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COMPARATIVE ECONOMICS OF FARM LEVEL ORGANIC AND
CONVENTIONAL SESAME (Sesamum indicum L.) PRODUCTION IN
NASARAWA STATE, NIGERIA
BY
UMAR, HARUNA SULEIMAN
PG/M.Sc/07/42731
DEPARTMENT OF AGRICULTURAL ECONOMICS,
UNIVERSITY OF NIGERIA, NSUKKA
JULY, 2010
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COMPARATIVE ECONOMICS OF FARM LEVEL ORGANIC AND
CONVENTIONAL SESAME (Sesamum indicum L.) PRODUCTION IN
NASARAWA STATE, NIGERIA.
BY
UMAR, HARUNA SULEIMAN
PG/M.Sc/07/42731
A DISSERTATION SUBMITTED TO THE DEPARMENT OF AGRICULTURAL
ECONOMICS, UNIVERSITY OF NIGERIA, NSUKKA IN PARTIAL
FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OFTHE
DEGREE OF MASTERS OF SCIENCE (M.Sc) IN AGRICULTURAL
ECONOMICS
JULY, 2010
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CERTIFICATION
UMAR, Haruna Suleiman, a postgraduate student in the Department of Agricultural
Economics with registration number PG/M.Sc/07/42731 has satisfactorily completed the
requirements for the award of Degree of Masters of Science (M.Sc) in Agricultural
Economics.
The work in this thesis is original and has not been submitted in part or in full for any
other degree or diploma of this or any other University.
------------------------------------ -------------------------------- Prof. C. U. Okoye Prof. E. C. Nwagbo (Supervisor) (Head of Department)
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DEDICATION This work is dedicated to my mum, Hassana Suleiman and daughter, Ramatu Haruna.
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ACKNOWLEDGEMENTS I wish to thank Almighty Allah for making this programme a reality. I am particularly
grateful to my supervisor, Prof. C. O. Okoye, for his contributions and guidance which
led to the completion of this work. My appreciation also goes to Head of Department,
Prof. E.C. Nwagbo, PG Seminar Coordinator, Dr. A. A. Enette and all other lecturers of
the department for their contributions to this work.
I wish to acknowledge with profound gratitude the assistance and support of my
family and friends. May Allah reward you abundantly.
To my class mates, I sincerely appreciate your efforts in creating a conducive
atmosphere for studied together in peace and harmony.
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TABLE OF CONTENTS
Title page - - - - - - - - - i
Certification - - - - - - - - - ii
Dedication - - - - - - - - - iii
Acknowledgement - - - - - - - - iv
Table of contents - - - - - - - - v
List of Tables - - - - - - - - viii
Abstract - - - - - - - - - x
CHAPTER ONE: INTRODUCTION
1.1 Background of the Study - - - - - - 1
1.2 Problem Statement - - - - - - - 5
1.3 Objectives of the Study - - - - - - 8
1.4 Hypotheses of the Study - - - - - - 9
1.5 Justification of the Study - - - - - - 9
CHAPTER TWO: LITERATURE REVIEW
2.1 Concept of Organic and Conventional Crop Production Systems - 10
2.2 Organic Crop Production Practices and Principles - - - 10
2.2.1 Organic crop production principles - - - - - 10
2.2.2 Organic crop production practices - - - - - 12
2.3 Problems and Prospects of Organic Crop Production - - 12
2.4 Conventional Crop Production Practices - - - - 16
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2.5 Sesame Crop Production - - - - - - 17
2.6 Problems of Sesame Crop Production - - - - 20
2.7 Profitability of Sesame Production Enterprise - - - 21
2.8 Total Factor Productivity - - - - - - 22
2.9 Determinants of Agricultural Productivity - - - - 22
2.10 Theoretical Framework/Analytical Framework- ---------------------------------23
2.10.1 Approaches to farm productivity measurement - - - 26
2.10.2 Multiple Regression Analysis - - - - - - 28
2.10.3 The t-test - - - - - - - - 29
2.10.4 The chow test - - - - - - - - 29
CHAPTER THREE: METHODOLOGY
3.1 Description of Study Area - - - - - - 31
3.2 Sampling Technique - - - - - - - 32
3.3 Method of Data Collection - - - - - - 33
3.4 Method of Data Analysis - - - - - - 34
3.4.1 Total Factor Productivity (TFP) Estimates - - - - 34
3.4.2 Factors Influencing TFP - - - 35
3.4.3 Gross Margin Analysis - - - - - - 35
3.4.4 Student t-test (For Testing Hypothesis i) - - - - 36
3.4.5 Chow test (For Testing Hypothesis ii) - - - - 36
3.4.6 Student t-test (For Testing Hypothesis iii) - - - - 37
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CHAPTER FOUR: RESULTS AND DISCUSSION
4.0 Results and Discussion - - - - - - 38
4.1 Socio-Economic Characteristics of Sesame Farmers - - 38
4.2.1 Organic farming practices - - - - - - 42
4.2.2 Conventional farming practices - - - - - 43
4.3 Input and Output Levels of Sesame Farms Per Hectare - - - 44
4.4 Gross Margin Analysis of Sesame Farmers - - - - 46
4.5 Total Factor Productivity Estimates - - - - - 48
4.6 Factors of TFP - - - 49
4.6.1 Regression estimates for factors of total factor productivity
of organic sesame farms - - - - - - 49
4.6.2 Regression estimates for total factor productivity
of conventional sesame farms - - - - - - 51
4.7 Hypotheses Testing - - - - - - - 53
4.8 Constraints to Sesame Production - - - - - 56
CHAPTER FIVE: SUMMARY, CONCLUSION AND RECOMMENDATION
5.0 Summary, Conclusion and Recommendation - - - 59
5.1 Summary - - - - - - - - 59
5.2 Conclusion - - - - - - - - 62
5.3 Recommendation - - - - - - 62
References - - - - - - - - 64
Appendix -------------------------------------------------------------------- 69
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LIST OF TABLE Table Page Table 1: Production costs of Organic and Conventional Crops (₦/ha) 14
Table2: Designed Sampling Structure 33
Table 3: Socio-Economic Characteristics of Sesame Farmers 39
Table 4: Distribution of Organic Sesame Farmers According to Farming Practices 43
Table 5: Distribution of Conventional Sesame Farmers According to
Farming Practices 44
Table 6: Input and output Levels of Sesame Farms 45
Table 7: Gross Margin Analysis of Sesame Farmers 47
Table 8: Percentage Distribution of Total Factor Productivity Indices for
Sesame Farms 48
Table 9: Total Factor Productivity Indices for Sesame Farms 49
Table 10: Regression Estimates for Factors of Total Factor Productivity
Of Organic Sesame Farms – Double Log function 50
Table 11: Regression Estimates for Factors of Total Factor productivity
of Conventional Sesame Farms – Linear Function 52
Table 12: Result of t-test Comparing Productivity of Organic and
Conventional Sesame Farms 54
Table 13: Result of Chow test Comparing the Influence of Identified Factors on TFP of
Organic and Conventional Sesame Farms 55
Table 14: Result of t-test Comparing Incomes from Organic and Conventional Sesame
Farms 56
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Table 15: Constraints to Organic Sesame Production 57
Table 16: Constraints to Conventional Sesame Production. 58
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ABSTRACT
The study compared economics of organic and conventional sesame production systems
in Nasarawa state. Multi-stage random sampling was used in selecting 120 farmers;
made up of 60 organic and 60 conventional farmers. Data collected through structured
questionnaire and interview schedule, were analyzed using descriptive statistics, Total
Factor Productivity analysis, OLS regression model and Gross margin analysis. The
gross margins earned per hectare were N62409 by organic farmers and N64567 by
conventional farmers. The difference in Gross margin is not significant. The average rate
of return was higher in organic farms (N3) than conventional farms (N2.8). The TFP
(productivity level) estimate was higher in organic farms (1.9) than conventional farms
(1.7) though the difference in productivity level is also not significant. Farm size, seed,
labour, and farming experience were significant at 1% while house size was significant at
5% therefore influence productivity level of organic farms. On the other hand, Farm size
was significant at 1%; seed, fertilizer and pesticide were significant at 10% while labour
was significant at 5% thereby influencing the productivity level of conventional farms.
Poor access to credit, high cost of agrochemicals and low market price are major
constraints to sesame production. Hence, to ensure sustainable farm productivity and
income, organic sesame farming should be encouraged and incorporated into
agricultural policy of the state. In order to ensure wider cultivation of sesame crop,
credit facility should be channeled to the real farmers through their cooperative
societies. Buying of excess produce from farmers at higher prices should be extended to
rural communities this will help in reducing price fluctuation and making farmers to earn
more income.
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CHAPTER ONE
INTRODUCTION
1.1 Background of the Study
Nigerian’s quest for food security and economic diversification through greater
investment in agriculture can only be met by the institution of a sustainable agricultural
production system. Jurgen (1990), defined sustainable agriculture as a system of
agriculture that is able to balance productivity with low vulnerability to problems such as
pest infestation and environmental degradation while maintaining the quality of land for
future generations. In practice, this involves a system which avoids or largely excludes
the use of synthetic compound fertilizers and pesticides. It includes the use of
technologies such as crop rotations, mechanical cultivation and biological pest control;
and such materials as legumes, crop residues, animal manures, green manures, other
organic wastes and mineral bearing rocks (Jurgen, 1990).
Today there exist widespread concerns that conventional agriculture is not
sustainable in the long term (Togun, 2004; Kuepper and Gegner, 2004; Erdemir and Zeki,
2005; Jurgen, 1990; and Rahman, et al; 2001). This is attributed mainly to the effect of
artificial fertilizers and synthetic pesticides resulting in phenomena such as pesticide
resistance and soil degradation; for examples erosion, acidity, salinity and compaction.
Organic farming is a growing trend in agricultural practice, philosophy and business in
many parts of the world that has been gaining strength since the 1980s. It is a production
system whose objective is to sustain agricultural productivity by avoiding or largely
excluding synthetic fertilizers and pesticides (Altieri and Nicholls, 2005). Kuepper and
Gegner (2004), stated that organic agriculture is an ecological production management
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system that promotes and enhances biodiversity, biological cycles and soil biological
activities. It is based on minimal use of off-farm inputs and on management practices that
restore, maintain and enhance ecological harmony.
The original philosophy that guided organic farming emphasized the use of
resources found on or near the farm. These internal or local resources include solar and
wind energy, biological pest controls, and biologically fixed nitrogen and other nutrients
released from organic matter or from soil reserves. The idea was to rely heavily on the
use of crop rotations, crop residues, animal manures, legumes, green manures, off farm
organic wastes and aspects of biological pest control for maintenance of soil productivity,
supply of plant nutrients, and regulation of insect pests, weeds, and diseases.
