INJIBARA UNIVERSITY

COLLEGE OF AGRICULTURE, FOOD AND CLIMATE SCIENCE

DEPARTMENT OF PLANT SCIENCE

REVIEW ON ROLE OF ORGANIC FARMING ON SOIL FERTILITY

AND CROP PRODUCTIVITY IN ETHIOPIA

Senior Seminar Paper Submitted to Department of Plant Science for in

Fulfillment of the Course Senior Seminar Paper in Plant Sciences.

Complied BY:

Name ID. No.

1. Sanchoel Belete Inusr/0887/13

2. Wudinesh Yamrot INUSR/0825/13

Advisor: Walelign Bitewulign (Msc in Soil science)

January 16, 2025

Injibara, Ethiopia
 ACKNOWLEDGEMENT

First of all, we would like to thank the almighty God for keeping us safe and healthy
from the start to the end of this work. Our heartfelt thanks also go to our advisor Mr.
Walelign for his unreserved advice and constructive feedbacks during the preparation of
this senior seminar work. We thank the department of Plant Sciences and the staff in
general for their respective overall support. Last but not least, we would like to take this
opportunity to acknowledge our families for their continuous economical and moral
supports.

i
ACRONOMY AND ABBREVIATIONS

ATP Adenine Tri Phosphate

BNF Biological Nitrogen Fixation

FAO Food and Agricultural Organization

FYM Farm Yard Manure

INM Integrated Nutrient Management

NPK Nitrogen, Phosphorus, Potassium

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 TABLE OF CONTENTS

ACKNOWLEDGEMENT.......................................................................................................I

ACRONOMY AND ABBREVIATIONS..............................................................................II

ABSTRACT............................................................................................................................IV

1. INTRODUCTION................................................................................................................1

1.1 OBJECTIVES...................................................................................................................2

1.2 Specific objective.............................................................................................................2

2. THE ROLL OF ORGANIC FARMING ON SOIL FERTILITY IMPROVEMENT...3

2.1 Effect organic Farming on Physical property of soil........................................................5

2.2 Effect organic Farming on Chemical property of soil......................................................6

2.3 Effect organic Farming on Biological property of soil....................................................7

4. CHALLENGE OF ORGANIC FARMING ADOPTION IN ETHIOPIA......................9

4.1 Lower productivity...........................................................................................................9

4.2 Requires skill....................................................................................................................9

4.3 Labor-intensive.................................................................................................................9

5. SUMMARY AND CONCLUSION...................................................................................11

6. REFERENCES...................................................................................................................12

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 ABSTRACT

Soil fertility is one of the major factors limiting crop production and productivity in
smallholder farming, particularly in tropical regions. Organic farming is the production
system that avoids or largely excludes the use of synthetic fertilizers, pesticides, growth
regulators and livestock feed additives. To the maximum extent feasible, organic farming
system rely on crop rotation, crop residues, animal manures, legumes, green manures, off-
farm organic wastes, mechanical cultivation, and mineral bearing rocks. Sustainable food
production is the most critical challenge of today’s agriculture for an ever-increasing human
population. Sustainable agriculture is successful management of resources for agriculture to
satisfy changing human needs while maintaining or enhancing the quality of the environment
and conserving natural resources. Organic farming improves the soil fertility thereby
improves crop yield. However organic farming has its own limitations to adopt it in Ethiopia.
Therefore, the objective of this seminar paper is to review organic based management
options for sustainable soil and crop production and soil productivity and compile
information for the readers like researchers, university lectures, students, farmers and
scientific communities to better understand the role of organic agriculture for sustainably of
soil and crop productivity.

Key Words: Legumes, Manures, organic farming, Soil fertility

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 1. INTRODUCTION
Sustainable food production is the most critical challenge of today’s agriculture for an ever
increasing human population. Sustainable agriculture is successful management of resources
for agriculture to satisfy changing human needs while maintaining or enhancing the quality of
the environment and conserving natural resources (TAC/CGIAR, 1988). Soils are an integral
component of agriculture and serve as medium for numerous biological, chemical and
physical processes. Over-burdening of the soil as a natural resource capital has always been an
issue due to its widely varied applications in the maintenance of human life activities.

