 3.1 13.00a 160.5
P<0.05 0.1487 0.0008 0.1060
SEM 0.07 0.233 2.472
CV% 5.531 4.542 3.388
 Elephant grass harvested at a higher cutting height and fertilized with higher N showed
wider leaves, which could be explained by its’ faster regrowth as the result of higher
availability of carbohydrate reserve in the stems of the grass.
 The highest internodes per tiller was at the highest cutting height and the rate of N fertilizer.
This could be because of the fastest growth in higher cutting height and N fertilizer rates.
 Generally, LW and PC was similar to Oliveira et al. (2015) and Wangchuk et al. (2015) but
NN was opposed to Tessema et al. (2010b).

18. Table 4. Effect of Cutting Heights, Rates of Nitrogen Fertilizer and their Interaction on
Green Forage, Dry Matter and Crude Protein Yield of Elephant Grass.
GFY TDMY TCPY
Cutting Height (cm)
7.5 21.46b 3.53b 0.47c
15 30.38a 4.85a 0.66a
22.5 31.75a 4.7a 0.59b
P<0.05 <.0001 <.0001 <.0001
SEM 0.659 0.125 0.013
The Rate of Nitrogen Fertilizer (kg
N/ha)
0 17.56d 2.73c 0.35c
69 26.51c 4.29b 0.6b
115 31.24b 5.09a 0.68a
161 36.13a 5.34a 0.67a
P<0.05 <.0001 <.0001 <.0001
SEM 0.761 0.144 0.014
Cutting Height*Nitrogen Fertilizer Rates
(cm*kg N/ha)
GFY TDMY TCPY
T1 17.28f 2.45c 0.29d
T2 20.94def 2.98c 0.35d
T3 22.50def 4.36b 0.63b
T4 25.11cde 4.33b 0.61b
T5 18.61ef 2.80c 0.35d
T6 27.22cd 5.51ab 0.95a
T7 34.19b 4.65b 0.53bc
T8 41.50a 6.45a 0.82a
T9 16.83f 2.95c 0.43cd
T10 31.37bc 4.38b 0.51bc
T11 37.03ab 6.25a 0.87a
T12 41.79a 5.24ab 0.58b
P<0.05 <.0001 <.0001 0.025
SEM 1.318 0.25 0.0201
CV% 8.195 9.93 6.161
 The higher GFY and TDMY could be associated with higher tiller number, total
nonstructural carbohydrate (Wadi et al., 2004) and plant height (Obok et al, 2012).
 The reduction in DMY of elephant grass from the 7.5 cm cutting height was 27.22%
compared with the 15 cm cutting height (Table 4.3), which could be attributed to larger
leaves attached to the plant cut at a 15 cm (Jørgensen et al., 2010) and this was also
reported by Geren et al. (2016).
 The application of a higher rate of N fertilizer resulted in double GFY and TDMY over the
control group (Table 4.3), which could be attributed to the higher number of tillers along
with the taller grass (Ansah et al., 2010).
 15 cm*69 kg N/ha produced 3.4 times higher TCPY than 7.5 cm*0 kg N/ha that could
have happened because of higher leaf content at harvest from the grass fertilized with 69
kg N/ha when cutting at 15 cm above the soil surface.
 Generally, GFY and TDMY was similar to Geren et al. (2016), Ayal (2017) and Oliveira et
al. (2015) but TCPY was contrary to Tessema et al. (2010b).

19. Table 5. Effect of Cutting Heights, Rates of Nitrogen Fertilizer and their Interaction on Leaf,
and Stem Dry Matter Yield and Leaf:Stem Ratio of Elephant Grass (continued).
LDMY SDMY LSR
Cutting Height (cm)
7.5 1.78b 1.75c 0.99b
15 2.63a 2.23b 1.2a
22.5 2.21a 2.47a 0.9c
P<0.05 <.0001 <.0001 <.0001
SEM 0.067 0.061 0.001
The Rate of Nitrogen Fertilizer (Kg
N/ha)
0 1.38c 1.36d 1.02b
69 2.28b 1.98c 1.13a
115 2.59a 2.49b 1.04b
161 2.57ab 2.78a 0.92c
P<0.05 <.0001 <.0001 <.0001
SEM 0.077 0.07 0.01
Cutting Height*Nitrogen Fertilizer
Rates (cm*Kg N/ha)
LDMY SDMY LSR
T1 1.23e 1.23e 0.97
T2 1.57de 1.37e 1.10
T3 2.20cd 2.17cd 1.00
T4 2.10cd 2.23c 0.90
T5 1.53de 1.27e 1.20
T6 3.10ab 2.40bc 1.30
T7 2.57bc 2.10cd 1.23
T8 3.30a 3.17a 1.07
T9 1.37e 1.57de 0.90
T10 2.17cd 2.17cd 1.00
T11 3.00ab 3.20a 0.90
T12 2.30c 2.93ab 0.80
P<0.05 <.0001 <.0001 0.3153
SEM 0.134 0.122 0.016
CV% 10.511 9.792 2.758
 The results in the current experiment were within the range reported in the works of Tessema (2008),
Ansah et al. (2010) and Mamaru (2018), who reported mean values ranging from 0.64 to 13.3 tons
DM/ha/cut for leaf and 0.76 to 7.03 tons DM/ha/cut for stem when harvested at a stump of 5-15 cm.
 The current result also agreed with those of Figueira et al. (2016), who noted the significant
effect of cutting heights (30-60 cm) on the leaf to stem ratio with a mean value ranging from
1.07 to 1.36 for elephant grass cultivated in Brazil.
 Generally, LDMY and SDMY was similar to Oliveira et al. (2015) and LSR was inline with
Figueira et al. (2016)