There are about 23 million hectares of land under organic management
worldwide, of which 10.6 million hectares and 3.2 million hectares are in Australia and
Argentina respectively. More than 4 million hectares are under certified organic farming
in Europe. In Italy alone there are about 56,000 organic farms occupying 1.2 million
hectares. In Germany, there are about 8,000 organic farms occupying about 2% of the
total arable land. In North America, about 1.5 million hectares are certified organic
(45,000 organic farms) occupying 0.25% of the total agricultural land (Altieri and
Nicholls, 2005). In Africa and Nigeria in particular, organic farming is an old farming
practice. According to Haverkort and Waters – Bayer (1992), agriculture in the tropics
depended on local natural resources, local knowledge and skills, and institutions; and it
was this local practice that gave rise to site-specific and organic farming system. View
that was shared by Obinne et al; (2008), and Olabiyi et al; (2008).
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Conventional agriculture is generally used to portray agricultural practices relying on
chemical and energy inputs typical of large-scale, mechanized farms. Mould-board
ploughing to cover stubble, routine pesticide spraying, and use of synthetic fertilizers are
examples of conventional practices (Philip, 2009). The practices of conventional
agriculture all tend to compromise future productivity in favour of high productivity in
the present.
Within the context of this study, organic crop production system can be considered
as a farming practice that excludes the application of chemical fertilizers and pesticides to
the sesame farms. That is organic sesame farmers are those farmers who do not use
chemical fertilizers, pesticides and/or herbicides consciously or unconsciously on their
farms at least for two consecutive planting seasons but instead depend on ecological
friendly management practices like application of organic manure, natural pesticides, and
practices of green manure, cover cropping, crop rotation etc. While conventional sesame
farmers are farmers that apply agro chemicals in form of chemical fertilizers, pesticides
and/or herbicides on their farms at least for two consecutive planting seasons.
Sesame (Sesamum indicum L.) is an East Indian flowering plant that comes from
the family of pedalliaceae and the genus Sesamum. The plant is an erect tropical annual
herb having white and purple flowers that bear tiny, flat, nutty flavoured seeds that are
oval in shape. Sesame is renowned for its seeds, which are a source of very useful sesame
oil and are also used as a flavouring agent (National Multi Commodity Exchange of
India, 2007). It is one of the oldest cultivated plants in the world. It was a highly prized
oil crop of Babylon and Assyria at least 4,000 years ago. Today, India and China are the
World’s largest producers of sesame, followed by Burma, Sudan, Mexico, Nigeria,
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Venezuela, Turkey, Uganda and Ethiopia (Oplinger et al, 2007). Their production outputs
in the year 2005 are given as follows: China (725,470 MT), India (680,000MT),
Myanmar (550,000MT), Sudan (300,000MT), Uganda (110,000MT), Nigeria
(75,000MT), Pakistan (68,000MT), Ethiopia (65,000MT), Bangladesh (50,000MT),
Central African Republic (42800MT) and Thailand (42,000MT) (NMCEI, 2007).
Nigeria is a major exporter of sesame, which rated second to cocoa in export
volume. Sesame from Nigeria is exported to markets in North America, Europe and East
Asia. Benue and Nasarawa States are the highest sesame producers in Nigeria with an
annual outputs of not less than an average of 40,000MT each per annum (Raw Materials
Research and Development Council, 2004).
Sesame seeds (approximately 50% oil and 25% protein) are used in baking, candy
making, and other food industries. Oil from the seed is used in cooking and salad oils and
margarine. The oil can also be used in the manufacture of soaps, paints, perfumes,
pharmaceuticals and insecticides. Sesame meal, left after the oil is pressed from the seed,
is an excellent high protein (34-50%) feed for poultry and livestock (Oplinger et al;
2007).
As a raw export commodity, sesame seed from Nigeria is enjoying a rising profile
on the world market where overall global demand has risen to 3.3 million tons. Sesame
like other raw agricultural commodities has over 15% margin in terms of value –added
products compared to other crops. For instance, in the year 2000, while a tone of sesame
raw seed was selling for about $720 (₦72,000), the processed oil of the same quantity
was selling for $3,500 (₦350,000) (RMRDC, 2004).
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It is believed that with the growing awareness about the ill effects of the
chemicals applied to the crop in the form of pesticides, fungicides and fertilizers etc, the
development and adoption of organic technology is most essential for sustainability of
production and agro-ecosystems. Duhoon et al; (2004) stated that the result of studies on
the optimization of sesame production through the use of bio/natural inputs confirmed the
feasibility of substituting chemical fertilizer and pesticides by organic resources without
sacrificing the yield levels in sesame crop.
1.2 Problem Statement
Sesame is one of the major cash crops grown in Nasarawa State. It is a very
popular crop among the rural farmers because of the good local and international market
for its seed and oil. The Nasarawa State Government has identified sesame as a major
revenue earner and hosted a seminar to highlight its potentials in 2004. It has also
established sesame seeds cleaning plant in the state to serve as a catalyst for industrial
development. There are already buyers from China and other parts of the Asian countries
that patronize the product (Nasarawa State Government, 2008). According to Idowu
(2002), sesame production in Nasarawa state has increased substantially in the last 5
years. An average yield of 500kg of sesame is obtainable per hectare in this state while
the potential yield is 800kg – 1000kg per hectare. The Nasarawa State sesame crop
production figures for 2002-2006 indicated that the average yield per hectare were 620kg
in 2002, 650kg in 2003, 650kg in 2004, 700kg in 2005 and 710kg in 2006. RMRDC
(2004), identified shortages of fertilizers, agro-chemicals, improved seeds, lack of access
to agricultural loan and tractors for cultivation as major problems hindering sesame
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production in the country. Food production, farm incomes and food prices are vulnerable
to inadequacy in supply and high cost of chemical fertilizers in Nigeria (Rahman et al;
2001). Where chemical fertilizers are available, excessive usage increases pollution,
decreases soil productivity and leads to nutrient imbalance (Duhoon et al; 2004).
Application of large quantities of soluble fertilizer to a crop one, two or three times per
season floods that plant with those nutrients, stimulating certain problem weed species
and causing nutritional imbalances that lead to crop disease, insect infestations and
reduced food quality (Kuepper and Gegner, 2004). Soluble nutrients, especially nitrate,
are prone to leaching, which can cause a number of environmental and health problems
(Kuepper and Gegner, 2004). Furthermore, presence of pesticide residue in sesame had
been the major impediment in the promotion of sesame export. For instance, export
consignments of Indian sesame are sometimes rejected in the international market due to
the presence of pesticide residue. Organically produced sesame is preferred and given
premium in the global market (Duhoo et al, 2004). Many traditional sesame farmers do
not use herbicides and insecticides on their crops, which is why major buyers from Japan
prefer to buy sesame from Nigeria (Coote, 1998).
The use of organic sources will reduce the dependence on chemical fertilizers and
pesticides besides their eco-friendly nature. Keller et al;(2002), observed that organic
farming gave higher or equal yield as compared to chemical farming after an initial
period of three years; and it also improved the quality of the produce in terms of bold
sized grains, high protein content compared with chemical farming. Lauren (2007), stated
that organic farming can yield up to three times as much food on individual farms in
developing countries, as low-intensive methods on the same land. The result of
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comparative effectiveness of organic based fertilizer (OBF) with mineral fertilizer on
crop yield indicated high effectiveness of OBF on crop performance and is well
comparable with the chemical fertilizers (Adediran et al; 1999). Ash derived from burnt
vegetation is known to reduce soil acidity, increase availability of cationic nutrient and
improve yield of millet in Zambia (Araki, 1993).
Some studies have been carried out on comparism between organic and inorganic
fertilizers effect on crop production (Rahman et al; 2001; Adediran et al, 1999; and
Zeidan, 2007). All these studies were restricted mainly to comparing effects of organic
and inorganic fertilizers on crop productivity. Obinne et al; (2008) studied classification
and utilization of organic farming practices in Otukpo and Ohimimi LGAs of Benue
state. In their study no attempt was made to compare organic and conventional farming in
terms of yield and profitability. However, the work of Erdemir and Zeki (2005) and
Duhoon et al; (2004), actually focused on comparism of organic and conventional crop
production. But the setbacks on both works are: while Duhoon et al; (2004) studied and
compared yields of sesame from both enterprises without looking at profitability and
factor productivity, Erdemir and Zeki (2005), on other hand, compared the organic and
conventional grape crop production in terms of yield and profitability. The only
difference from this study is that the work is on grape crop and did not consider factors
productivity. Thus, there is very little or no empirical work on the subject matter in the
state. This therefore informs the need for this study.
The study is aimed at finding answers to the following research questions:-
i what kind of organic sesame farming practices are common in the area?
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ii what are the types and levels of inputs used in organic and conventional sesame
farms?
iii what are the returns from organic and conventional sesame enterprises in Nasarawa
State?
iv is there any significant differences between productivity of organic and conventional
sesame farms?
v what factors determine productivity in the two farm types?
vi what are the constraints limiting sesame production from both organic and
conventional farms?
1.3 Objectives of the Study
The broad objective of the study is to compare economics of farm level organic
and conventional sesame production in Nasarawa State. Specifically, the study is
intended to:
i. identify existing organic and conventional sesame farming practices;
ii. ascertain and compare the input and output levels of both organic and
conventional sesame farms;
iii. estimate and compare total factor productivity in organic and conventional
sesame farms;
iv. identify some factors influencing total factor productivity in organic and
conventional sesame enterprises;
v. determine and compare enterprise profitability of organic and conventional
sesame farms;
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vi. identify constraints faced by organic and conventional sesame farmers; and,
vii. proffer recommendations based on the findings.
1.4 Hypotheses of the Study
Based on stated objectives of the study, the following null hypotheses
were tested:
i. There is no significant difference between productivity of organic and
conventional sesame enterprises.
ii. There is no significant difference between influence of the identified factors
on Total Factor Productivity of organic and conventional farms.
iii. There is no significant difference between amount of income earned from
organic and conventional sesame enterprises.
1.5 Justification of the Study
The results of this study would be useful to the policy makers in designing appropriate
policy towards boosting organic farming as an alternative to conventional farming by
way of encouraging more researches in this area. The findings of study would also help
poor farmers to make informed decision towards choosing between conventional and
organic farming practices to enhance income.