Soils in Ethiopia are typically highly variable in fertility and in how they respond to inputs.
Most soil resources in Ethiopia exhibit low nutrient levels with a high tendency towards
nutrient loss due to their fragile nature. Declining soil fertility is fundamental obstruction to
agricultural growth and major reasons for slow growth in food production. Soil nutrient
depletion and likely degradation have been considered serious threats to agricultural
productivity and have been identified as major causes of decreased crop yields and per capital
food production Ethiopia (Henio and Baan ante, 2006). Therefore, Soil fertility replenishment
in Ethiopia is increasingly viewed as critical to the process of poverty alleviation (Amide T,
2003). Intensified cropping activities on available cropland resources have resulted in
alteration of their natural physical and chemical properties, changes in biotic components of
their microenvironment and an overall reduction in fertility status. Agricultural productivity in
most Ethiopian regions is 2-3times lower than the world average yield (Fraser et al., 1998)

The historical practices of organic farming is back to the movement for agricultural reforms
on the principles of self-sufficiency and economic viability of farms in which soil fertility was
to be amained through crop rotation ,careful management ,and use of animal manures. The
experimental work done on role of organic matter in soil and composting provided power full
stimuli and to investigate the link between the way food is produced, food quality and human
health, also the idea of emphasizing the role of a healthy, fertile soil in production of healthy
crops and livestock and the link with human health were persuade. The early organic
movement focused strongly on the issues of human health and promotion of soil fertility
through the use of composts and organic fertilizers (Saskatoon et al., 1994).

The use of fertilizers and pesticides has led to enormous levels of chemical building in our
environment soil, water, air, animals and even treat to our bodies or human health. Fertilizers
have a short term effects on productivity but a longer term negative effects on the

1
environment where they remain for years after leaching and running off contaminating ground
water and water bodies (Sanders, 1953). Organic farming has the capability to take care of
each of these problems. Besides, the positive effects organic farming has on the environment
and quality of food, it also greatly helps a farmer to become self sufficient in his requirements
for agro-inputs and reduce his/her costs. Organic farming aspires to a combine mixtures of
organic, environmental, social and ethical objectives (Sexton, 1989).

Bearing in mind the above consequence on environment and human health the current review
was aimed to review the importance of organic based management options for sustainable
crop production and soil productivity and compile information for the readers like researchers,
university lectures, students, farmer’s and scientific communities to better understand the role
of organic agriculture for sustainably of soil and crop productivity.

1.1 OBJECTIVES

 To Compile the information for the readers by Reviewing the effect of Organic
Farming on Soil Fertility and Crop Productivity in Ethiopia

1.2 Specific objective

 To assess the impact of organic farming practices on soil fertility and health in
Ethiopia
 To review the importance of organic farming for improving crop productivity

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 2. THE ROLL OF ORGANIC FARMING ON SOIL FERTILITY
IMPROVEMENT

Soil fertility is fundamental in determining the productivity of all farming systems

Watson, et al. and thus inseparable from food security. Soil fertility is often defined as
the soil’s ability to supply nutrients to crops but it can be defined more widely as an
ecosystem concept Swift, et al. which integrates the diverse functions of soil that
promote plant growth, including nutrient supply [12]. This broad definition is fitting as
organic farming recognizes the complexity of relationships between different
components of any farming system and that sustainability depends on the functioning of
the whole integrated system [13]. A basic concept of organic farming is that “the health
of soil, plant, animal and man is one and indivisible” Balfour, r, et al. Organic farming
systems rely on the management of soil organic matter to enhance the chemical,
biological, and physical properties of soil, in order to optimize crop production and
health . Thus, the supply of nutrients to crops, and subsequently to livestock and humans,
is the net result of a set of management decisions including rotation design, manure
management, etc., as well as soil management peruse. The central concept of soil fertility
in these systems is the use of legume-based multi-annual rotations together with the
careful use of on-farm manures Stockdale, et al.

