Project – The Effect of Organic Fertiliser Application on the Growth and Yield of Maize: A Case Study of Selected Farms in Oyo State.

CHAPTER ONE

INTRODUCTION

Research Topic: The Effect of Organic Fertiliser Application on the Growth and Yield of Maize: A Case Study of Selected Farms in Oyo State

1.1 Background to the Study

Agriculture remains one of the most important sectors of economic development in Nigeria, contributing significantly to food security, employment generation, poverty reduction and the supply of raw materials for agro-based industries. Crop production, in particular, plays an essential role in sustaining rural livelihoods and meeting the food requirements of the growing population. Among the major cereal crops cultivated in Nigeria, maize (Zea mays L.) occupies an important position because of its wide consumption as food, livestock feed and industrial raw material. Its production provides income and employment opportunities for millions of farming households, particularly smallholder farmers who depend on crop cultivation for their livelihoods. However, the productivity of maize is influenced by several factors, including soil fertility, rainfall distribution, availability of improved seeds, pest and disease management, farming practices and the application of appropriate fertilisers. Soil fertility is particularly important because maize requires adequate quantities of essential nutrients for proper vegetative development, flowering, grain formation and maturity. According to the International Institute of Tropical Agriculture (IITA, 2009), maize is an important staple crop in sub-Saharan Africa, and improving its productivity requires appropriate agronomic practices and effective soil fertility management. Similarly, Vanlauwe et al. (2010) emphasised that integrated soil fertility management is essential for improving crop productivity and maintaining the productive capacity of agricultural soils in Africa. These considerations establish the importance of proper fertiliser application in achieving improved maize growth and yield.

Soil fertility deterioration has become a major concern in agricultural production, particularly in developing countries where continuous cultivation, soil erosion, nutrient depletion and inadequate soil management practices affect the productive capacity of farmlands. The removal of nutrients through repeated harvesting without adequate replenishment gradually reduces the availability of essential elements required for crop development. Maize production is particularly sensitive to nutrient deficiencies because the crop requires sufficient nitrogen, phosphorus and potassium, alongside other essential nutrients, to support healthy growth and grain formation. When these nutrients are inadequate, maize plants may experience stunted growth, poor leaf development, weak stems, delayed maturity and reduced grain yield. Organic fertilisers have therefore attracted considerable attention as a means of improving soil fertility through the addition of organic matter and plant nutrients. They are derived from natural materials such as animal manure, compost, crop residues, household organic waste and other decomposed biological materials. Vanlauwe et al. (2010) explained that sustainable soil fertility management in African farming systems requires practices that replenish soil nutrients and improve the physical, chemical and biological properties of the soil. Similarly, Ayoola and Makinde (2009), in their experiments conducted in Ibadan, Nigeria, demonstrated that nitrogen-enriched organic fertilisers could improve maize growth and produce favourable yield outcomes. These findings indicate that organic fertiliser application is an important agricultural practice for addressing soil fertility problems and supporting sustainable maize production.

Organic fertilisers are materials obtained from plant and animal sources that are applied to agricultural soils to improve nutrient availability and enhance soil productivity. Common examples include poultry manure, cow dung, pig manure, goat droppings, compost manure, farmyard manure and decomposed plant residues. Unlike many inorganic fertilisers that supply nutrients in readily available mineral forms, organic fertilisers release nutrients gradually as microorganisms decompose the organic materials in the soil. This process contributes to soil organic matter accumulation, improves soil structure, enhances water retention and supports beneficial soil microbial activities. The effectiveness of organic fertilisers, however, depends on their nutrient composition, level of decomposition, application rate, method of application, soil characteristics and environmental conditions. Ojo, Adetunji, Okeleye and Adejuyigbe (2015), in their research on soil fertility, phosphorus fractions and maize yield, established that poultry manure application improved soil pH and organic carbon, while the combination of poultry manure and phosphorus fertiliser produced favourable results for several soil and crop parameters. Similarly, Ayoola and Adebayo (2017), in their study of different organic fertiliser sources in southwestern Nigeria, found that poultry manure, cow dung and Oyo organic fertiliser significantly influenced maize growth and yield components. These findings demonstrate that organic fertilisers can serve as important sources of plant nutrients while contributing to the improvement of soil conditions required for successful maize cultivation.