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CHAPTER TWO
LITERATURE REVIEW
2.1 Concept of Organic and Conventional Crop Production
Organic crop production is a system of farming based on management practices
that promote and enhance farm biodiversity, biological cycles, and soil biological activity
(Heiniger and Hamilton, 2005). Organic agriculture strives to minimize use of off-farm
inputs and relies on management practices that restore, maintain and enhance the soil
ecology and the farm landscape (Heiniger and Hamilton, 2005 and NOSB, 1999). It is a
production system whose objective is to sustain agricultural productivity by avoiding or
largely excluding synthetic fertilizers and pesticides (Altieri and Nicholls, 2005; Jurgen,
1990). Conversely, conventional crop production is a system of farming based on
modernization of agriculture which relies mainly on industrially manufactured agro
chemicals like chemical fertilizers, pesticides and herbicides. This production system is
not sustainable as it is vulnerable to environmental degradation and human health risks
(Kuepper and Gegner, 2004).
2.2 Organic Crop Production Practices and Principles
2.2.1 Organic crop production principles.
According to Kuepper and Gegner (2004), there are several compelling principles
that characterize certified organic farming. They include biodiversity, integration,
sustainability, natural plant nutrition, natural pest management and integrity. Most
organic operations will reflect all of these to a greater or lesser degree. Since each farm is
a distinct entity, there is a large degree of variation.
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Diversification and integration of enterprises. The drive to build biodiversity in
organic systems encourages diversity among enterprises, but not as isolated or
independent entities. It requires integration of crops and livestock. Forage legumes in
rotation fix a sustainable supply of nitrogen in the soil that feeds subsequent non-legume
crops in rotation; manure from the livestock enterprise is conserved as a nutrient resource
and recycled back to the crop fields. Farms such as these have the additional advantage of
greater economic sustainability as their risks are spread over several livestock and crop
enterprises (Kuepper and Gegner, 2004).
Sustainability. In addition to the great economic sustainability afforded by enterprise
diversification, organic farmers are often performing well on many of the measurable
indicators associated with sustainability, such as energy consumption and environmental
protection (Gold, 2007).
Natural pest management. Whether conventional or organic, all farmers are concerned
with pests. They spend a lot of time and resources controlling them. However, in the
organic agriculture, pests whether weeds, insects or diseases are not simply scourge.
They are indicators of how far a production system has strayed from the natural
ecosystems it should imitated (Kuepper and Gegner, 2004). Certain weeds, for example,
tend to predominate when soils are too acidic or too basic; some become a problem when
soil structure is poor and conditions become anaerobic; others may be stimulated by
excessive fertilizer. In nature, massive pest outbreaks are relatively rare and short-lived,
due to the presence of natural predators, parasites and disease agents that quickly knock
the pest numbers down to a moderate level.
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Natural plant nutrition. Strategies the organic farmers will employ to build the soil are
crop rotations, animal and green manures and cover cropping.
Integrity. Integrity here refers to the systems in place and actions undertaken to assure
that consumers of organic products get what they pay for. That is organic products are
protected from contamination and from commingling with non-organic products.
2.2.2 Organic crop production practices
According to USDA (2006), organic farming entails the following practices.
- Use of cover crops, green manures, animal manures and crop rotations to fertilize
the soil, maximize biological activity and maintain long-term soil health;
- Use of biological control, crop rotations and other techniques to manage weeds,
insects and diseases;
- An emphasis on biodiversity of the agricultural system and the surrounding
environment;
- Using rotational grazing and mixed forage pastures for livestock operations and
alternative health care for animal wellbeing;
- Reduction of external and off-farm inputs and elimination of synthetic pesticides
and fertilizers.
- A focus on renewable resources, soil and water conservation, and management
practices that restore, maintain and enhance ecological balance.
In short, the organic crop production practices include the following:
2.3 Problems and Prospect of Organic Crop Production
Even though organic farming is being advocated world-wide as agricultural
practice that has become idealized alternative for providing clean, healthy food and
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environmental protection, for sustainable food production, many challenges still confront
its practitioners.
Yield of organic products. The World Bank (2005), stated that decline in yields between
10-30% has been reported as a result of the conversion from conventional agriculture to
organic production system. The extents of declining yields depend on physical farm
characteristics, farm management, and previous chemicals input usage. Erdemir and Zeki
(2005), have reported 8% declined of yield from the organic farms compare to the
conventional farms in research period.
Labour cost. Organic production systems often use more labour because they need
additional soil conservation measures – such as new management practices, manual
control of weeds, pests and diseases, and applying large volumes of organic fertilizers.
The combined effect on production costs from increased labour requirements and lower
chemical inputs will vary and must be assessed in relation to other factors, particularly
yield and price changes. In places where chemical input is low, total costs are likely to
rise because labour cost increases are likely to exceed chemical savings (World Bank,
2005).
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Table 1: Production costs of Organic and Conventional Crops (₦/ha)
Crop Organic Conventional
Sugarcane (Argentina)
Production cost (PC) 73500 84300
Labour cost (LC) 35700 23100
LC/PC(%) 49 27
Coffee (Mexico)
Production cost (PC) 102000 67800
Labour cost (LC) 78300 54000
LC/PC (%) 77 80
Banana (Dominican Republic)
Production Cost (PC) 384000 355500
Labour Cost (LC) 273900 182700
LC/PC (%) 71 51
Source: Damiani, (2002).
Technology issues. Organic production requires a high level of managerial knowledge
and ability to protect crops from pests and diseases and to comply with the production
process requirements. Access to adequate quantities of organic inputs, such as natural
pest enemies, livestock manures, mineral rock phosphate, and organic matter can be a
problem (World Bank, 2005).
Pests and diseases incidence. Cultural practices such as organic manure application can
affect soil fertility and cause insect pest and disease incidence on the plant. For instance,
increasing rate of poultry manure significantly (p<0.05) increased aphid, mirid and
grasshopper infestations as well as incidence of pepper veinal mottle virus symptoms on
pepper plants (Capsicum species) compared to where no manure was applied (Echeszona
and Nganwuchu, 2006).
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However, organic agriculture can improve farmer’s incomes and the management
of natural resources. It must be based on sustainable comparative advantage and is likely
to be most successful in areas with effective research and extension systems, a supportive
policy and regulatory framework, necessary infrastructure and adequate certification
systems (World Bank, 2005). There has been reported cases of success and improvement
of organic farming world wide: Lauren (2007), reported that organic farming can yield up
to three times as much food on individual farms in developing countries, as low-intensive
methods on the same land. The United Nations Food and Agricultural Organization
(FAO) have come out in favour of organic agriculture. Its report “Organic Agriculture
and Food Security” states that organic agriculture can address local and global food
security challenges (Lauren, 2007). According to Kathleen et al; (2008), over nine years
of comparison, there was no significant difference in corn or soybean yields in the
organic and conventional systems. Organic corn yields in the long rotation over a 9-yr
period were 9914 kg/ha compared to 10113kg/ha in the conventional system and organic
soybeans in the same rotation yielded 3043kg/ha while conventional yields average 2906
kg/ha. They also observed that soil quality remains high in the organic system, with soil
organic carbon and mineralizable nitrogen greater in the organic rotations relative to
conventional, demonstrating greater C-sequestration potential and N-use efficiency in the
organic system.
The World Bank (2005), stated that small farmers may have competitive
advantage in organic farming and can benefit in several ways:
- Production cost may be reduced by substituting labour and organic inputs for
chemical inputs that are often more expensive and difficult to obtain.
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- Organic production may reduce health risks from handling chemical inputs.
- Soil conservation measures and control of pests and diseases with manual and
biological methods may reduce contamination of natural resources.
According to Berntsen et al; (2006), organic farming is considered an effective
means of reducing nitrogen losses compared with more intensive conventional farming
system. Wood ash applied to soil increased soil organic matter, N,P,K, Ca, Mg and yields
of maize and yam. The 4t/ha ash is recommended. It increased yields of maize and yam
by 52 and 48% respectively (Owolabi, et al; 2003). Application of poultry manure and
other farm wastes have been found to increase the carbon content, water holding
capacity, aggregation of the soil and a decrease in the bulk density (Echezona and
Nganwuchu, 2006). This can helps in checking or reducing the effect of water and wind
induced erosion. Organic farming enables small holders to achieve household food
security and earn modest incomes while regenerating the land, regaining biodiversity and
supply quality food to local communities (Vossenaar et al; 2004).
2.4 Conventional Crop Production Practices
Conventional agriculture is built around two related goals: The maximization of product
and maximization of profits. In pursuit of these goals, a host of practices have been
developed without regard for their unintended, long-term consequences and without
consideration of the ecological dynamics of agro ecosystems (Stephen, 1997). Six basic
practices of conventional agriculture are intensive tillage, monoculture, and irrigation,
application of inorganic fertilizers, chemical pest control, and genetic manipulation of
crop plants. Each is used for its individual contribution to productivity, but as a whole the
28
practices form a system in which each depends on the others and reinforce the necessity
of using the others (Stephen, 1997).
2.5 Sesame Crop Production
Sesame (Sesamum indicum L.) in Nigeria is mainly cultivated between latitudes
60 and 100N covering the derived Southern and Northern Guinea Savanna, Sudan
Savanna and Sahel Vegetation zones. The major producing states are Adamawa, Benue,
Borno, Gombe, Kogi, Jigawa, Kano, Nasarawa, Katsina, Kaduna, Plateau, Yobe,
Zamfara, Taraba, Kebbi, Sokoto, Cross River and the Federal Capital Territory, Abuja
(RMRDC, 2004). Beniseed as it is popularly called, will thrive in most agro ecologies
suitable for cereal crops production in the country. But production is better suited for the
well drained up land areas. Depressions and valley bottoms such as fadamas with poorly
drained soils are generally avoided.
Growth habits. Sesame is an erect annual (or occasionally a perennial) that grows to a
height of 20 to 60 inches, depending on the variety and the growing conditions. Some
varieties are highly branched, while others are unbranched. Leaves are variable in shape
and size and may be opposite or alternate. The bell shaped white to pale-rose flowers
begin to develop in the leaf axil 6 to 8 weeks after planting and this continues for several
weeks. Multiple flowering is favoured by opposite leaves. Sesame is normally self-
pollinated, although cross pollination by insects is common. The fruit is a deeply groove
capsule (1 to 3 inches in length) that contains 50 to 100 or more seeds. The seeds mature
4 to 6 weeks after fertilization. The growth of sesame is indeterminate, that is the plant
continues to produce leaves, flowers and capsules as long as the weather permits. Sesame
seeds are small and vary in colour (Oplinger et al; 2007).
29
Environment Requirements
Climate. Sesame is considered to be basically a crop of the warm region of the tropics
and subtropics. It is very drought-tolerant, due in part to an extensive root system.
Sesame normally requires fairly hot condition during growth to produce maximum yield.