The foundation of organic agriculture lies in the health of soil. Soil fertility management
maintains and improves soil condition and minimizes erosion. Strategies used to achieve
this include crop rotation, the use of green manures and cover crops, the application of
plant and animal matter and the application of allowable soil amendments. Nutrient
levels in soil should be regularly tested to determine the amount of nutrients required for
optimum growth of a particular crop as well as the necessary amount of manure, compost
and allowable fertilizer that should be applied. Organic farming systems rely on the
management of soil organic matter to enhance the chemical, biological, and physical
properties of soil, in order to optimize crop production and health. Thus, the supply of
nutrients to crops, and subsequently to livestock and humans, is the net result of a set of
management decisions including rotation design, manure management, etc., as well as
soil management peruse. The central concept of soil fertility in these systems is the use
of legume-based multi-annual rotations together with the careful use of on-farm manures
Stockdale, et al. Y systems, keeps biological life cycle alive and helps in sustaining
considerable levels in yield. It is mainly based on principles of restoration of soil organic

3
matter in the form of humus, increasing microbial population, skillful application of the
factors contributing soil life and health and treating manures in bio-dynamic way
Pathank RK, et al. Application of organics matter which is an important component in
organic farming, apart from improving the soil physical, chemical and biological
properties with direct impact on moisture retention, root growth and nutrient
conservation, can also reduce the cost of production in agriculture. Keeping these
benefits points in view an investigation was carried out to find out the plant nutrients
supplied through organic sources had profound effect on growth and productivity of the
crop either by acceleration of respiratory process with increasing cell permeability and
hormonal growth action or by combination of all these processes. Through their
biological decomposition processes the organic sources supply nutrients to the plants in
the available form. They are also rich in micro nutrients besides having plant growth
promoting substances viz., hormones, enzymes and humus forming beneficial microbes.
Organic sources, on application to the soil, improve the physical properties of soil such
as aggregation, aeration, permeability and water holding capacity Mukesh K, et al. which
promote growth and development of plants. It has been reported that among the organic
sources of nutrients, poultry manure proved to be the Razzaq Owayez, et al. best source
of organic manure which helped in improving physico-chemical properties (pH, EC,
organic carbon, macro and micro nutrients) of soil because of its higher analytical values
Govindarajan K, et al

Vermicompost is the method of using earthworms to transform organic waste into

nutrient rich compost. Soil earthworms play an important role in agriculture, it
decomposes dead organic litter by consuming them and release as castings. The
earthworms accelerate decomposition of plant litter and organic matter and improve soil
fertility by releasing mineral elements in the forms that are easily uptake by plants [6].
According to [6] Vermicompost contains most nutrients in plant available form such as
nitrates, phosphates, exchangeable calcium and soluble potassium .It is usually rich in
microbial populations and diversity particularly fungi, bacteria and actinomycetes. The
behavioral activity of earthworms that is feeding, burrowing and casting; modify the
physical, chemical and biological properties of organic matter and soil for plant growth
and nutrient acquisition. Due to large surface area, Vermicompost offers several micro
sites for nutrient retention and exchange and microbial activity. Inclusion of
Vermicompost organic manure in crop production is a better alternative for improving

4
 soil health; crop productivity and quality as it exert a significant positive influence on
soil properties and microbial population

Bio-fertilizer has been identified as an alternative to chemical fertilizer to increase soil

fertility and crop production in sustainable farming [8]. These potential biological
fertilizers would play the key role in productivity and sustainability of soil and also
protect the environment as ecofriendly and cost effective inputs for the farmers [8].
Organic agriculture is one of such strategies that not only ensures food safety but also
adds to biodiversity of soil [9]

