Final: The Effect of Different Types of Water on the Growth of Bean Plants(Olivia 2)

This topic submitted by Kelly Conway, Andrea Lucarelli, Joanna O'Connor, Jenny Rodgers ( ) on 12/11/98 .

Final Lab Report For The Extent That Different Types Of
Water Affect The Growth Rate Of Bean Plants(Olivia 2:00)

This research topic is submitted by Jenny, Andrea, Kelly, Joanna on 12/11/98

1. Question:

How is the growth rate of bean plants affected by
different types of water?

2. Introduction:

We are going to be exploring the affect that different type of water have on the growth rate of bean plants. We will be experimenting with two different types of bean plants and testing
three different types of water.

PH is basically the negative log of hydrogen ion activity used to measure the acidity or basicity. The pH level ranges on a scale from one to fourteen, one being most acidic, fourteen being most basic, and seven being neutral (Soil pH and Fertilizers). A pH level of 6.5 or slightly acidic is ideal to most plants because nutrients are most readily available between a range of six to seven (Soil pH and Fertilizers). If the pH falls below four or above nine, a living organism dies(Water Quality Tests). The pH of a soil is its measure of relative acidity or alkalinity; pH is an acronym for potential hydrogen. The availability of nutrients is directly affected by soil pH. Past studies have shown that pH is a strong indicator of soils that are chemical properties. The hypothesis for our experiment is that all the plant trials will grow, but the filtered water plants will grow most rapidly, as filtered water has fewer contaminants and more nutrients. By completing this experiment, we plan to determine which type of water is ideal for growing the healthiest indoor
plant. The results of this experiment may be relevant in greenhouse and indoor planting.

In our experiment we will also be considering the effects that the pH has on the soil. Soil that is too acidic or too basic does not promote healthy plant growth, due to the fact that, in both cases, the plants are deprived of their nutrients, which is harmful to helpful
bacteria. If the soil’s pH is too high or too low, some nutrients become insoluble, limiting the availability of these nutrients to the plant root system. Our goal is not only to study the pH levels of
soil, but to compare them to kidney and lima bean plant growth. We believe that through regular watering of the bean plants, the soil will be altered by the different pH levels of the water. We also
believe that the pH level of the soil is a significant factor in determining how well the bean plants will grow. Again, we hypothesize that the soil that is watered with the filtered water will be the
closest to neutral, therefore these plants will grow the best.

3. Relevance of Our Research Question:

In the past, similar research has been conducted with different types of waters on plants. One known experiment performed, was testing the wilt of flowers when they were placed in distilled, hard, soft, and lake water. This is somewhat similar to our experiment as we are using pond water, filtered water, and tap water; however, instead of testing the wilt of flowers, we are testing the durability and growth rate of the plants.

Our research may relate to a question of what kind of water may produce the best results for indoor vegetation or greenhouse work.

4. Research Design and Method

The materials for our experiment include:
1. 36 Red Kidney beans
2. 36 Lima beans
3. 72 16 oz. plastic cups
4. 40.5 pounds of Green Charm potting soil
5. Measuring cups
6. 165 ounces of Filtered water
7. 165 ounces of Pond water
8. 165 ounces of Tap water
9. Electronic pH tester
10. Metric ruler

The procedure entails the following:

First, fill seventy-two 16 ounce cups with three ounces of potting soil. In thirty-six of the plastic cups, place one red kidney bean in each of the cups; in the other thirty-six cups, place onelima bean in each cup. Then fill each cup with an additional six ounces of potting soil.

Next, place the individual cups in the greenhouse, giving each plant ample space to grow in between cups. To ensure that each plant receives equal amounts of sunlight, rotate the plants every week, for the duration of the experiment, which will last five weeks.

The types of water that will be used include filtered water, tap water, and water from the Western Duck Pond. The control group will be the tap water, as it is the purest water, and most likely the type of water that most people water their house plants with. Prior to watering the plants,the pH levels of the three different types of water was tested with an electronic pH-level tester. The pH levels of the water was tested to be 7.1 for the Brita, 7.0 for the tap, and 6.8 for the pond water. Also, the turbidity of the waters and any additional nutrients or contaminants will be examined and

Each of the two different types of bean seeds will be watered by each of the three different types of water. Of the two different seed groups (thirty-six red kidney beans or thirty-six lima beans), twelve will be watered regularly with filtered water, twelve with pond water, and twelve with tap water. The plants will be watered approximately the same time every four days with two ounces of each specified water. Once plant growth is visible, the growth rate of each individual plant will be measured with a metric ruler and recorded. This will be done each day after watering. Also, any discoloration of leaves, or any other noticeable differences between the plants will be
noted. After the five week growth period, the roots of each individual plant will be examined to determine any differences thickness, stability color, etc. This experiment should be statistically sound, as any extra outside variables and experimental errors have been accounted for (such as a controlled greenhouse environment and rotation of the plants to ensure equal sunlight).