A temperature of 250C – 270C (77-810F) encourages rapid germination, initiate growth,
and flower formation. It requires adequate moisture for germination and early growth and
a minimum rainfall of 20 to 26 inches or 50 to 65cm per season is necessary for
reasonable yields. Moisture levels before planting and flowering have the greatest impact
on yield. Sesame is intolerant of water-logging. Rainfall late in the season prolongs
growth and increases shattering losses. Initiation of flowering is sensitive to photo period
and varies among varieties. The oil content of the seed tends to increase with increased
photoperiod. Because protein content and oil content are inversely proportional, seed
with increased oil content has decreased protein content (Oplinger et al; 2007).
Soil. Sesame is adaptable to many soil types, but it thrives best on well-drained, fertile
soils of medium texture and neutral pH. The site selected should be fairly flat and well
drained loamy or sandy loam soil. Sesame, which has an extensively branched feeder root
system, appears to improve soil structure. Sesame has a very low salt tolerance and
cannot tolerate wet conditions (Oplinger et al, 2007).
Cultural Practices
Seedbed preparation. Sesame requires a warm, moist, weed-free seedbed. Good
drainage is important, because the plant is extremely susceptible to water logging at any
stage of growth. Since sesame is planted late, several generations of weeds can be killed
by repeated tillage before planting.
30
Planting date. This depends on the ecological zone. In Guinea Savanna, early planting is
by March/April. Late planting is by mid-July/early August. In Sudan Savanna, planting is
by late June to first week of July. In Sahel, planting is by the first rain (RMRDC, 2004).
Method and rate of seeding. Planting on flat is done at a spacing of 60cm (inter-row)
and 10cm (intra-row). Planting on ridges at 75cm (inter-row) and 15cm (intra-row).
Planting on ridges is ideal when inter-cropped. Planting by broadcasting is useful where
area of cultivation is small. It ensures quick crop coverage. 5kg/ha of seeds is required
for planting by using broadcasting method, 4kg/ha by seed drilling on flat land and
3.5kg/ha when planting on ridges (RMRDC, 2004).
Fertilizer application. Sesame does not require much fertilizer except where the soil is
very poor. The fertilizer most frequently applied to smallholder crops is organic either
animal manure of some kind, waste products from the homestead or previous crop
residues. These are usually effective in increasing yields of the local variety, and are of
general benefit to all crops grown in rotation (Weiss, 1971). NPK fertilizer is required
where the soil fertility is low. Two bags of NPK fertilizer (15:15:15) is averagely
required for one hectare. The recommended rates are: Nitrogen (N) 20-50kg/ha,
phosphorus (P) 30-60 kg/ha, potassium (k) 30-35kg/ha. This is equivalent to 2 bags of
NPK and 3 bags of SSP (RMRDC, 2004).
Weed control. Hoe weeding twice at 3 and 9 weeks after planting is recommended.
Chemical weed control can be done with pre-emergence herbicides (like scapter: 0.20kg
a i/ha, machete: 4lt/ha, Galex: 2.5lt/ha). Post –emergence herbicides like fusillade:
2lt/ha,
31
Disease and pest control. Benlate and difolatan or any available fungicide can be used to
control cercospora leaf spot. For insect control, spray sesame plants with Decis 2.5EC
(25ml/15 Lt) Novacron and Azodrin (50ml/15Lt).
Varieties of sesame. Early maturing (matures in 90-100 days): E8. Medium maturing
(matures 100-125 days): NCR1-BEN-01m, NCR1 – BEN- 02m and Yandev – 55. Late
Maturing (125-140days): NCRI-BEN-032.
Harvesting. Harvest sesame from the field when about 50% of the capsules turn yellow.
Delay harvesting should be avoided to prevent seed loss through shattering.
2.6 Problems of Sesame Crop Production
According to RMRDC (2004), the general problems of sesame production and
processing in Nigeria are: shortage of fertilizers, agro-chemicals, improved seeds, and
tractors for cultivation. Other problems are lack of access to agricultural loan, frustration
in the disposal of produce due to very low price offers, poor storage and processing
facilities. Generally, the states of rural roads were bad making transportation of produce
to market very expensive. It further observed that apart from having limited access to
credit facility from the federal government, of the very small facility available, only 5%
of the agricultural loans reached the small scale farmers, the rest being diverted to state
agencies and large-scale farmers, despite the fact that more than 80% of agricultural
produce are produced by small scale farmers. In the same vein, despite the subsidy on
farm-inputs by the government, such as fertilizers and agrochemicals, they are scarcely
available to the farmers through official channels and that most farmers are forced to buy
at high prices in the open market.
32
2.7 Profitability of Sesame Production Enterprises
Profit is commonly refers to the act of making gain in business operation. An
economic profit from the farm business arises when its revenue exceeds the total
(opportunity) cost of its inputs. Profitability is calculated to measure the operating
efficiency of the firm (Arene, 1998).
The profitability analysis of sesame production enterprise measures the economic
or the operating efficiency of the sesame farms. A survey conducted by National Cereal
Research Institute in 2000 in Nasarawa state of Nigeria, showed that the average
production cost of one hectare of sesame farm is N8,600, and the gross margin of
production is about N13,900. This value gives a cost/benefit ratio of N2.62. This implies
that for every N1.00 invested on sesame production, N2.62 is realizable.
Profitability analysis of crop production under organic farming has shown
appreciable returns to the farmers. According to Kathleen et al; (2008), over nine years,
revenues generated from Organic corn crops increased average revenues by a factor of
1.67 over conventional corn, while organic soybean revenues were 2.32 times greater
than conventional soybean revenues. Erdemir and Zeki (2005), observed that variable
costs and production costs per hectare was higher on organic grape farms and net income
per hectare was 16% lower than conventional raisin (grape) farms. Another study done on
organic farm profitability analysis in Europe by Vossemaar, Jha and Wynen (2004),
observed that profits were comparable between organic and conventional farms, though
they varied considerably by both locality (country) and kind of enterprises. These
empirical data would form the basis for comparism to the results of this study.
33
2.8 Total Factor Productivity
Productivity is defined as the ratio of the output that a farm produces to the inputs
it uses. Total factor productivity is a form of productivity measure involving all factors of
production. Other traditional measures of productivity, such as labour productivity in a
factory, fuel productivity in power station and land productivity (yield) in farm are often
called partial measure of productivity. These partial measures can provide a misleading
indication of overall productivity when considered in isolation (Coelli, Rao and Battesse,
1998). Fried, Lovell and Schmidt (1993), emphasized that productivity varies due to
differences in production technology, differences in the efficiency of the production
process, and differences in the environment in which production occurs. In the study of
productivity Analysis of Cassava-Based Production Systems in the Guinea Savannah of
Nigeria, Fakayode et al; (2008), observed that cassava/maize enterprise has the higher
Total Factor Productivity level of 4.4 compare to 3.5 TFP level in cassava/cowpea. This
is because Average Variable Cost incurred was lesser in cassava/maize enterprise than
cassava/ cowpea.
2.9 Determinants of Agricultural Productivity
Hussain and Perera (2004), classified the determinants of agricultural productivity
as follows:
i. Land and water related factors (such as farm water course, location, quality of land,
sources of water, quality and quantity of water and timing of water application, etc).
ii. Climatic factors (i.e. rainfall, temperature, sunshine, frost, etc).
iii. Agronomic factors such as quality, quantity and timing of input application (i.e.
seeds, fertilizers, herbicides, labour, etc).
34
iv. Socio-economic factors (such as farmers’ health, education, experience in farming,
farm size, tenancy terms, land fragmentation and availability of credit).
v. Farm management factor (i.e. adoption of modern production technologies, farm
planning and management practices, etc. According to Fakayode et al; (2008), other
factors responsible for agricultural productivity change include technology, labour
employment, education and training of farm operators, agro-environmental
conditions, security of land ownership rights and fund.
Some of these factors are interrelated and the effects of some of them may be
much greater than those of others and there may be locational variations in the degree of
their effects on productivity. Some of these factors may be under the direct control of all
the farmers. Others may be controlled by groups of other farmers, managers at the system
level and policy-makers at higher levels. Yet some of these are beyond human control.
Fakayode et al; (2008), identified socioeconomic factors like land, labour, educational
status, and fertilizer as the determinants of Total Factor Productivity in cassava-based
enterprises, since TFP was significantly influenced by the factors.
2.10 Theoretical Framework/ Analytical Framework
Organic farming is a production system whose objective is to sustain agricultural
productivity through sustainable natural resource management. Management of natural
resources like use of green manures, biological pest control, crop residues, crop rotations,
animal manures for sustainable agricultural productivity is a subject matter in Natural
Resource Economics. Therefore, this study is based on the theory of Natural Resource
Economics. According to Ahmed (2000), in natural resource economics the emphasis is
on the intertemporal allocation of extractive nonrenewable resources and the harvest of
35
renewable resources such as forest and other plant and animal products. Sustainability is
fundamentally a matter of natural resource management.
In recent years, increases in agricultural productivity have come in part at the
expense of deterioration of the natural resource base on which farming systems depend. It
is urgent that this trend be reversed, by encouraging farmers to adopt more sustainable
methods of farming that will have long-term benefits in environmental conservation and
development of sustainable livelihoods. Sustainable natural resource management
optimizes the use of resources to meet current livelihood needs, while maintaining and
improving the stock and quality of resources so that future generations will be able to
meet their needs (World Bank, 2005). According to food and Agricultural Organization
Statistical data base (2003), conventional agricultural production has made significant
impact on the natural resource base:
The amount of agricultural land going out of production each year due to soil
erosion is about 20 million hectares, and approximately 40% of the world’s crop
land is now degraded. It was found that 24% of Enugu State farmers’ spending
on tillage/cultural practices was directed at the institution of soil erosion control
measures, and that erosion control-related defensive expenditure by the farmers
was 3.7 times more than erosion damage costs (Okoye, 2006).
Irrigated agriculture consumes about 70% of the total volume of fresh water used
by humans, resulting in major environmental consequences: salinization, lowering
of water tables, water logging, and degradation of water quality, with subsequent
impacts on ecological systems affecting fisheries and wetlands.
36
Agriculture currently contributes about 30% of the global emission of green house
gases resulting from human activity. This has major implications for global
climate change.
The unplanned expansion of intensive production systems, which are typically
monoculture, can contribute to a significant loss in biodiversity.
Deforestation rates have reached almost one percent per year in some regions.
The World Bank (2005), observed that sustainable Natural Resource Management
is important to agricultural development as a basis for:
General agricultural productivity. Agriculture is the major user of most available
land and water resources. However, many farmers lack essential knowledge,
resources, and skills to manage intensive farming operations on a sound basis.
This leads to use of inappropriate technologies and unsustainable practices that
contribute to exhaustion of natural resources and environmental pollution.
Off-farm agricultural uses. Many agricultural systems rely on “off-farm” natural
resources, such as livestock manures. Forests provide building materials for
farms, fences and homes.
