1.1 Introduction
Soybean is often referred to be a marvel plant because it holds high protein (39-44%) and oil content (21%) (Hamayun et al., 2010). Soybean (Glycine max L.) is a member of Fabaceae family and mainly supplies protein and oil. Its oil considers the world's largest constituent of edible oils (Arif et al., 2010). Soybean is one of the most widely planted and used legumes in the world due to its valuable seed composition. Soybean is one of the most important source of oil and protein and is commonly used in both human and animal diets. For better production of soybean, it is compulsory to focus on the application of different essential nutrients in the form of fertilizers. One of the main causes in decline the soybean production is unbalanced fertilization of nutrients (N, P and K). Phosphorus is the main nutrient contributing to the stabilization of biological nitrogen in soybean and eliminates 28 kg of P/ha from the soil (Goswami, 2016).
As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Research questions, Limitations of the Study and Definition of technical terms.
1.2 Background of Study
Soybean is a member of the Fabaceae family, rich in nutrients. Soybean is not only seen as an oil plant but also used for various purposes. Among grain legumes, soybean is an economically important crop that is grown in diverse environments throughout the world. Its adaptation to tropical and subtropical regions is still involving extensive breeding work. To use land continuously for crop cultivation, incorporating organic and inorganic fertilizers to soil would provide multiple benefits for improving the chemical and physical status of the soil which results in improved crop yield (Ferguson et al., 2006). Both organic and inorganic fertilizers are sources of mineral elements, which plants require for effective growth and development (Ferguson et al., 2006).
Essential mineral elements are required in optimum amounts and are classified into micro and macro nutrients. Nitrogen, phosphorus, and potassium have great effects in plant growth and development. Their deficiencies or excesses result in marked effects on the growth and yield of crops. Nitrogen is a chlorophyll component, and it promotes vegetative growth and green colouration of foliage. Phosphorus plays a major role in photosynthesis, respiration, energy storage, cell division, and maturation.
The most important crop nutrients in agricultural systems are nitrogen (N), phosphorus (P), and potassium (K) (Chiezey, 2001). Most compound fertilizers will contain three elements essential for plant growth: NPK which stands for nitrogen (promotes leaf growth), phosphorus (root, flower, and fruit), and potassium (stem and root growth and protein analysis). Soybean nitrogen (N) requirements are met in a complex manner, as this crop is capable of utilizing both soil N (mostly in the form of nitrate) and atmospheric N (through symbiotic nitrogen fixation) (Kakaret al., 2002).
Phosphorus deficiency is probably one of the greatest constraints for agriculture. Phosphorous has been shown to be an essential element, and its application has been shown to be important for growth, development, and yield of soybean (Kakaret al., 2002).
Therefore, in Nigeria where the research was carried out, the activities that was conducted is to investigate the Effect of Phosphorus Level on the Grain Yield and Yield Components of Soybean.
1.3 Statement of Problems
Investigation revealed that the problem associated with utilization and processing of soybean is the presence of certain anti-nutritional factors which may inhibit the availability of the desired nutrients such as protein and minerals. Some of the prominent anti-nutritional factors in soybean include trypsin inhibitors, hemaglutinin, phytic acid, goitrogen, urease activity and flatulence causing factors (Osho and Dashiell, 1995).
1.4 Aim and Objectives of Study
The aim of the study is to investigate the Effect of Phosphorus Level on the Grain Yield and Yield Components of Soybean. In achieving this aim, the following specific objectives were laid out as follows:
- To evaluate the effect of phosphorus on quality and oil contents of soybean;
- To investigate the effect of phosphorous on growth and yield of soybean; and
- To examine the role of phosphorus in improving growth yield and quality of Soybean.
1.5 Research Questions
The study came up with research questions so as to be able to ascertain the above stated objectives. The specific research questions for the study are stated below as follows:
- What is the effect of phosphorus on quality and oil contents of soybean?
- What is the effect of phosphorous on growth and yield of soybean?
- What is the role of phosphorus in improving growth yield and quality of Soybean?
1.6 Significance of Study
This study will be of immense benefit to other researchers who intend to know more on this study and can also be used by non-researchers to build more on their research work. This study contributes to knowledge and could serve as a guide for other study.
1.7 Scope of Study
The scope of the research is focused on the Investigation of the Effect of Phosphorus Level on the Grain Yield and Yield Components of Soybean.
1.8 Limitations of the Study
During the course of this study, many things militated against its completion, some of which are:
- Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
- Research material: availability of research material is a major setback to the scope of the study.
- Frequent power failure: This made the researcher append more money on fuel to ensure sustainable power.
- Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet).
