Do Sunflowers have a faster grow faster when watered with clean drinking water from the tap or with rain water collected outside?
If both plants receive the same amount of water each day, then the plants receiving rain water would have a faster growth rate. This is rain water has more nutrients in it then regular drinking water. These nutrients would make the sunflowers grow at a faster rate than the sunflowers with regular water.
Independent: the type of water, either clean drinking water from the tap. Dependent: the growth of the sunflower.
Control: Each plant will receive the same amount of water as any other. Also the plant will receive the same amount of sunlight as each other, lastly the plants will be measured and water at the same time every day.
Control of Variables
The way that the variables will be controlled are the plants will receive the same amount of water (¼ cup daily). This is to insure that they receive a proper amount for the plant to survive. The amount of light that the plants will obtain will be from the sun. The plants are to be placed in the same window to receive the same amount of lights (preferably a bay window). The plants will be measured the same time daily and also watered the same time daily so that there is no confusion that the plants could have had more growth time one day. Also, the plants will be measured with the same ruler every time they are measured to ensure the measurements are equal.
The materials needed for this biology lab are:
* 10 sunflower seeds per type of water (total of 20)
* 20 separate planters
* A ruler (for measurement)
* Two ¼ cup for watering the plants
* Source of rain water
* Source of clan drinking water
* Light source, the sun
| Ruler¼ Cup of waterSunflowerSunflower seedSoilPlanter|
For starting the lab first place the even amount of soil into the 20 planters. After the planters are equally filled with soil dig a hole in the center of the each planter, 3 cm deep. Place the seeds into the holes that were just dug in the planters, and separate the planters into 10 rain water planters and 10 drinking water planters. When lining the planters up place the planters every other so that they will receive the same amount of light and one not the other receives more than the other (ex. Rain, Tap, Rain, Tap…).
Be sure to place the planters to a window that receives a large amount of natural light. After the lab is all set up then the plants are to be watered with ¼ cup every day at the same time daily (a good amount for them so they are not over watered). The seeds will take time to germinate; they should be checked every day. The measuring is to be started after the sunflowers have broken through the soil and are showing above the soil. For the lab the plants are to be measured everyday at 7pm for the growth from the previous day. After the Experiment has gone for 31 days, look at the results and calculate the average for each of the days and also calculate the standard deviations.
The following experiment supported my hypothesis of sunflowers watered with rain water will grown faster than those watered with clean drinking water from a tap. This is shown in the data I have collected; it is shown when you compare the average heights of the sunflowers during the trials. The average height of the sunflowers being watered in rain water was higher than the flowers being watered in tap water the last day the average height for the flowers watered with rain water was 19.28 cm while the flowers being watered with tap water was only 13.59.
Another indication is that the error bars that are shown on the graph are not as large in the rain water as they are in the tap water and also the rain water flowers heights where closer to one another than the flowers being watered in tap water. The flowers being watered with rain water broke the soil earlier and had a much more rapid increase in height than the flowers watered in the tap water. With all this evidence, it is clear that the experiment supported my hypothesis and rain water allows plants to grow faster than regular clean drinking water.
One of the errors is that the length of time that this experiment was conducted in. The experiment was conducted in 31 days; this amount of time was too short because it takes on average for sunflowers to germinate from7-14 days. This length of time is valuable time that is being wasted from the waiting for the flower to geminate. Another error that can be spotted in the experiment is the lighting. This experiment was done in the month of December. This month has one of the shortest day light hours which created some problems with how fast the plants grew because of the lack of light that they have received.
One improvement in that can be made in my experiment is how the plants were watered. They were all watered with a ¼ measuring cup, but it is hard to have precisely ¼ cup for each plant. This can be better measured with a larger cup that has the labelling of ¼ cup on it. This improvement will allow the water to be measured more precise and will allow equal measuring to each plant. The temperature of the water is another improvement that can be obtained in this experiment. The water that was given to the plants during the 31 day duration was not measured for temperature. The temperature of the water can help the plant with its growing.
The way that this can be fixed is prior to watering the plants be sure to measure the temperature so that the temperature is always the same and there is no flexibility in the temperature of the water. Last improvement that could be made to allow the experiment to be more precise and accurate is for the collection of more data to occur. The way that this improvement could be placed into the experiment is by either extending the length of time of which the collection of data is recorded, another option would be to collect the data twice daily to allow more measurements to be recorded.