2.1 Effect organic Farming on Physical property of soil

t enhanced heterotrophic bacteria, fungi in soil and increased the soil enzymatic activity
which is responsible for the conversion of unavailable to available form of nutrients
(Alvares et al. 1999). In addition to quality produce, organic farming improves the soil
organic matter (SOM) content, soil biological activity soil structure, soil fertility and soil
health and carbon sequestration compared with chemical farming (Table 1). The
characterization of physical, chemical and biological health of soil in relation to long-
term organic farming is important for managing the nutrient and water use efficiencies
for optimum soil health and plant growth. Soil physical properties Soil physical
properties get improved with organic farming due to reduced bulk density, increased soil
porosity, available water and soil organic carbon content in the surface soil layer (Cima
et al. 2015). Pramanik and Prasad (2015) also reported that in wheat-based organic
farming for 10–11 years, the bulk density was lower whereas soil water content and
porosity were higher in 0–15 cm soil layer organic wheat field than in conventional field.
Vengadaramana and Jashothan (2012) reported that addition of compost and farmyard
manures each increased the mean water holding capacity (WHC) of soil over the control.
Organically managed soils had higher organic matter content and provided a more stable
soil structure than conventionally managed soils (Papadopoulos et al. 2006). Organic
amendments increased the proportion of macro-aggregate and mean weight diameter of
aggregates in the surface soil layer (Zhang et al. 2014). Six et al. (2004) observed that
organic residues could be a catalyst for microbial activity and induce binding of soil
particles into macro-aggregates. Saturated hydraulic conductivity (Ks) is a quantitative
measure of a saturated ability of the soil to transmit water when subjected to a hydraulic
gradient. Xin et al. (2016) also noticed that saturated and unsaturated hydraulic
conductivities at one cm matric suction were two times higher in organic manure-

5
 treatment than in other treatments. They also reported that manure treated soil retained
more water as compared to control at tensions 200–900 cm water column. Fueki et al.
(2012) reported that infiltration rate was 6 to10 fold higher in soils under organic
farming than under conventional soils. Jenkins et al. (2011) reported significantly higher
infiltration rates in organically managed grassland soils (7.6 mm/h) than in
conventionally managed grassland soils (2.5 mm/h). Organically managed soil increased
soil water retention at 0–5 cm depth between matric suctions 10–619 cm and at 10–15
cm between matric suction values of 15500 cm, respectively (Crittenden et al. 2015).
Arriaga and Lowery (2003) reported significant increase in soil water retention from 0 to
7.6 cm with manure additions for the slight and moderate erosion phases, but not for the
severe phase.

2.2 Effect organic Farming on Chemical property of soil

Soil pH is influenced by different seasons, cropping systems and soil management

practices including application of synthetic agro-chemicals and manures. Sihi et al.
(2017) reported that the soil pH was 0.5 units lower in organic fields than in
conventional fields with the long-term incorporation of FYM, neem cake, and green
manuring in transplanted basmati rice in sandy loam. Mahmood et al. (2017) reported
that organic manure additions reduced the pH of soil irrespective of its nature.
Yaduvanshi (2003) also observed a reduction in soil pH with green manure or farmyard
manure application in alkaline soils. Sharma et al. (2014) reported that soil pH decreased
in plots receiving FYM along with the fertilizers than in only chemical fertilizer
plots .Nagar et al. (2016) reported lower pH and electrical conductivity in legume based
intercropping systems of pigeon pea-black gram and pigeon pea-green gram. Long-term
incorporation of FYM, neem cake and green manuring resulted in higher cation
exchange capacity (CEC), DTPA-extractable micronutrient (Mn, Fe, Zn, and Cu)
contents in soil under organic management (Sihi et al. 2017). Ayoola and Titilola (2006)
reported higher CEC, total nitrogen, available P, and exchangeable K in organic plots
than in inorganic plots in a cassava-based cropping system. Soil organic carbon (SOC) is
considered to be an important soil quality indicator, which influences physical, chemical,
and biological processes in the soil. Panwar et al. (2010) also concluded that application
of cattle dung manure, vermicompost, and poultry manure resulted in higher SOC and
ammonium-N in organic farming followed by integrated and chemical farming in deep
Vertosol soil. Shaikh and Gladhanded (2013) also reported increased soil organic carbon

6
 in organic farming over the inorganic farming. Banger et al. (2009) reported that the
application of organic or integrated fertilization resulted in increased build-up of SOC
than in control plots. Aher et al. (2015) reported that soil organic carbon was
significantly higher in the organic farming practices than in the chemical farming and
integrated farming practice plots. Maqueda et al. (2011) concluded that the use of plant
compost resulted in an increase in DTPAextractable Fe, Cu, Mn, and Zn contents
compared to inorganic fertilization.