Risk and vulnerability reduction. Sustainable natural resource management
reduces vulnerability of farm to natural resource disasters, such as droughts,
floods and to the loss of biodiversity from overgrazing and deforestation.
Pollution reduction. Pollution from agricultural production and processing can
have major impacts on environmental quality. Water pollution from agricultural
chemical use as a potential health hazard, irrigation use can cause salinity
problems, and burning crop residues may affect air quality and human health.
37
Hence, sustainable agriculture should be based on approaches that reduce
environmental degradation, conserve natural resources and provide an adequate and
dependable farm income thereby reducing poverty and associated problems. This is the
main issue of focus in organic farming.
2.10.1 Approaches to farm productivity measurement. A study where productivity of
farms are estimated by looking at overall effects of factors or inputs employed for
production on output in order to ascertain the efficiency with which farmers use resources
on their farms, total factor productivity analysis becomes imperative. There are two
approaches to the measurement of productivity namely: (i) the growth accounting
approach which is based on index numbers, and (ii) the parametric approach which is
based on an econometric estimation of the production, cost, or profit functions (Alene
and Hassan, 2003).
(i) The Index Number Approach. In this approach, the total output and total input are
measured in an index form. Earlier approaches to TFP measurement used the
Laspeyres and Paasch indexing procedures. However, these indexing procedures
are in-exact except when the production function is linear and all inputs are
perfect substitutes in the relevant range.
(ii) The parametric Approach. Conceptually, the parametric approach is based on the
econometric estimation of production function, cost function or profit function.
According to Key and Mcbride (2003), TFP is measured as the inverse of unit
cost. This is so since TFP is the ratio of the output to the total variable cost
(TVC).
TFP = Y ……………………………… 1 TVC Where y = quantity of output and TVC = total variable cost.
TFP = Y i = 1,2,………….., n 2
38
∑PiXi Where Pi = unit price of the variable input and Xi = quantity of ith variable input.
This methodology ignores the role of total fixed cost (TFC) as it does not affect both the
profit maximization and the resource – use efficiency conditions. In any case it is fixed,
then it is a constant (Fakayode et al, 2008).
Derivation of the TFP formula:
From cost theory TC = TVC + TFC ……………………… 3
Divide equation (3) through by Y
TC = TVC + TFC ……………………………………... 4 Y Y Y
This equals ATC = AVC + AFC …………………………… 5
But AVC = TVC Y
Where ATC = Average Total Cost
AVC = Average Variable Cost
AFC = Average Fixed Cost
If TFP= Y then TFP = 1 ………………………….. 6 TVC, AVC
Therefore, TFP is the inverse of the AVC and TFP = Y i =1,2….n ∑PiXi
Applicability of this method in the study. This approach can be applied in this study
since TFP ignores the role of total fixed cost (TFC) as this does not affect both the profit
maximization and the resource – use efficiency particularly in the short run.
39
2.10.2 Multiple Regression Analysis
In a study where the relationship between the dependent and independent
variables are estimated, the most analytical technique used is the regression analysis.
Multiple regression analysis is an econometric tool used to estimate variables
(Koutsoyiannis, 1977). It is used to determine how changes in a given variable
(independent variables) affect other variable (dependent variable). The independent
variables are used to induce change or explain the behavior of dependent variable. The
multiple regression model can be expressed implicitly or explicitly. Mathematically, the
implicit form is expressed as
Y = f(X1, X2, X3 X4 ……………… Xn) + µ
Where;
Y = Dependent variable (TFP)
X1 – Xn = Independent variables (Identified factors)
f = functional relationship which shows how Xs are transformed to Y
µ = Error term.
While the explicit form is expressed as:
Y = bo + bixi + b2 x2 + b3x3 - ….. bnxn + µ
Where
Y = Dependent variable
bo = Constant
b1, b2, b3 …………… bn = Parameter estimate (coefficients)
µ = Error term
40
Applicability of this method in the study: this method was used to examine the extent
of influence of identified factors on total factor productivity of both organic and
conventional sesame production enterprises. That is examining the influence of each of
the identified factors on the farm level productivity.
2.10.3 The t-test
In studies where two sets of variable effects are to be compared and tested
hypothetically about the difference between their means, the student t-test is often
applied. It is used in testing hypotheses about the difference between population of
groups when the sample size is small, usually, n<30 (Koutsoyiannis, 1977). The t-
distribution is always symmetric, with mean equal to zero and variance which approach
unity when is large. Clearly as n increases, the t distribution approaches the standard
normal distribution. In this study, student t-test was used to compare enterprise
profitability and total factor productivity between organic and conventional sesame
production enterprises.
2.10.4 The Chow Test
The chow test is used in testing equality between coefficients obtained from different
samples ( Koutsoyiannis, 1977). If there are two samples on the variables Y and X1, the
one containing n1 observations and the other n2 observations, and we use them separately
for estimation of the relationship between Y and X, then we will obtained two estimates
of the same relationship for two different cross section samples.
The chow test was used to test whether the dependent variable Y in different conditions
implied by two regression equations are equal for independent sample sets n1 and n2
respectively and to test if the influences of the independent variables Xis are equal on the
41
dependent variable Y in two conditions implied by two regression equations for
independent sample sets n1 and n2 respectively.
The two equations involved are:
TFP= bo + b11X1 + b12X2 + b13X3 + b14X4……………….b18X8+ u (for organic farm n1)
TFP= bo + b21X1 + b22X2 + b23X3 + b24X4…………..b28X8+ u (for conventional farm n2)
The two sets (n1 + n2) are pooled together forming a sample of (n1 + n2) observations.
From this a pooled function can be written as follow:
TFP3i= b3 + b31X1 +b32X2 + b33X3 + b34X4……….b38X8 + u for combined
sets (n1 +n2).
42
CHAPTER THREE
METHODOLOGY
3.1 Description of Study Area
The study was conducted in Nasarawa state of Nigeria. Nasarawa state with a land
mass of 12000 square kilometers is located in the middle belt zone or North Central of
the country. It lies between latitude 70 and 90 N and longitude 70 and 100E. The state has
a climate typical of the tropical zone because if its location. It has a mean temperature
ranging from 250C to 360C. Rainfall varies from 1310.73mm in some places to 1450mm
in others. It is characterized by two distinct seasons: dry and wet. The dry season span
from November to February, while the raining season is from March to October
(Nasarawa State Government, 2008).
The state population as at 2006 is put at 1,863,275. It is made up of 945,556 males
and 917,719 females (NPC, 2006). It consists of 30 ethnic groups each with a distinct
heritage. Among the major tribes are: Alago, Eggon, Egbira, Gbagyi, Gwandara, Migili,
Fulani, Hausa, Kanuri, Tiv, Afo, Mada, Gade, Basa, Agatu Jukin, etc. The state is
structured into three Agricultural Zones (that is, Nasarawa State Agricultural
Development Programme) and 13 local government areas namely: Central Agricultural
Zone made up of Akwanga, Wamba, Nasarawa Eggon and Kokona Local Government
Areas; Southern Agricultural Zone consist of Lafia, Doma, Awe, Keana and Obi Local
Government Areas; Western Agricultural Zone comprises of Keffi, Karu, Nasarawa and
Toto Local Government Areas. The state is accessible through Benue state to the South
and Kogi State to the West, the Federal Capital Territory (FCT), Abuja to the North –
43
West, Kaduna and Plateau States to the North – East, and Taraba state to the South – East
(NSG, 2008).
Alluvial soils are found along the flood plains which are always swampy in nature
due to availability of water all the year round. The forest soils are rich in humus while the
sandy and laterite soils which are found in most parts of the state are very good for crop
production. Major crops suitable to the state ecological conditions and are produce in
large quantity are: Cassava, yam, sesame, melon, rice, maize, sorghum, soybean, cowpea,
ginger, sugarcane, cashew, mango, palm kernel and vegetables.
Nasarawa state is also endowed with abundant solid mineral resources like
Granites, Clay, Barite, Salt, Limestone, Copper Ore, Marble, Tantalite, Mica, Kaolin etc.
3.2 Sampling Technique
A multi-stage sampling technique was used for selecting respondents for this
study. The first stage of sampling involved random selection of two local government
areas from each of the three Agricultural Zones of the State. In the second stage of
sampling, two communities were purposively selected from each of the six local
government areas sampled. This gave a total of twelve communities selected across the
state. The reason for purposive selection of the communities was to identify and select
the two major sesame producing communities in each of the Local Government Areas.
The lists of sesame farmers were collected from the office of Nasarawa State Agricultural
Development Programme located in each of the Local Government Areas. From the lists,
sesame farmers were categorized into organic and conventional farmers based on pre-
field surveyed and definitions of the two terms mentioned in the background of study.
The final selection of respondents was randomly done. Five organic and five
44
conventional farmers were randomly selected from each of the communities. Thus, the
sample size for this study is one hundred and twenty (120) sesame farmers; made up of
60 organic and 60 conventional farmers.
Table 2: Designed Sampling Structure
Nas. St. Agric. Devt
Prog Zones (NADP)
Sampled
Local Govt.
Areas
Sampled
communities
Number of Farmers
selected
a. Central Agric. Zone i. Wamba
ii. Kokona
1. Messange
2. Marhei
3. Garaku
4. Basa
5 organic and 5
conventional farmers.
“ “
“ “
“ “
b. Western Agric. Zone iii. Toto
iv. Nasarawa
5. Karmo
6. Gadabuke
7. Laminga
8. Mararaba Udege
“ “
“ “
“ “
“ “
c. Southern Agric. Zone v. Keana
vi. Doma
9. Kadarko
10. Keana
11. Agbashi
12. Doma
“ “
“ “
“ “
“ “
3.3 Method of Data Collection
The data for the study were obtained from both primary and secondary sources.
The primary data for 2008/2009 cropping season were collected through field surveyed
by the researcher using structured questionnaire/interview schedule with the help of
volunteer extension staff of the NADP from each of the Agricultural Zones.
45
Types of data collected. The primary data focus on input-output variables such as output
of sesame, quantity and type of farm inputs used:- seeds (improved or local) ,fertilizers
(animal dung or NPK/Urea), pesticides (neem extracts or synthetic), labour, land area
cultivated and farming practices as well as farmers’ socio-economic characteristics like
household size and sex, educational status, farming experience, major occupation, access
to agricultural loans, method of land acquisition, marital status, age, etc.
Secondary data were obtained from existing publications of Central Bank of
Nigeria, World Bank, Nasarawa State Government, Journals, Textbooks and other
published and unpublished materials relevant to the study.
