Sea water and its effects on Bambusa vulgaris (common bamboo)Featured science projectScience project video

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Complexity level:
4
Project cost ($):
90
Time required:
1 day to prepare, 5 days for observation
Material availability:
Easily found
Safety concerns:

NA

Abstract

This experiment was performed to ascertain if watering Bambusa vulgaris (common bamboo) plants with sea water will cause them to grow faster, slower or wilt. Sea water is sometimes used to put out forest fires. The result of this experiment will help us understand the long term effects of using sea water to put out tropical forest fires.

Hypothesis

 Watering bamboo plants with sea water will cause their growth to be stunted or will cause the plants to wilt and die.

Background

Bambusa vulgaris (common bamboo)

The bamboo plant is known to be very fast growing, as quickly as several inches a day. This plant can achieve its full height in 4 months. This characteristic of the bamboo plant makes bamboo suitable for this experiment. It helps enable us to measure the effect of salt water on ithe growth of bamboo over a short period of time.

Osmosis

Osmosis is the movement/diffusion of water through a partially-permeable membrane from a solution of low concentration to a solution of higher concentration. In this experiment, the"membrane" is in fact the outer layer of the roots of the bamboo plants, as the sea water is absorbed through the roots via the process of osmosis. The high solution concentration consists of sea water and the liquid inside the roots is of lower concentration.

Scientific Terms

Osmosis, partially-permeable membrane, Bamboo, Bambuseae

Materials

 The materials required for this experiment:

  • 15 bamboo plants of equal height
  • 15 pots
  • Soil required for the 15 pots
  • Sea water (enough to water 5 plants twice a day)
  • Tap water
  • Ruler (1 meter long)

Procedure

 

  1. For this experiment, the independent variable the type of water used to water the bamboo plant specimens. The dependent variable is the rate of growth of the bamboo plants. This is determined by measuring the average height of the 5 bamboo plants in each group. The constants (control variables) are the number of times the plants are watered, the amount of water used and the type of plant and soil used.
  2. The bamboo plants are divided into 3 groups with 5 plants in each group. They are labeled as group A, group B and group C.
  3. Group A plants are watered with tap water twice a day.
  4. Group B plants are watered with sea water only once on the 1st day. Subsequently the plants are watered with tap water twice a day.
  5. Group C plants are watered with sea water twice a day.
  6. The bamboo plants are watered as mentioned above and observed for 5 days. Their height is measured everyday and recorded in the table below.

 

Observation

You should observe that the plants in group A will demonstrate fast growth. The plants in group B will show inhibited growth. Finally the group C plants will wilt and die.

Use this table below to help record the bamboo plants daily height (in mm).

Group Plant Day 1 Day 2 Day 3 Day 4 Day 5
A Water twice daily in tap water Plant 1 300mm 455mm 606mm 750mm 903mm
Plant 2 300mm 450mm 599mm 743mm 895mm
Plant 3 300mm 451mm 594mm 745mm 894mm
Plant 4 300mm 445mm 595mm 757mm 905mm
Plant 5 300mm 449mm 606mm 755mm 906mm
Average 300mm 450mm 600mm 751mm 902mm
B Water once only in sea water on 1st day. After that water twice daily in tap water Plant 6 300mm 305mm 327mm 357mm 397mm
Plant 7 300mm 317mm 330mm 360mm 402mm
Plant 8 300mm 3045mm 336mm 366mm 405mm
Plant 9 300mm 311mm 332mm 362mm 405mm
Plant 10 300mm 308mm 331mm 365mm 401mm
Average 300mm 314mm 332mm 364mm 389mm
C Water twice daily in sea water Plant 11 300mm 304mm 304mm 304mm 304mm
Plant 12 300mm 307mm 307mm 307mm 307mm
Plant 13 300mm 302mm 302mm 302mm 302mm
Plant 14 300mm 305mm 305mm 305mm 305mm
Plant 15 300mm 311mm 311mm 311mm 311mm
Average 300mm 307mm 307mm 307mm 307mm

Use the graph below to plot the results of above observation.bamboo growth statistics

Conclusion

The hypothesis is proven to be true. Watering bamboo plants with sea water causes a stunted growth or kills the plant.

Sea water is sometimes use to put out forest fires. It may help to put out fires but in turn, adversely affects the growth of the plants that survive the fire. It is advisable to use fresh water if it is available.

Also consider

What would happen if the experiment was varied by using brackish water or water from freshwater lakes or ponds?

The experiment can be repeated using different plants such as bean sprouts, radishes and other fast growing plants.

References

 Bamboo - http://www.en.wikipedia.org/wiki/Bamboo

Can you water plants with salt water - http://www.ehow.com/facts_5509396_can-water-plants-salt-water.html

Osmosis - http://en.wikipedia.org/wiki/Osmosis

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