The application of organic fertilisers has several potential benefits for maize growth, particularly during the vegetative stage when plants require sufficient nutrients for the development of leaves, stems and roots. Nitrogen is essential for chlorophyll formation and vegetative growth, phosphorus supports root development and energy transfer, while potassium contributes to water regulation, enzyme activation and general plant health. Organic fertilisers containing these nutrients can improve the availability of essential elements and create favourable conditions for maize development. Their contribution to soil structure and moisture retention may also support crop establishment, particularly in soils with low organic matter content. Ayoola and Makinde (2009), in their study of maize growth, yield and soil nutrient changes under nitrogen-enriched organic fertilisers in Ibadan, reported that organic fertiliser treatments improved maize growth, with some treatments producing plant heights comparable to those obtained under inorganic fertiliser application. In addition, Mbabah, Anyanwu, Idiong, Ekette and Johnson (2024), in their investigation of different manure types in southern Nigeria, found that poultry droppings significantly improved maize growth and yield attributes, with the 20 tonnes per hectare treatment recording the highest mean values among the treatments examined. These findings suggest that the appropriate application of organic fertilisers can enhance important growth characteristics of maize, including plant height, stem development, leaf production and general vegetative performance.

Beyond vegetative development, organic fertiliser application is also important in determining the yield and overall productivity of maize. Yield is one of the major indicators used to assess the effectiveness of agricultural production practices and is commonly measured through parameters such as number of cobs per plant, cob length, cob diameter, number of grains per cob, grain weight and total grain yield per hectare. Adequate nutrient availability during flowering, pollination, cob formation and grain filling is essential for achieving good maize yield. Organic fertilisers can contribute to these processes by supplying nutrients and improving the soil conditions necessary for crop development. Ayoola and Adebayo (2017) conducted field experiments in two agroecological locations in southwestern Nigeria and found that poultry manure combined with urea produced the highest maize grain yields of 4.91 tonnes per hectare at Ilora and 5.04 tonnes per hectare at Ibadan, while the unfertilised control recorded lower yields of 2.67 and 2.98 tonnes per hectare, respectively. Similarly, Ojo et al. (2015) demonstrated that the combined application of poultry manure and single superphosphate produced the highest grain yield among the treatment combinations investigated. These findings show that the use of organic fertilisers can contribute to improved maize yield, although the outcome depends on the nutrient requirements of the crop, the characteristics of the soil and the management practices adopted by farmers.

The importance of organic fertiliser application is particularly relevant to agricultural production in Oyo State, which has a long history of crop cultivation and is characterised by farming activities involving maize, cassava, yam, vegetables and other food crops. Many farmers in the state depend on cultivated farmland for household income and food production, making soil fertility management an important consideration for sustainable agricultural development. The availability of organic materials such as poultry droppings, cow dung, crop residues and compost provides opportunities for farmers to improve soil fertility using locally accessible resources. However, the effectiveness of these materials may vary depending on their nutrient composition, availability, transportation, preparation and method of application. Adeniran, Fato, Abegunrin and Oyewole (2017), in their study of farmers’ perceptions of organic fertiliser use in maize production in Ido Local Government Area of Oyo State, found that poultry manure was the most commonly used organic fertiliser among the respondents, while the bulkiness of organic fertiliser was identified as a major constraint affecting its utilisation. Furthermore, Sekumade (2017), in a study of the economic effects of organic and inorganic fertilisers on maize yield in Oyo State, established that farmers’ decisions to use organic fertilisers were influenced by factors such as educational level, access to loans, extension services and farm size. These studies demonstrate the relevance of organic fertiliser to maize farming in Oyo State and the need to understand the factors influencing its application and effectiveness.

Despite the recognised benefits of organic fertilisers, their application does not always produce uniform results across different farms and production environments. The effectiveness of organic fertiliser depends on several factors, including the type of manure used, nutrient concentration, quantity applied, time of application, soil conditions, maize variety and prevailing climatic conditions. Inappropriate application rates may result in inadequate nutrient supply or excessive nutrient accumulation, while poorly decomposed manure may affect crop establishment and nutrient availability. Farmers may also experience difficulties relating to the collection, transportation, storage and application of bulky organic materials. Bello (2024), in a field investigation conducted during the 2022 and 2023 cropping seasons, found that organic manure application improved soil nutrient status and maize yield, with incorporated compost and poultry manure performing differently from surface-applied treatments. Similarly, Ayoola and Adebayo (2017) established that maize response varied according to the organic fertiliser source and maize variety used in their experiments. These findings indicate that the success of organic fertiliser application depends not only on its availability but also on appropriate selection, application rate and management practices. Consequently, there is a need to examine how organic fertiliser application affects the growth and yield of maize in selected farms in Oyo State, taking into consideration the types of organic fertilisers used, their application methods and their influence on maize growth and yield characteristics.