2.3 Effect organic Farming on Biological property of soil

Soil biological health is an indicator of soil macro and microorganisms, which constitute
the living part of soil and important component of organic farming systems. Diversity of
beneficial rhizospheric bacteria and fungi were higher in organic management than in
conventional system in surface and sub-surface soil layers after 12 years of management
(Velmourougane 2016). Nagar et al. (2016) reported that application of organic manure
and pigeon pea stalks in soil resulted in higher fungal, bacterial, and actinomycetes
population in pigeon pea based intercropping systems. Soil respiration under organic
farming was 20% higher than in the control plots in turmeric (Dinesh et al. 2010).
Araujo, Santos, and Monteiro (2008) and Sudhakaran, Ramamoorthy, and Kumar (2013)
concluded that soil respiration and microbial population were higher in organic farming
than in conventional and sustainable farming. Dehydrogenases (DHA) are intracellular
enzymes that are involved in microbial oxido-reductase metabolism in soils and their
activity is considered an indicator of microbial oxidative activity, which is positively
related with soil respiration and organic matter decomposition. Jaggi et al. (2018)
reported that soil amended with green manure increased enzyme activities than soil with
inorganic fertilizers. The application of FYM, green manuring and neem cake had higher
DHA than recommended dose of agro-chemicals (Sihi et al. 2017). Simon and Czako
(2014) reported significantly higher dehydrogenase activity in organic treatment than in
control. Bhavani et al. (2017) reported that DHA was the highest in recommended dose
of NPK fertilizers with FYM followed by FYM alone at 10 t ha1 . Dinesh et al. (2010)
reported 29% higher DHA activity in organic management as compared to the chemical
management. Haidari, Mohammadi, and Sohrabs (2016) concluded that soil treated with
a mixture of compost and FYM had the maximum alkaline phosphatase activity as
compared to afro-chemicals treatment. Organic farming practices resulted in higher
enzyme activities for DHA and alkaline phosphatase activity than in integrated or

7
 chemical farming practices (Aher et al. 2015). Liu et al. (2010) reported that organic
manure application significantly increased DHA, alkaline phosphatases, b-glucosidases,
and urease activity as compared to control. Nima et al. (2020) reported that organic
farming with green manuring to basmati rice and farmyard manure to wheat in basmati
rice-wheat cropping system significantly increased dehydrogenase activity and basal soil
respiration by 55.6 and 50.3%, respectively than with chemical farming.

3. THE IMPORTANCE OF ORGANIC FARMING ON CROP YIELD

IMPROVEMENT

Soil fertility is fundamental in determining the productivity of all farming systems

Watson, et al. and thus inseparable from food security. Soil fertility is often defined as
the soil’s ability to supply nutrients to crops but it can be defined more widely as an
ecosystem concept Swift, et al. which integrates the diverse functions of soil that
promote plant growth, including nutrient supply [12]. This broad definition is fitting as
organic farming recognizes the complexity of relationships between different
components of any farming system and that sustainability depends on the functioning of
the whole integrated system [13]. A basic concept of organic farming is that “the health
of soil, plant, animal and man is one and indivisible” Balfour, et al. Organic farming
systems rely on the management of soil organic matter to enhance the chemical,
biological, and physical properties of soil, in order to optimize crop production and
health Thus, the supply of nutrients to crops, and subsequently to livestock and humans,
is the net result of a set of management decisions including rotation design, manure
management, etc., as well as soil management peruse. The central concept of soil fertility
in these systems is the use of legume-based multi-annual rotations together with the
careful use of on-farm manures Stockdale, et al.

The principle of health: Organic agriculture should sustain and enhance the health of
soil, plant, animal, human and planet as one and indivisible. The principle of ecology:
Organic agriculture should be based on living ecological systems and cycles, work with
them, emulate them and help sustain them. The principle of fairness: Organic agriculture
should build on relationships that ensure fairness with regard to the common
environment and life opportunities. The principle of care: Organic agriculture should be
managed in a precautionary and responsible manner to protect the health and well-being
of current and future generations and the environment [20].