3.4 Method of Data Analysis
The data for this study were analyzed using both descriptive and inferential
statistics. Objectives i, ii, and vi were analyzed with descriptive statistical techniques like
mean, percentage, frequency distribution, ranking, standard deviation and coefficient of
variations. Objective iii was realized by total factor productivity analysis. Multiple
regression (ordinary least squares method) was used to analyzed objective iv. Objective v
was satisfied using gross margin analysis.
3.4.1 Total factor productivity estimate. The TFP was estimated for organic and
conventional sesame enterprises using the Key and Mcbride (2003) and Fakayode et al ;
(2008), approach as follows:
AVCTVCYTFP 1
Where; TFP = Total Factor Productivity, Y= quantity of output (kg)
AVC= Average variable cost (₦)
46
3.4.2 Factors influencing TFP. These factors are represented in the linear regression
equation as follows:
TFP = b0 + b1X1 + b2X2 +b3X3 ------------------------b8X8 +
where; TFP = total factor productivity Farm size in hectare (X1), Seeds in kilogram (X2),
Labour in man-hour (X3), Educational status in year (X4), Fertilizers (chemical or
organic) in kilogram (X5), Pesticides (natural or synthetic) in litre (X6), Household size
in number (X7) and Farming experience in year (X8).
b0 = constant
b1- b8 = parameter estimate (coefficients)
= Error term
The following forms of regression equations were tried and the model that gives the best
fit was chosen as the lead equation based on R2 estimates, the standard error values, sign
of coefficients and significant of the t-value.
ii) Semi – log form
TFP = b0 + b1 log X1 + b2 logX2 ----------------------------b8 log X8 +
iii) Double log form
log TFP = b0 + b1 log X1 +b2 logX2 -----------b8logX8+
These were estimated for both organic and conventional farms.
3.4.3 Gross margin analysis
Gm = G1 – TVC
Where;
Gm = gross margin (N/ha)
GI = gross income (N/ha)
47
TVC = total variable cost (N/ha) which include:
Seeds (N/kg); labour (N/man hour); fertilizers (animal dung or NPK/Urea) (N/kg) and
pesticides (natural or synthetic) (N/lt).
This was estimated for both organic and conventional farms.
3.4.4 Student t-test (for testing hypothesis i)
Where,
gX = mean of total factor productivity of organic sesame crop production
cX = mean of total factor productivity of conventional sesame production.
2cS = variance of TFP in conventional sesame production 2gS = variance of TFP in organic sesame production
ng = number of respondents (organic farmers)
nc = number of respondents (conventional farmers)
Level of significance = 0.05
3.4.5 Chow Test (for testing hypothesis ii)
According to Koutsoyiannis (1977), chow test can be calculated as follows:
F* = {e2p (e21 + e2
2 )}/k ____________________ (e2
1 + e22 )/ (n1+n2-2k)
Where; F*= Observed F-test (as suggested by G.C.Chow) e2p=Sum of square residual of pooled function e2
1 =Sum of square of n1 observation
c
c
g
g
cg
nS
nS
XXt22
48
e22 =Sum of square of n2 observation
K= Degree of freedom(number of b’s, including the intercept bo) n= Number of observation from organic farm n2=Number of observation from conventional farm
3.4.6 Student t-test (for testing hypothesis iii)
t
c
c
g
g
cg
nS
nS
XX22
Where t = test
cX = mean of farmers income from conventional sesame crop production
gX = mean of farmers’ income from organic sesame crop production.
Sc2 = variance of farmers’ income from conventional sesame crop production
Sg2 = variance of farmers’ income from organic sesame crop production
nc = number of the respondents (conventional farmers).
ng = number of the respondents (organic farmers)
level of significance = 0.05
49
CHAPTER FOUR
4.0 RESULTS AND DISCUSSION
4.1 Socio Economic Characteristics of Sesame Farmers
Sex. Sesame production in the state is dominated by male farmers. Table 3 shows that
both systems of sesame production are dominated (92% for organic and 80% for
conventional) by male farmers. The women farmers are largely involved in sesame
processing and marketing.
Age. The age of the farmers to a large extent affect their labour productivity and output.
It can also influence the adoption of innovation in traditional farming (Adewumi and
Omotosho, 2002). Table 3 shows that the bi- modal age brackets for organic farmers were
21-32 and 45-56 years, while the modal age bracket for conventional sesame farmers was
33-44 years. The mean age for both categories of farmers was 40 years. This implies that
sesame production is handled by active adults who placed much interest in the high crop
yield and profit maximization. The probable reason for the bi-modal age brackets for
organic farmers is that young adult farmers were very much practicing organic farming as
elderly farmers.
Marital status. Table 3 shows that married people constitute 97% of organic farmers and
98% of conventional farmers. The unmarried young adult farmers were more involved in
providing labour on hired basis for sesame production instead of owning the sesame
farms.
Household size. Household size is an important factor in the availability of family
labour. However, the members of the household, particularly the young adults were
mostly engaged in menial jobs so as to supplement the household heads’ contribution in
50
running the household instead of providing the family labour. The mean household size
for organic farming households was 9 members as against 12 members for conventional
farming households. Even though the mean household size is large for both categories of
farmers, family labour utilization is low for both them. This could be as a result of
engagement of young adults in menial jobs, schooling and rural-urban migration.
Table 3: Socio-Economic Characteristics of Sesame Farmers Organic sesame farmers Conventional sesame farmers Variables Frequency Percentage Frequency Percentage Sex: Male Female Total
55 05 60
92 08 100
48 12 60
80 20 100
Age: 21 – 32 33 – 44 45 – 56 57 – 68 Total Mean
21 15 21 03 60 40
35 25 35 05 100
15 23 18 04 60 40
25 38 30 07 100
Marital status: Married Single Total
58 02 60
97 03 100
59 01 60
98 02 100
Household size: 1 – 5 6 – 10 11 – 15 16 – 20 21 – 25 26 – 30 Total Mean
18 20 15 05 01 01 60 9
30 33 25 08 02 02 100
09 17 19 13 01 01 60 12
15 28 32 22 1.5 1.5 100
Educational status: Illiterate Primary Secondary Tertiary Total
17 19 15 09 60
28 32 25 15 100
33 09 10 08 60
55 15 17 13 100
F. Experience: 3 – 8 9 – 14
23 15
38 25
24 13
40 22
51
15 – 20 21 – 26 27 – 32 Total Mean
18 02 02 60 12
31 03 03 100
18 04 01 60 12
30 06 02 100
L. Acquisition: Inherited land Communal land Share cropping Total
51 07 02 60
85 12 03 100
45 07 08 60
75 12 13 100
F. Implement: T. Implements (hoe & cutlass)
56
93
48
80
Combination of trad. Implements and tractor Total
04 60
07 100
12 60
20 100
Cooperative membership: Yes No Total
27 33 60
55 45 100
32 28 60
53 47 100
Seed variety: Improved seed variety Local seed variety Total
38 22 60
63 37 100
44 16 60
73 27 100
Source of labour: Hired labour Family labour Combination of family and hired labour Total
43 07 10 60
72 11 17 100
46 06 08 60
77 10 13 100
Source: Field Survey, (2009).
Educational status. Education is known to facilitate farmers’ understanding and the use
of improved crop production technologies. Table 3 shows that 28% of organic farmers
were illiterate as against 55% of conventional farmers. This implies that there were more
52
literate farmers (72%) involved in organic sesame farming than conventional sesame
farming (45%). With this high level of literacy, organic farming techniques could be
relatively easily understood and practiced in the state, thus enhancing the efficiency of
utilization of resources in sesame production.
Farming experience. The farmers’ farming experience is a measure of level of expertise
in the management of farm resources for greater efficiency. Table 3 shows that 76% of
organic farmers and 60% of conventional farmers have been cultivating sesame crop for
over 8 years. The mean farming experience by both farmers was 12 years. This implies
that organic sesame production attracts farmers with more farming experience,
Method of land acquisition. Most farmers (85% organic and 75% conventional)
acquired their sesame farmland through inheritance. This explains why most farm lands
were fragmented and scattered. This could serve as disincentive to large-scale sesame
production in the state. Other methods used in acquiring sesame farmlands in the state
include communal land and share cropping (Table 3). These constituted 12% and 3%
respectively for organic farmers and 12% and 13% for conventional farmers respectively.
Types of farm implements used. Table 3 shows that most sesame farmers (93% organic
and 80% conventional) employed traditional implements (hoes and cutlasses) exclusively
for farming operations. This explains why more manhours (327/ha for organic farms and
283/ha for conventional farms) were spent on farming operations in the state. This could
be responsible for higher cost of labour compared to farming operations performed by
mechanical means.
Membership in cooperative societies. The belonging of farmers to agricultural
cooperatives can enhance their access to credit, improved inputs and general information
53
that can improve productivity and output. Most sesame farmers (55% organic and 53%
conventional) belong to one form of cooperatives or the other. While 45% of organic and
47% of conventional farmers did not belong to any form of cooperatives (Table 3).
Seed variety. The variety of seed planted by the farmers can account for quantity of yield
harvested. In most instances, improved seed varieties yield higher output than local
variety provided certain conditions are met. Table 3 shows that organic sesame farmers
used more local variety of sesame seed than conventional farmers. About 73% of
conventional farmers used improved variety of sesame as against 63% used by organic
sesame farmers.
Source of labour. Table 3 shows that most sesame farmers (72% organic and 77%
conventional) used hired labour to perform various farm operations. Only 11% of organic
farmers and 10% of conventional farmers engaged the services of family labour
exclusively. Those that combined services of both hired labour and family labour
constituted about 17% of organic farmers and 13% conventional farmers.
4.2.1 Organic Farming Practices
The sustainability of agricultural productivity in organic farming depends largely
on environmentally friendly farming practices like the use of organic manure, green
manure, natural pesticide and on biodiversity. Table 4 shows that the common organic
sesame farming practices identified are crop rotation with legumes, application of animal
manure and the use of natural pesticides. The natural pesticides commonly used in the
area include a solution made from neem (Azadirachta indica) for protecting the sesame
plants from insect attack, application of dried pepper as a store-pesticide and ashes. Other
54
common organic farming practices identified are the use of green manure, cover cropping
and tillage and cultivation.
Table 4: Distribution of Organic Sesame Farmers According to Farming Practices
Organic farming practices Frequency* Percentage (%)
Crop rotation with legumes 60 100
Green manuring 42 70
Use of animal manure 60 100
Use of natural pesticides 60 24
Application of compost manure 0 0
Mulching 0 0
Cover cropping 27 37
Tillage and cultivation 06 10
Source: Field Survey, (2009)
* Multiple responses were considered; therefore total frequency is more than sample size.