1.2 Statement of the Problem

Maize production in Nigeria continues to face challenges associated with declining soil fertility, inadequate nutrient management and the increasing cost of agricultural inputs. Many farmers cultivate their farmland continuously without adequately replenishing the nutrients removed through harvesting, resulting in gradual deterioration of soil productivity. This situation affects the growth and development of maize plants, particularly where essential nutrients such as nitrogen, phosphorus and potassium are insufficient. Although fertilisers are important for improving soil fertility and increasing crop yield, many smallholder farmers experience difficulties in obtaining sufficient quantities of inorganic fertilisers because of their high costs and limited availability during planting seasons. Consequently, some farmers depend on traditional soil management practices that may not provide adequate nutrients for optimum maize production. Vanlauwe et al. (2010) identified soil nutrient depletion as an important challenge to sustainable agricultural production in sub-Saharan Africa and emphasised the importance of integrated soil fertility management. Similarly, Ayoola and Makinde (2009) demonstrated that the application of nutrient-enriched organic fertilisers could improve maize growth and soil nutrient conditions. The persistence of soil fertility problems therefore raises concerns about the effectiveness of existing fertiliser management practices and the need to explore organic fertiliser application as an alternative for improving maize production.

Another major problem concerns the limited and inconsistent utilisation of organic fertilisers among maize farmers, despite their potential benefits to soil fertility and crop development. Organic fertilisers such as poultry manure, cow dung, compost and other animal wastes are locally available in many farming communities, but their application is sometimes limited by inadequate knowledge of appropriate application rates, preparation methods and timing. Some farmers may apply insufficient quantities of organic fertilisers, while others may use poorly decomposed materials or inappropriate application methods that reduce their effectiveness. In addition, the bulky nature of organic materials makes transportation, storage and field application difficult, particularly for farmers cultivating relatively large areas of farmland. Adeniran et al. (2017), in their study conducted in Ido Local Government Area of Oyo State, identified the bulkiness of organic fertiliser as a major constraint affecting its utilisation among farmers. They also reported that poultry manure was the most commonly used organic fertiliser among the respondents. These challenges suggest that the availability of organic fertilisers does not necessarily guarantee their effective utilisation and that farmers require appropriate information on their preparation, handling and application.

Furthermore, although previous studies have established that organic fertiliser can improve maize growth and yield, the extent of its effectiveness may differ according to the type of organic material, application rate, soil conditions and management practices adopted. For instance, poultry manure, cow dung and compost may contain different nutrient concentrations and release nutrients at different rates. These variations may influence important maize growth characteristics such as plant height, number of leaves, stem girth and leaf area, as well as yield components such as cob length, cob weight, number of grains per cob and total grain yield. Ayoola and Adebayo (2017) found that different organic fertiliser sources produced varying effects on maize growth and yield in southwestern Nigeria, with poultry manure combined with urea recording the highest grain yield in their experiments. Similarly, Ojo et al. (2015) established that the combination of poultry manure and phosphorus fertiliser influenced soil fertility and maize grain yield. However, these findings do not imply that all organic fertilisers or application methods will produce the same results under different farm conditions. There is therefore a need to examine the specific effects of organic fertiliser application on maize growth and yield in selected farms in Oyo State.

In Oyo State, although farmers have access to different sources of organic fertilisers and previous research has examined their utilisation and economic implications, there remains a need for further investigation into their direct effects on the growth and yield performance of maize under selected farm conditions. Existing studies, including those of Adeniran et al. (2017) and Sekumade (2017), have provided useful information on farmers’ perceptions, adoption and economic considerations associated with organic fertiliser use in the state. However, understanding farmers’ perceptions and economic decisions alone does not sufficiently establish the actual agronomic response of maize to different organic fertiliser applications. Furthermore, variations in fertiliser types, application rates, methods of application and soil characteristics may influence the effectiveness of organic fertilisers across different farms. The problem this study seeks to address, therefore, is the need to establish how organic fertiliser application affects the growth and yield of maize in selected farms in Oyo State, identify the organic fertiliser practices associated with improved crop performance and determine appropriate measures for enhancing the effective utilisation of organic fertilisers in maize production.

1.3 Objectives of the Study

The main objective of this study is to examine the effect of organic fertiliser application on the growth and yield of maize in selected farms in Oyo State.

The specific objectives are to:

1. Identify the different types and sources of organic fertilisers used in maize production in selected farms in Oyo State.

2. Examine the effect of organic fertiliser application on the growth characteristics of maize, particularly plant height, number of leaves, stem girth and leaf area.

3. Determine the effect of organic fertiliser application on the yield components and overall yield of maize in the selected farms.

4. Examine the challenges associated with the application and effective utilisation of organic fertilisers in maize production and suggest measures for improving their effectiveness.

1.4 Research Questions

The following research questions are formulated to guide the study:

1. What are the different types and sources of organic fertilisers used in maize production in selected farms in Oyo State?

2. What effect does organic fertiliser application have on the growth characteristics of maize?

3. How does organic fertiliser application influence the yield components and overall yield of maize in the selected farms?