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 4. CHALLENGE OF ORGANIC FARMING ADOPTION IN ETHIOPIA

4.1 Lower productivity

An organic farm cannot produce as much yield as a conventional or industrialized farm.

Organic agriculture generally have lower yields and need more land to produce the same
amount of food, which may have negative impacts on the environment and food security.
Moreover, lower yields of may translate into higher unit costs of production and lower
profits for farmers in the absence of price premiums.

4.2 Requires skill

An organic farmer requires greater understanding of his crop and needs to keep a close
watch on his crops as there are no quick fixes involved, like pesticides or chemical
fertilizers. Sometimes it can be hard to meet all the strenuous requirements and the
experience to carry out organic farming. Time consuming: Significant amounts of time
and energy are required to execute the detailed methods and techniques that are required
for a farm to be called an organic farm [21]. Failure to comply with any of these
requirements could result in loss of certification, which the farmer will not be able to
regain in up to three years. And it can be more time-consuming. Organic agriculture
increases soil fertility by way of compost, and organic fertilizers and mulch. Organic
fertilizers tend to be slow-release. As with control by botanicals, horticultural oils, and
insecticidal soaps, organic fertilizers may need several applications before the desired
results are brought about.

4.3 Labor-intensive

It can be more labor-intensive. For organic farming considers biological, cultural and
mechanical responses to production challenges. It focuses on plant and soil health
through proper aeration, drainage, fertility, structure and watering.

. Most of the farmers did not know the significance of organic agriculture due to lack of

awareness as a result farmers were not used for food production, so Provision of
awareness and support to farmers are very crucial in order to benefit them through use of
organic agriculture such as vermicomposting, Bio-fertilizer, compost and other
technologies of organic agriculture.

9
 • Also a focus on building strong relationships both within the farmers group and
linkages with local and wider stakeholders may enhance long-term sustainability of
organic agriculture.

• Increasing public awareness of the value of organic agriculture

• Implementing policy changes that ensure organic farming meets the rapidly growing
consumer demand

• Conducting research to arrive necessary technological advances.

• A new policy to support organic farmers and organic food industry is needed.

• Government attention and special consideration should be needed for better adopting
of organic agriculture as strategies.

• The government should increase research that is responsive to organic farmer’s needs,
integrate organic programs into every federally funded university, create farm safety net
and transition assistance programs that works for the growers.

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 5. SUMMARY AND CONCLUSION

Organic production system, one of the most discussed alternative farming systems,
influences the quantity and the quality of agricultural production in relation to soil
mechanisms operating concurrently within an ecosystem. It undoubtedly, improves soil
health due to application of organic manures and composts and adoption of legume based
diversified cropping systems but its lower productivity vis-a-vis conventional system
makes it a debatable issue. The productivity levels vary with the crops, cropping systems
and the agro-climatic locations. In terms of qualitative aspects, organically raised
produce has definitely an edge over the conventional produce in respect of defense
nutrient elements. Sans the productivity, quality and food security issues, organic
farming surpasses the chemical based conventional farming in terms of ecosystem
services.

Organic Agriculture is production management system which promotes and enhances

agro ecosystem health, including bio diversity, biological cycles and soil biological
activity and this accomplished by using on farm agronomic, biological and mechanical
methods in exclusion of all synthetic off-farm inputs .It works in together with nature
rather than against it. This involves using techniques to achieve good crop yields without
harming the natural environment or the people who live and work in it and helps small
scale farmers to achieve food from their domestic production without the use of chemical
fertilizers, pesticides and herbicides. In another way organic agriculture is kind of
agricultural that provide the consumers, with fresh, tasty and reliable food while
regarding natural life cycle systems. Therefore, to achieve food self-sufficiency the
policy should focus on small scale-organic agriculture in addition to promote commercial
agriculture. Specifically, the government should control land use for organic agriculture,
improve the efficiency of water management and other supports, stimulate awareness of
natural resource and environment conservation and encourage activities to maintain
community culture of helping one another. Organic agriculture is very important as
strategy for achieving food self-sufficiency through use of organic sources, however,
there are a gap in using organic agriculture .Therefore; to reduce these gaps the following
recommendation has been proposed.

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