4.2.2 Conventional Farming Practices
The conventional farming practices are reported to be inimical to the agro-
ecosystem at long run. However, in the present, the conventional farming practices
ensure relatively higher yield and return to farmers. The common conventional farming
practices identified are the use of synthetic agrochemicals; namely chemical fertilizer like
N.P.K and Urea, and pesticides and/or herbicides. Burning of crop residues on the farms
as well as intensive tillage are common practices. There were few cases of monoculture
involving palm trees, banana and cashew (Table 5). The practice of conventional
55
agriculture all tend to compromise future productivity of farm land in favour of higher
yield in the present.
Table 5: Distribution of Conventional Sesame Farmers According to Farming
Practices.
Conventional Farming Practices Frequency* Percentage (%)
Monoculture 10 16
Intensive tillage 25 42
Use of chemical fertilizer 60 100
Use of synthetic pesticide 60 100
Burning of crop residues on the farm 40 67
Source: Field Survey, (2009).
* Multiple responses were considered; therefore total frequency is more than sample size.
4.3 Input and Output Levels of Sesame Farms Per Hectare
Seed. The average quantity of seed planted per hectare by organic sesame farmers was
7kg/ha, while 7.7kg of seed per hectare was planted by conventional farmers (Table 6).
Hence, these seeding rates are slightly higher than recommended seed rate of 5kg/ha
(German Technical cooperation, 2009), suggesting that both categories of these farmers
are probably over using seeds.
Labour. Table 6 shows that average man- hours spent on various farm operations varied
between organic and conventional sesame farms. On organic farms, the average man
hours spent was 327 per hectare as against 283 man hours per hectare spent on
conventional farms. Thus, the organic sesame farm is more labour intensive than the
56
conventional sesame farm. This result agrees with World Bank (2005), that organic
production systems often use more labour because they need additional soil conservation
measures – such as manual control of weeds, pests and diseases, and applying large
volumes of organic fertilizers.
Table 6: Input and output Levels of Sesame Farms
Organic sesame farms Conventional sesame farms
Variables Max. Min Mean SD CV
(%)
Max Min Mean SD CV
(%)
Output (kg) 1000 167 506 190 38 1500 188 552 235 43
Seed (kg) 18 4 7 2.6 37 13 4 7.7 2.3 30
Labour(man hr) 1064 96 327 211.7 65 659 85 283 131.9 47
Pesticide (litre) 12 1.1 5.6 2.3 41 8 0.30 1.9 1.6 84
Fertilizer (kg) 5000 167 1381 1063 77 400 12.5 69 75 107
Source: Field Survey, (2009)
SD: Standard deviation, CV: Coefficient of variation
Fertilizers. The average quantity of organic fertilizer (animal manure) applied on organic
farms was 1381 kg/ha. This quantity falls short of the recommended rate of 5 tons of
organic manure per hectare (GTZ, 2009). On the other hand, the average quantity of
chemical fertilizer applied on conventional farms was 69 kg/hectare (Table 6), which is
much below the recommended rate of 100kg per hectare (RMRDC, 2004).
Pesticides. Table 6 shows that average litre of natural pesticide (neem extracts) applied
by organic farmers was 5.6 per hectare as against 1.9 litre per hectare applied by
conventional farmers. The natural pesticide is used in protecting sesame plants against
insect pests. The two type of pesticide used by conventional farmers were herbicides and
insecticides (e.g Karate). The 1.9 litre of insecticide applied per hectare is higher than the
57
recommended rate of 1 litre per hectare (GTZ 2009), suggesting that pesticides is over
used.
Output. The average quantity of yield per hectare realized on organic sesame farms was
506kg as against 552kg per hectare realized on conventional farms (Table 6). This
implies that on average, additional 46kg per hectare is realized by conventional farmers
over organic farmers. This result confirms Erdemir and Zeki (2005), that raisin yield of
the organic farm was 8% lower than that of the conventional farms. The general average
output/hectare of sesame observed is lower than the 600kg per hectare estimated average
output for the state (GTZ, 2009).
4.4 Gross Margin Analysis of Sesame Farmers
Gross returns. The gross returns was computed for every farmer by multiplying Gross
yield by unit price. The unit price varied widely from N100 to N300 on the average. The
unit price was at lowest amount (N100) during harvesting period (around January, 2009)
and rose steadily to its peak (N300) (around August, September, 2009) at planting season.
The average gross returns per hectare realized by both organic and conventional farmers
were N93,828 and N100,875 respectively (Table 7).
Total variable cost The total variable cost was computed by adding all the variable costs
(that is costs of seed, fertilizer, pesticides and labour) incurred in production of sesame by
every farmer. Table 7 shows that average total variable cost per hectare incurred by
organic and conventional farmers were N31419 and N36308 respectively.
58
Table 7: Gross Margin Analysis of Sesame Farmers
Organic Sesame farmer Conventional Sesame farmers
Variables Av.
Qty/ha
Av.
Unit
Price
Value
(N/ha)
Av.
Qty/ha
Av.
Unit
price
Value
1. Gross Returns:
Average yield (kg)
506 185 93828 552 183 100,875
2. Inputs:
Seed (kg)
Fertilizer (kg)
Pesticides (Lt)
Labour (man hour)
7
1381
5.6
327
235
1
131
85
1643
1228
733
27815
7.7
69
1.9
283
252
59
1243
97
1948
4,078
2361
27921
3. Total variable cost/ha 31419 36308
4. Gross margin/ha 62409 64567
Source: Field Survey, (2009)
Gross margin: The gross margin was computed by subtracting the total variable cost
from gross return for every farmer. Table7 shows that average gross margin per hectare
realized by both organic and conventional farmers were N62409 and N64567
respectively. Though, on the average basis, conventional farmers earn more income than
organic farmers emanating from higher yield per hectare, the difference in the amount of
income earned is not statistically significant. The average rate of return for organic and
conventional sesame enterprises were N3 and N2.8 respectively. This implies that on
average, for every N1 investment, N2 profit is made by the organic sesame farmer as
against N1.8 profit by the conventional sesame farmer. Thus, Internal Rate of Returns
(IRR) is higher with organic sesame enterprise than conventional sesame enterprise. This
result confirms earlier research result by Kathleen et al; (2008), that revenues generated
from organic corn crops increased average revenue by a factor of 1.67 over conventional
59
corn, while organic soybean revenues were 2.32 times greater than conventional soybean
revenue. The production cost per kg was N62 for organic farms which is lower than N68
for conventional farms.
4.5 Total Factor Productivity Estimates
Tables 8 and 9 show that on the average, the TFP estimates for the organic farms (1.9)
with 55 coefficient of variation was higher than that of conventional farms (1.7) with 82
coefficient of variation. This result follows since the average variable cost is lower in
organic sesame farms than conventional sesame farms. The higher average TFP recorded
for organic farms show that organic sesame enterprise is more productive than
conventional farms. About 37% of organic sesame farms have over 1.99 TPF level, more
than the 23% recorded for conventional sesame farms. The higher the value of TPF, the
lower the value of AVC and the more productive is the farm. However, the difference in
TPF levels (that is productive levels) between the two different enterprises (organic and
conventional sesame farms) is insignificant statistically.
Table 8: Percentage Distribution of Total Factor Productivity Indices for Sesame
Farms.
Organic farms Conventional Farms
TFP Indices Frequency Percentage (%) Frequency Percentage (%) 0.6 – 1.9 2 – 3.3 3.4 – 4.7 4.8 – 6.1 > 6.1 Total
38 18 2 2 0 60
63 31 03 03 0 100
46 11 02 0 01 60
77 18 03 0 02 100
Source: Data Analysis, (2009)
60
Table 9: Total Factor Productivity Indices for Sesame Farms.
Organic farms Conventional farms
Variable Max Min Mean SD CV (%) Max Min Mean SD CV (%)
TFP 5.8 0.60 1.9 1.05 55 11 0.60 1.7 1.4 82
Source: Data Analysis, (2009)
4.6 Factors of Total Factor Productivity (TFP)
The results of OLS regression estimate on the hypothesized determinants of
productivity level namely farm size, seed, labour, educational status, fertilizer, pesticide,
household size and farming experience are presented in tables 9 and 10.
4.6.1 Regression Estimates for Factors of Total Factor Productivity of Organic
Sesame Farms.
The lead equation for determinants of TFP for organic farms was the Double log
function. Table 10 shows that coefficients of pesticide, household size, farm size, farming
experience and education have expected positive apriori signs. Increase in any of these
coefficients will increase the productivity level of organic farms, as they contribute little
or no cost to the total production cost. Increase in farmer’s educational status and farming
experience will definitely enhance his management skill and hence his productivity.
The coefficients of seed, labour and fertilizer were negative. This result follows
since seed and labour were over-utilized, more productivity can still be attained when
their quantity are reduced. The negative coefficient of fertilizer arose from the fact that
61
where high concentration of green manure exist or where sesame is planted in rotation
with legumes, decrease in the quantity of animal manure can still increase or improve
Table 10: Regression Estimates for Factors of Total Factor Productivity of Organic
Sesame Farms – Double Log function.
Variables Coefficients Standard Error T-value
Constant 2.937 1.023 2.872***
Farm size X1 0.891 0.232 3.831***
Seed X2 -0.475 0.175 -2.715***
Labour X3 -0.587 0.127 - 4.605***
Education X4 0.178 0.149 1.194NS
Fertilizer X5 - 0.001 0.073 - 0.009NS
Pesticide X6 0.162 0.160 1.013NS
Household size X7 0.278 0.118 2.360**
Farming experience X8 0.258 0.105 2.467***
Source: Data analysis, (2009)
F-value 5.963**
R2 – value 0.584
***: Significant at 1% level of probability.
**: Significant at 5% level of probability. NS: Not significant.
productivity level of the sesame farm. The variable coefficients for farm size, seed,
labour and farming experience were significant at 1% level of probability. Household
size was significant at 5% level of probability. The variable coefficients for education,
fertilizers and pesticides were insignificant. The result implies that farm size, seed,
labour, farming experience and household size influence productivity level of organic
sesame farms.
62
The R2 value for double log function was 0.584. This implies that hypothesized
determinants included in the regression model accounted for about 58% variations in the
productivity level recorded in the organic sesame enterprise. The F-value was 5.963 and
significant at 5% level of probability. This means that the joint effects of variables
included in the regression model on the productivity level of organic sesame farms were
significant.
4.6.2 Regression Estimates for Factors of Total Factor Productivity of
Conventional Sesame Farms.