20. Table 6. Effect of Cutting Heights and Rates of Nitrogen Fertilizer on the Nutritive Contents (% for
DM and % DM for others) of Elephant GrassH.E. Thesis DocumentHUSSEN FINAL
THESISnutritive value of Elephant grass.docx
DM CP OM Ash NDF ADF ADL
Cutting Height (cm)
7.5 16.16a 13.59b 86.48b 13.52b 55.03c 42.16b 10.5
15 16.04a 14.02a 86.94a 13.07c 57.39b 44.21ab 10.68
22.5 15.09b 13.27c 83.74c 16.26a 59.3a 46.23a 10.69
P<0.05 <.0001 <.0001 <.0001 <.0001 <.0001 0.0011 0.5910
SEM 0.063 0.07 0.087 0.873 0.372 0.552 0.145
The Rate of Nitrogen Fertilizer (kg N/ha)
0 15.48c 13.31b 86.83a 13.17c 56.77b 45.12a 10.71ab
69 16.11b 14.11a 83.29c 16.71a 60.74a 46.49a 10.92a
115 16.45a 13.88a 86.12b 13.88b 56.97b 44.27a 10.74ab
161 15.01d 13.19b 86.63a 13.37c 54.48c 40.91b 10.1b
P<0.05 <.0001 <.0001 <.0001 <.0001 <.0001 0.0005 0.0249
SEM 0.073 0.081 0.101 0.101 0.43 0.638 0.167

21. Table 6. Effect of Cutting Heights, Rates of Nitrogen Fertilizer and their interaction on the Nutritive
Contents (% for DM and % DM for others) of Elephant Grass (continued).
Cutting Height*Nitrogen Fertilizer Rates (cm* kg N/ha)
DM CP OM Ash NDF ADF ADL
T1 14.02 12.34de 87.1bc 12.9de 60.56bc 48.23ab 12.17a
T2 14.19 12.30de 86.17cd 13.83cd 58.06cd 45.72abc 10.54ab
T3 19.25 15.00b 86.02de 13.98bc 57.51cde 43.45bc 10.63ab
T4 17.17 14.72b 86.625bcd 13.375cde 44.01f 31.23d 8.64c
T5 14.98 12.88cd 86.17cd 13.83cd 53.80e 41.39c 9.95bc
T6 20.20 17.86a 88.17a 11.83f 55.42de 42.90bc 10.09bc
T7 13.56 11.93ef 87.23ab 12.77ef 57.44cde 44.68abc 11.06ab
T8 15.43 13.40c 86.17cd 13.83cd 62.90b 47.88ab 11.6ab
T9 17.46 14.72b 87.23ab 12.77ef 55.95de 45.75abc 10.02bc
T10 13.93 12.19def 75.53f 24.47a 68.75a 50.87a 12.14a
T11 16.56 14.72b 85.11e 14.89b 55.95de 44.68abc 10.54ab
T12 12.43 11.45f 87.1bc 12.9de 56.54cde 43.62bc 10.05bc
P<0.05 0.126 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001
SEM 0.0611 0.14 0.175 0.175 0.744 1.105 0.29
CV% 1.13 1.45 0.288 1.73 1.838 3.535 3.862
 The grass harvested at a cutting height of 7.5 cm and 15 cm had statistically (P>0.05)
similar DM value, which was higher than the DM content of the forage harvested at 22.5 cm
cutting height. This could be most likely due to a relatively higher diameter of the tiller at
22.5 cm
 Grasses fertilized at the rate of 69 kg N/ha and cut at a stubble height of 15 cm showed higher
(P<0.05) content of CP than other treatment combinations (Table 4.5). This could be attributed to the
higher leaf in a 15 cm*69 kg N/ha. However, the grass fertilized with 69 and 115 kg N/ha did not
show a significant variation.
 The combined effect of 15 cm *69 kg N/ha consisted of 1.17 times higher OM than 22.5
cm *69 kg N/ha, which could be due to the fact that 15 cm*69 kg N/ha produced higher
proportion of leaf.
 The highest NDF content was 68.75% for 22.5 cm*69 kg N/ha, which could be caused by
the early maturity of the grass (Kabirizi et al., 2015b) and similarly higher result was
reported at the cutting height of 10 cm (Rahman et al., 2016)
 The grass due to the effect of 7.5 cm*161 kg N/ha produced the lowest content of ADF
(31.23%) while the highest was 50.87% for 22.5 cm*69 kg N/ha, which could be attributed
to thicker tillers for 22.5 cm*69 kg N/ha.
 The non-significant (P>0.05) effect of cutting height on the contents of ADL was in
agreement with those of Ferreira et al. (2015) and Lounglawan et al. (2014) who reported
for Napier grass.