4. What are the challenges associated with the application and effective utilisation of organic fertilisers in maize production, and what measures can improve their effectiveness?

1.5 Research Hypothesis

The following null hypothesis is formulated for the study:

H₀: Organic fertiliser application has no significant effect on the growth and yield of maize in selected farms in Oyo State.

1.6 Significance of the Study

This study is significant because it will provide useful information on the effects of organic fertiliser application on maize growth and yield. The findings will be beneficial to the following groups:

Maize Farmers: The study will help maize farmers understand the importance of organic fertiliser application in improving soil fertility and crop productivity. It will provide information on different organic fertiliser sources, appropriate application practices and their potential effects on maize growth and yield. This may assist farmers in making informed decisions about the use of locally available organic materials to improve their farming activities.

Agricultural Extension Officers: The study will provide useful information to agricultural extension officers on the effectiveness of different organic fertilisers in maize production. The findings may assist them in educating farmers on appropriate fertiliser selection, preparation, application rates and methods. It will also help extension officers promote sustainable soil fertility management practices among farming communities.

Government and Agricultural Policymakers: The findings will provide useful information to the Oyo State Government, agricultural development agencies and relevant policymakers on the importance of promoting organic fertiliser utilisation. The study may assist in developing agricultural policies and programmes that encourage the production, processing and distribution of organic fertilisers to improve crop productivity and sustainable agricultural development.

Agricultural Researchers and Institutions: The study will contribute to existing knowledge on organic fertiliser application and maize productivity. Agricultural research institutions may use the findings as a basis for further investigations into soil fertility management, organic fertiliser formulations and sustainable crop production practices.

Students and Academic Researchers: The study will serve as reference material for students, researchers and scholars interested in agronomy, crop science, soil fertility management, organic agriculture and agricultural productivity. It will also provide a foundation for further studies on the relationship between organic fertiliser application and crop performance.

Society and the Environment: The study will promote awareness of the environmental benefits of recycling organic materials for agricultural purposes. Effective utilisation of animal manure, compost and agricultural residues can reduce organic waste disposal problems, improve soil quality and encourage environmentally sustainable farming practices.

1.7 Scope of the Study

This study focuses on the effect of organic fertiliser application on the growth and yield of maize, using selected farms in Oyo State as a case study.

Geographically, the study will be restricted to selected farms in Oyo State, Nigeria. The specific farms will be determined based on the researcher’s selected study locations and accessibility to the farms.

In terms of content, the study will examine the different types and sources of organic fertilisers used in maize production, their effects on maize growth characteristics, their influence on yield components and overall maize yield, and the challenges associated with their application and utilisation.

The study will consider organic fertilisers such as poultry manure, cow dung, pig manure, goat droppings and compost manure. Growth characteristics will include plant height, number of leaves, stem girth and leaf area, while yield parameters will include number of cobs, cob length, cob weight, number of grains per cob and grain yield.

The study will also examine factors affecting the effective utilisation of organic fertilisers, including availability, transportation, preparation, application rates, timing and farmers’ knowledge of appropriate application practices.

1.8 Definition of Key Terms

Organic Fertiliser: Organic fertiliser refers to natural materials derived from plant and animal sources that are applied to agricultural soil to supply nutrients, improve soil structure and enhance soil fertility.

Organic Fertiliser Application: This refers to the process of introducing organic materials such as poultry manure, cow dung and compost into agricultural soil to improve nutrient availability and support crop growth.

Maize: Maize (Zea mays L.) is a cereal crop cultivated for its edible grains, which are used for human consumption, livestock feed and industrial purposes.

Growth: Growth refers to the progressive development of maize plants from germination to maturity, measured through characteristics such as plant height, number of leaves, stem girth and leaf area.

Yield: Yield refers to the quantity of maize harvested from a given area of farmland, commonly measured in terms of cob production, grain weight and total grain output per hectare.

Poultry Manure: Poultry manure refers to the organic waste produced by chickens and other domestic birds, which is used as a source of plant nutrients and soil organic matter.

Cow Dung: Cow dung refers to the faecal waste produced by cattle, which can be decomposed and applied to agricultural soil as an organic fertiliser.

Compost Manure: Compost manure refers to decomposed organic materials obtained from plant residues, animal waste and other biodegradable materials through a controlled decomposition process.

Soil Fertility: Soil fertility refers to the ability of soil to supply essential nutrients in adequate quantities and suitable proportions to support healthy plant growth and development.

Maize Productivity: Maize productivity refers to the level of maize output obtained from the land, labour, fertilisers and other agricultural resources used during production.

Project – The Effect of Organic Fertiliser Application on the Growth and Yield of Maize: A Case Study of Selected Farms in Oyo State.