The lead equation for determinants of TFP level of conventional sesame farms was a
linear function. Table 11 shows that the variable coefficients for farm size, education and
farming experience have expected positive aprori expectations. Increase in these
variables can enhance productivity level of conventional sesame farms. The coefficients
for seed, labour, fertilizer, pesticide and household size were negative. Since seed, labour,
and pesticide were over-utilized by conventional sesame farmers, their decrease in
quantity can increase the productivity level of conventional farms. The negative
coefficient of fertilizer arose from the fact that high quantity of local variety was used by
conventional farmers. The local variety of sesame seed does not respond well to chemical
fertilizer, especially where the soil fertility is high. In such condition, productivity can be
increased even when the quantity of chemical fertilizer is reduced.
63
Table 11: Regression Estimates for Factors of Total Factor Productivity of
Conventional Sesame Farms – Linear Function.
Variables Coefficients Standard Error T-value
Constant 1.111 0.410 2.70***
Farm size X1 0.944 0.144 6.568***
Seed X2 -0.042 0.23 -1.847*
Labour X3 -0.001 0.000 -2.302**
Education X4 0.006 0.016 0.337NS
Fertilizer X5 - 0.002 0.001 -1.821*
Pesticide X6 -0.075 0.042 -1.795*
Household size X7 -0.006 0.026 -0.241NS
Farming experience X8 0.019 0.021 0.885NS
Source: Data Analysis, (2009)
F-value 9.154**
R2 – value 0.589
***: Significant at 1% level of probability.
**: Significant at 5% level of probability. * Significant at 10% level of prob.
The variable coefficients for farm size, and labour were significant at 1% and 5% levels
of probability respectively, while coefficients of seed, fertilizer and pesticide were
significant at 10% level of probability. This implies farm size, labour, seed, fertilizer and
pesticide influence the productivity level of conventional sesame farms. The coefficient
of educational status, household size and farming experience were not significant and
hence they have no influence on productivity level. The R2 value for the linear function
was 0.589, indicating that the hypothesized variables included in the regression model
accounted for about 59% variations in the productivity level of conventional sesame
farms. F-value was 9.154 and significant at 5% level of probability. This implies that the
64
joint effects of variables included the regression model on total factor productivity of
conventional sesame farms were significant. The significant influence of land, labour and
fertilizer on TFP is in conformity with result of Fakayode et al (2008).
4.7 Hypotheses Testing
The results of hypothesis testing are shown in Tables 12, 13 and 14. The results
confirmed that there was no significant difference between productivity level of organic
and conventional sesame farms; the difference in amount of income earned from both
enterprises were insignificant; and, there was no significance difference between the
effects of determinants on TFP for both enterprises.
65
Table 12: Result of t-test Comparing Productivity of Organic and Conventional
Sesame Farms
c
c
g
g
cg
nS
nS
XX22
t* <t 0.05
Thus, null hypothesis is accepted
Source: Data Analysis, (2009).
Computation Value
gX 1.9
cX 1.7
S2g 1.1 2cS
2.0
ng 60
nc 60
t*
= 1
66
Table 13: Result of Chow Test Comparing the Influence of Identified Factors on
TFP of Organic and Conventional Sesame Farms.
Computation Value
Σe2p 10.6
Σe21 4.7
Σe22 47
n1 60
n2 60
K 9
F* = Σe2p – (Σe22 + e2
2) /k
(Σe21 + Σe22/(n1 + n2 – 2k)
Thus F* < F0.05 and hence we accept
null hypothesis.
= - 9.2
Source: Data Analysis, (2009)
67
Table 14: Result of t-test Comparing Incomes from Organic and Conventional
Sesame Farms.
Source: Data Analysis, (2009)
4 .8 Constraints to Sesame Production
The major constraints to increased sesame production confronting both categories
of farmers are shown in table 15 and 16. Poor access to credit facility, poor access road
network and low market price for sesame grains have been identified as major constraints
to sesame production. High cost of chemical fertilizer, shortage of chemical and organic
fertilizer also constituted major constraints to sesame production. Scarcity of improved
seed variety and high cost of synthetic pesticide also pose constraints to sesame
production.
Computation Value
gX 62,409
cX 64,567 2gS
2003905225 2cS
2270905225
ng 60 nc 60 T* < t 0.05. Thus, null hypothesis is accepted
= - 0.00003
c
c
g
g
cg
nS
nS
XXt22
*
68
Table 15: Constraints to Organic Sesame Production
Constraints Frequency Rank
i. Poor access to credit 53 1st
ii. Poor access road network 44 2nd
iii. Low market prices for sesame grain 39 3rd
iv. Shortage of organic fertilizer 18 4th
v. Scarcity of improved sesame seed 09 5th
vi. Poor storage facility 08 6th
vii. Pests and diseases 05 7th
viii. High cost of organic fertilizer 04 8th
Total 180*
Source: Field Survey, (2009)
* Multiple choices were allowed hence total frequency exceeded sample size
69
Table 16: Constraints to Conventional Sesame Production.
Constraints Frequency Rank
1. High cost of chemical fertilizer 54 1st
2. Poor access to credit 53 2nd
3. Poor access road net work 35 3rd
4. Shortage of chemical fertilizer 26 4th
5. Low market price for sesame grain 17 5th
6. High cost of synthetic pesticides 17 5th
7. Scarcity of improved seed 09 7th
8. Poor storage facility 09 7th
9. Pest and disease 03
Total 223*
Source: Field Survey, (2009)
* Multiple choices were allowed hence total frequency exceeded sample size
70
CHAPTER FIVE
4.0 SUMMARY, CONCLUSION AND RECOMMENDATIONS
5.1 Summary
The study was designed to compare the economics of organic and conventional
sesame production systems in Nasarawa State, Nigeria.
The broad objective was to conduct a comparative economic analysis of organic
and conventional sesame production systems in Nasarawa State. Specifically, the study
intended to achieve the followings: describe socio-economic characteristics of organic
and conventional farmers, identify organic and conventional farming practices, identify
input and output levels in both farms, estimate productivity levels of organic and
conventional sesame farms, identify the determinants of productivity level in both farms,
determine enterprise profitability in both farms and identify constraints to increased
sesame production.
Multi-stage sampling was used to select 120 farmers; made up of 60 organic and 60
conventional sesame farmers. Data were collected based on 2008/9 cropping season
through structured questionnaire. Data were analyzed using descriptive statistics, TFP
estimate, OLS regression analysis and gross margin analysis.
The results show that men and married farmers dominated production of sesame,
and they were mostly adult. The mean household size for organic farmers was 9 members
compared to 12 members for conventional farmers. They were more literate farmers
(72%) in organic farming than conventional farming (45%). Over 76% of organic farmers
and 60% of conventional farmers have been farming sesame crop for over 8 years. The
mean of farming experience was 12 years for both farmers. Most farmers (85% organic
71
and 75% conventional) acquired sesame farm land through inheritance. Traditional
implements like hoe and cutlasses were employed exclusively for farming sesame by
93% of organic and 80% of conventional farmers. Most farmers (55% organic and 53%
conventional) belong to one form of agricultural cooperatives or the other. More of
conventional farmers used improved seed (73%) than organic farmers (63%) and Hired
labour was mostly patronized by both organic (72%) and conventional (77%) farmers.
The common organic farming practices were crop rotation with legumes,
application of animal manure and local pesticide (neem solution) as well as green
manure. On the other hand, the use of chemical fertilizer (e.g. NPK, urea), insecticide
(e.g. Karate and cymbush), burning of crop residues and intensive tillage were common
practices among conventional farmers.
A total of 159 and 169 hectares were put under production of sesame by both
organic and conventional farmers. 2.6 hectares per organic farmer and 2.8 hectares per
conventional farmer were the mean hectares cultivated by both farmers. The average
quantities of seed planted per hectare by both farmers were 7kg (organic farmers) and
7.7kg (conventional farmers). On organic farm, average man-hours spent was 327 per
hectare compare to 283 man-hours per hectare spent by conventional farmers. An average
of 1381kg of animal manure was used per hectare as against 69kg per hectare of chemical
fertilizer. The litre of natural pesticide used per hectare was 5.6 compared to 1.9 litre per
hectare of synthetic pesticides. The average output per hectare of organic and
conventional farms were 506kg and 552kg respectively.
The gross returns from organic and conventional farms per hectare were N93838
and N100875, while total variable costs from organic and conventional farms per hectare
72
were N31419 and N36308 respectively. The gross margins from both farms were N62409
per hectare of organic farm and N64567 per hectare of conventional farm. The Internal
Rate of Returns was higher in organic farms with N2 as against N1.8 in conventional
farms.
On the average, TFP estimates for organic farms (1.9) was higher than that (1.7)
recorded for conventional farms. This implies that organic farms were more productive
than conventional farms on the average.
The result of regression model (Double log function) for determinants of TFP of
organic farms indicated that farm size, seed labour, farming experience and house hold
size influence productivity level of organic farms positively except for seed and labour.
The R2 value was 0.584 and F-value was 5.963 and was significant at 5% level of
probability, while the result of regression model (linear function) for determinants of TFP
of conventional farms showed that farm size, labour, seed, fertilizer and pesticide
influence productivity level of conventional farms negatively except for farm size . The
R2 value was 0.589 and F-value was 9.154 and was significant at 5% level of probability.
The identified major constraints to increased sesame production confronting both
farmers were poor access to credit facility, poor road network to the villages, low market
price, high cost of chemical fertilizer, and shortage of chemical and organic fertilizers.
Others include non availability of improved seed as well as high cost of synthetic
pesticide.
73
5.2 Conclusion
Based on the findings of the study, the difference in gross margin earned between
organic and conventional farms was insignificant. Similarly, the difference in
productivity level between organic and conventional farms was not significant. The
effects of determinants on total factor productivity (productivity level) between organic
and conventional farms were similar. Therefore, organic sesame farming, which has the
advantage of ensuring sustainable farm productivity and income should be encouraged
and incorporated into agricultural policy and programme of the state as a means of
achieving food and income security.
5.3 Recommendations
Based on the findings of the study, the following recommendations are made.
1. In order to ensure sustainable sesame production, organic sesame farming
should be encouraged by the government through appropriate policy.
2. Sesame farmers’ access to credit is very poor in the state. Therefore, to ensure
wider cultivation of the crop, credit facility should be channeled to the real
farmers through cooperative organizations. Farmers should be encouraged to
form viable agricultural cooperatives.
3. Feeder roads should be constructed and those in deplorable conditions should
be repaired in the rural areas. This will facilitate movement of sesame produce
from rural areas to town and urban markets and there by reducing the glut and
ensuring a better price for the produce.
4. The present government policy of buying excess produce from farmers during
harvesting season at higher prices should be extended to rural communities
74
where farming is taking place. This will reduce price fluctuation and making
farmers to earn more income.
5. Sesame farmers should be assisted with inputs that are essential to farming
activities like improved seed, tractor, organic fertilizer etc.
6. Sesame farmers should be guided on appropriate quantity of inputs use per
hectare by extension agents to avoid wastage.
75
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