22. Table 7. Partial Budget Analysis of Elephant Grass Fertilized with Different
Nitrogen Rates. HUSSEN FINAL THESISpartial budget analysis.docx
Descriptions
Treatments
Control
Group 69 kg N/ha
115 kg
N/ha
161 kg
N/ha
Dry matter yield (ton DM/ha) 2.73 4.29 5.09 5.34
Selling price (ETB/ha) 18741.5 29450.9 34942.9 36659.1
Purchasing price of urea fertilizer 0.0 3300.0 5500.0 7700.0
Cost of labor for land preparation 1000.0 1000.0 1000.0 1000.0
Cost of labor for pit preparation 5000.0 5000.0 5000.0 5000.0
Cost of labor for planting the culm 2500.0 2500.0 2500.0 2500.0
Cost of labor for fertilizer application 0.0 3200.0 3200.0 3200.0
Cost of labor for harvest 1500.0 1500.0 1500.0 1500.0
Cost of labor for weed management 5000.0 5000.0 5000.0 5000.0
Cost of labor for irrigation 1250.0 1250.0 1250.0 1250.0
TVC 0.0 6500.0 8700.0 10900.0
TR 2491.5 13200.9 18692.9 20409.1
NR 2491.5 6700.9 9992.9 9509.1
ΔTVC - 6500.0 8700.0 10900.0
ΔTR - 10709.4 16201.4 17917.6
ΔNR - 4209.4 7501.4 7017.6
MRR 64.8 86.2 64.4
 The rate of N fertilizer application determines the cost and biomass production of elephant
grass (Sant’Ana et al., 2018) so that Partial budget analysis is very vital to evaluate its’
economic feasibility (Adane & Girma, 2008; Oliveira et al., 2015).
 The result of this study showed that per unit of expenditure could result in a return of
0.648, 0.862, and 0.644 ETB per unit of investment for 69, 115, and 161 kg N/ha,
respectively.

23. 4. CONCLUSIONS AND RECOMMENDATIONS
4.1. Conclusions
Plant survival rate was the highest for 69 kg N ha-1
Most of the growth characteristics significantly (P<0.05) increased
as cutting height and N fertilizer increased
15 cm*161 kg N ha-1, 22.5 cm*115 kg N ha-1, 15 cm*69 kg N ha-1,
and 22.5 cm*161 Kg N ha-1 gave higher total, and leaf dry matter
and total crude protein yield.
Leaf to stem ratio tended to decrease with increasing N fertilizer.
The DM content ranged 12.4 to 20.2%
The CP content was the highest for 15 cm*69 kg N ha-1.

24. Conclusions (Cont’d)
The organic matter content was in the order of 69<115<161=0
kg N ha-1 and increased as the cutting height decreased
The acid detergent fiber was in the range of 31 to 51%
The neutral detergent fiber content increased with increasing
cutting height and decreased with increasing N fertilizer.
The partial budget analysis revealed that the net return was
higher for 115 kg N ha-1
15 cm*161 kg N ha-1, 15 cm*69 kg N ha-1, 22.5 cm*115 kg N
ha-1 yielded comparable TDMY and TCPY.
Hence, it can be concluded that 22.5 cm*115 kg N/ha gives
optimum yield and nutrient and was economically feasible.

25. 4.2. Recommendations
 Based on results of the present study, the following
recommendations and future elephant grass research priorities
are forwarded.
 The 115 kg N ha-1 being economically feasible, 22.5 cm*115 kg N ha-1 is
therefore, recommended according to the results of the current study.
 However, it should be repeated over defoliation frequencies, seasons,
and locations to come up with fine-tuned recommendations.
 For the future study, including cutting days in this study would provide
more information.

26. 5. ACKNOWLEDGEMENTS
 Woldia University
 Fasil Negussie (PhD)
 Getachew Animut (PhD)
 Mr. Ashenafi Kebede
 Mr. Addissu Degu
 Dr. Solomon Tsegaye
 Colleagues
 Farmers
 Family