Essay: How Does The pH Of Water Affect Plant Growth?

I. Introduction
A. Background Information and Research
There are many variables that affect how plants grow. Many of them are very crucial to the plant. First is the nutrients plants need to survive. Plants absorb sunlight they need for photosynthesis with chlorophyll. This sunlight becomes sunlight through cellular activities. Over a dozen nutrients are in soil that plants must absorb to grow strong. Flowering plants are the group of plants that have the most number of species. Sunlight is essential for all flowering plants, and they do best when the sun is shining. Many flowers need just the right amount of water, because to little could dry them up and kill them, and too much can flood the soil and kill the plants. For flowering plants to grow well, they need a balanced source of twenty minerals, elements, or nutrients. A plants ability to absorb nutrients can be affected by pH, and since plants feed on nutrients, they may lose health, stop growing, and then finally die because of not having the proper nutrients. The six essential nutrients are carbon, hydrogen, oxygen, nitrogen, phosphorous, and potassium. The first three are found in water and air. For flowering plants, slight nutrient deficiency. There are many ways to change the pH of water. Some easy ways are to add certain amounts of either acidic or basic things like lemon extract or baking soda.
B. Purpose/ Objective
To learn what the optimum pH of water is for flowering plants.
C. Hypothesis
If you use water that is at a pH of 7 to grow plants, then the plants will grow better than if they were grown using water of a different pH because water is naturally at a pH of 7.
D. Parts of The Experiment
1.dependant variable- Height of the plant
2. independent variable- pH of water used
3. control- plants that were given water of neutral pH
4. experimental group- Flowers
5. factors held constant- flowers, soil,pot size, amount of waater given daily
II. Materials
1. Water
2. Soil
3. Pots
4. Plants
5. pH strips
6. lemon extract
7. baking soda
III. Procedure
1. Plant 3 plants per pot, 3 for each water pH
2. Mix water with lemon extract in one tub to get a pH of 6.5 and one tub at a pH of 6.0.
3. Keep water in one tub at a neutral pH.
4. Mix baking soda with water in one tube to get a pH of 7.5 and a tub at a pH of 8.0.
5. Water each set of plants daily with the specified water.
IV. Observations and Data
A. Observations
Week 1 Observation- All plants growing at same height.
Week 2 Observation- All plants growing at same height.
Week 3 Observation- plants growing faster if grown with acidic water and slower if watered with basic water.
Week 4 Observation- plants growing even faster if grown with acidic water and even slower if watered with basic water. Large gap in height of plants.
B. Data
pH/Week Week 1 Week 2 Week 3 Week 4
pH 6 3 4 5 6
pH 6.5 3 4 4.75 5.5
pH 7 3 4 4.5 5
pH 7.5 3 4 4.5 4.75
pH 8 3 4 4.5 4.75
V. Calculations
A. Manipulated data (mean, slope/rate, standard deviation, % change, etc..)
Mean overall growth- 5.2 in
B. Statistical Analysis
Based on the mean overall growth of 5.2 in, we can see how much of a difference the acidic water made because it grew 6 in instead of the mean of 5.2 in.
VI. Analysis-
In my experiment I observed that as the pH of the water goes down, the rate of growth for the plant goes up. In my experiment lower pH water made plants grow much faster than high pH, at the end the one with a water pH of 6 grew to 6 inches and the plant watered at a pH of 8 only grew to 4.75 in. This is because flowering plants grow at a much higher rate when they absorb certain nutrients, and these nutrients are easiest to absorb when the pH is lower.
VII. Conclusion
In my experiment I observed that as the pH of the water goes down, the rate of growth for the plant goes up. My Hypothesis stated that if you use water that is at a pH of 7 to grow plants, then the plants will grow better than if they were grown using water of a different pH because water is naturally at a pH of 7. My hypothesis was incorrect but my purpose was achieved because I found out what pH flowers grow best at.
VIII. Sources of Error and Inaccuracies
Some sources of error and inaccuracies for this experiment are that the different flowers might have different parents which means that they may have different genes that predetermines how large and well the flower may grow.
IX. Application
This experiment applies to real life because by knowing this we can learn how to make flowering plants grow best, and this helps because you can learn how to grow your flowers for your garden better. We can use these results by using the optimum pH level to grow your plants better. It is important because if you use water of the wrong pH then your plants may not grow how you want them to.
X. Improvement
I could have improved my experimental design by using more plants and continuing the experiment for more weeks. As a continuation experiment I can test how soil pH affects plant growth to see whether water or soil pH matters most.
XI. Bibliography
Works Cited
“3.6”Absorption of Water and Nutrients by Roots.” 3.6”Absorption of Water and Nutrients by Roots. N.p., n.d. Web. 07 Jan. 2015. <http://plantsinaction.science.uq.edu.au/edition1/?q=content%2F3-6-absorption-water-and-nutrients-roots>.
“How Plants Get Water and Nutrients.” – For Dummies. N.p., n.d. Web. 07 Jan. 2015. <http://www.dummies.com/how-to/content/how-plants-get-water-and-nutrients.html>.
“Plant Nutrients.” Plant Nutrients. N.p., n.d. Web. 07 Jan. 2015. <http://www.ncagr.gov/cyber/kidswrld/plant/nutrient.htm>.
Roots, and Transform It into Organic Matter How Plants Absorb Their Food (n.d.): n. pag. Web.
“What Is a Flowering Plant? – Encyclopedia of Life.” Encyclopedia of Life. N.p., n.d. Web. 07 Jan. 2015. <http://eol.org/info/450>.