Time Line:
Oct. 9: Begin experiment
Oct. 19: Experiment went bad
Oct. 20: Re-do experiment
Nov. 17: Finish watering
Nov. 18: Begin analyzing roots and plant growth
Nov.30: Class discovery lab/ experiment on soil
Nov. 30: End experiment

5. Data / Results

Average Weekly Grwoth of Plants (cm)
Nov.4 Nov.6 Nov.11 Nov.13 Nov.16 Nov.18 Nov.23 Nov.30
Brita Water
Kidney 3.8 15.2 19.4 20.4 22.0 23.4 25.8 20.6
Lima 2.5 4.2 8.8 9.5 9.8 10.0 11.0 10.5

Tap Water
Kidney 6.2 8.5 14.2 15.8 17.5 19.1 20.7 18.7
Lima 6.1 7.6 11.1 11.5 12.2 6.3 10.2 10.2

Pond Water
Kidney 8.3 10.0 15.3 13.2 14.1 12.8 14.1 12.6
Lima 5.8 5.9 13.8 14.6 15.2 15.5 15.2 12.8

6. Analysis

After concluding the four week watering period, we took a final measurement of all of the plant growths and compared them to the prior data. We discovered that there was no correlation between the types of water and the plant growth. This could have been attributed to high plant fatality and a very close range of pH levels in the different types of water.

The first time that we planted the seeds, there was no plant growth due to the lack of a drainage system. After consulting with our instructor, she advised us to soak new seeds overnight before replanting the beans and to puncture the cup’s bottom in order to allow the excess water to drain adequately.

When we began our experiment the second time, we planted two bean seeds in each cup to insure a high rate of growth. All the seeds were treated in the same manner. They were soaked overnight in the same container, and they were planted in the same position in the cups which was just below the soil.

After the first two weeks we noticed that many of the plants were not sprouting at all. When the experiment was completed, 75 percent of the plants had not grown at all. For example, the plants that were watered with the pond water had a seventeen out of twenty-four fatality rate for bean plants. For the plants that were watered with tap water, there was a fifteen out of twenty-four fatality rate, and for the plants that were watered with filtered water, there was a eighteen out of twenty-four fatality rate. This significantly high fatality rate could be attributed to the planting process, the method of watering, and the holes in the bottom of the cups. When planting the seeds in the soil it is possible that the seeds may have been damaged. This could have happened through handling them after they had been soaked and were in a very fragile state. Watering
methods could have affected the plants because the plants may have needed more water than was given them. Another factor could have been that the holes in the bottom of the cup could have been too small. This would not have allowed the water to drain properly causing the seeds to rot. One other reason for the high fatality rate could have been the turbidity of the water.

These things occurred at the beginning of our experiment and were not caused by our own lack of attention to details. When we analyzed the plants that did grow, we found that overall the kidney beans had a higher average growth rate as well as a higher average height.
Brita: Out of the four kidney bean plants that grew the
average height was found to be 25.8 centimeters.
The two lima bean plants that grew averaged a height
of 11.0 centimeters.
Tap: Out of the six kidney bean plants that grew the
average height was 20.7 centimeters.
The three lima bean plants that grew averaged a height of 12.2 centimeters.
Pond: Out of the five kidney bean plants that grew the
average height was found to be 15.3 centimeters.
The two lima bean plants that grew averaged a height
of 15.5 centimeters.

7. Conclusion:

We conclude that the three different types of water; pond, tap, and Brita, had no real effect on the growth rate, survival, or height on the bean plants. Although the turbidity of the waters was significantly different, the pH levels of the water were so close that they had no noticeable effect on the plants. When comparing the tallest plants, there is no true consistency in the waters’
relationship to the plants’ height.

Brita was the “best” water for the kidney bean plants with an average height of 25.5 centimeters per growing plant, but was the least effective for the lima beans which had the lowest
overall average height of 11.0.

The purpose of this experiment was to determine whether or not the different pH levels of water would affect the rate of growth in indoor plants. The hypothesis stated was that the plants grown in the Brita, filtered water would grow the best and be the healthiest. Through this experiment, it was discovered that the stated hypothesis was wrong. This experiment proved that the pH and the turbidity of water will not affect the growth of plants. Since the ranges of the pH
levels were so close, this does not necessarily imply that, had the pH levels been further apart, the results would have been the same.

8. Works Cited

Evans, G. Clifford. The Quantitative Analysis of Plant Growth. Los Angeles: University of California Press, 1972.

“Factors Affecting Availability of Phosphorus.” 28 December 1996.

Hunt, Roderick. Basic Growth Analysis. Boston: Unwin Hyman, 1990.

Mayer, A. M. and A.Poljakoff-Mayber. The Germination of Seeds. New York: Pergamon Press, 1975.

“Soil pH and Fertilizers” 12 August 1998.

“The Water Quality Test.” 12 February 1997.

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