Secondary research on the profile of mung beans were studied and the optimal pH level for mung beans to grow is pH 6.2 to 7.2 and the experiment was designed to investigates in to the effect of pH level of soil (5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5) on the growth rate of mung beans during a three week experiment, investigating to what extent pH level of soil could affect the growth on mung beans. Growth rate is assessed by measuring and calculating the percentage change for the following indicators: stem height, leaf length, number of leaves.
1 Introduction The research question is:
“What is the effect of pH level on the growth rate of mung beans?”
This investigation aims to investigate and analyze the effects of pH on the growth rate of mung beans with a 3 week experiment as 2 weeks is certainly enough time for the mung beans to complete (sprout people) . The purpose is to determine at which pH levels of solution will cause the most growth and at which pH levels slow down or stop the growth of the mung beans. I chose to use a pH range of 5.0 – 9.5 for this experiment as too high or too low pH levels would potentially prevent the plants from growing.
This investigation is composed of secondary researches, analysis of data and experimentation designed to collect data on pH level of soil and the growth rate of mung beans to explain the correlation between pH level and the growth of mung beans. This is substantial as it gives an important scope of the possible result of long term acid rain in Hong Kong because the pH level of acid rain may vary from a pH level of 5.6 to a low of 4.5 with the average value of 5.0 (Charles E. Ophardt). Therefore acid rain can be represented by a solution with a pH level of 5.0, simulating the effect of acid rain on the growth rate of plants.
2 Investigation Figure 1 shows the pH scale. For the any plants grow in a healthy condition, certain pH levels are critical to the growth of the plants. These different levels of pH are sure to affect the growth of the plants. For the majority of plants, it is best to have an acidic to neutral pH level (pH 6.0 to pH 7.0). Plants are incapable to grow without nutrients which are normally found in soil, if the plants are grown in an acidic soil for example >pH5, the natural nutrients in the acidic soil filtered out of the soil much more rapidly than from soils with the value between 5.0 and 7.5. (Leonard Perry, 2003) whereas between 5.0 and 6.5, natural nutrients are commonly accessible for the plants. Therefore in this investigation, pH range from 1.0 to 5.0 and 9.0 to 14.0 that will stop the plant from growing will not be included in this experiment.
Figure 1 shows the pH scale and examples of solution at each pH level. Figure 1 also shows that acid rain has a pH level of around 4.5 – 5.0. This theoretically suggests that acid rain could potentially filter out the nutrients in the soil hence decreasing or stopping the growth of the plants as they are unable absorb optimal amount of nutrients in order to grow. Therefore, hypothetically, pH 5.0 in this experiment will experience very little growth or it will be unable to sustain itself and die in a very short period of time.
2.1 pH level of solution experiment design
In this experiment, pH level of solution is considered because it is the most important factor required to determine the growth of the mung beans and it was chosen because I want to determine what pH solution is best suited for the growth rate of mung beans as well as to simulate the acid rain in Hong Kong to examine the effect acidic rainfall on the soil and how it affect the growth of mung beans in farmlands. Therefore other independent variables such as temperature and light intensity were excluded from this experiment. In order to record sufficient data on the overall growth rate of the mung beans in this experiment, three parameter including stem height, length of leaves, number of leaves are chosen as dependent variables to identify the possible effects of different pH on the growth the mung beans.
Stem Height: Determine the height of the stem by measuring the height from the border of the pot to the top of the mung bean stem
Length of leaves: Determine the length of leaves by measuring the distance from one end to another end
Number of leaves: Determine the number of leaves by counting the amount of leaves in the mung beans.
Human Skeleton and Muscles: Anatomy and Physiology
UNIT TITLE: ANATOMY