The student conducted an experiment to determine the effect of pH levels on the germination of green bean seeds, planting them in soils with pH values ranging from 2 to 14. Their results showed that beans only germinated in soils with a pH of 6-7, supporting their hypothesis that near neutral pH levels are optimal. This experiment provides useful information for farmers on maintaining proper soil pH for maximum crop growth.

1. Problem: Will Ph levels of growing material, if
changed, from low to high (acidic-basic),
have a positive or negative affect on the
germination of green bean seeds?
(Ph values: 2, 3, 6, 7, 8, 14)
These were the beans
used in the experiment

2.  I chose this project because the aspect of
changing pH levels in a plant’s growing material
really intrigued me
 A second reason why I chose this topic was that I
like to help my parents garden and by finding the
optimum pH range for planting seeds I would be
able to help them a lot
 By conducting this experiment I hoped to be able
to achieve information about what pH levels green
bean seeds would germinate well in and which
ones they do not

3.  To make the best hypothesis, relationships
between pH and plants had to be done
 Research about optimum ranges of pH for
planting trees and plants (6-7)
 Research about how the pH of soil (planting
material) affects the germination of seeds
 Info found about how to change pH of soil
(growing material) (using lime or baking
soda)

4.  After looking through many articles about pH and
germination, the following hypothesis was created
 If green bean seeds are grown in a near neutral pH
level (6-7), then they will germinate the best
(length, measured in centimeters).
Seeds germinating over
a period of time

5.  Control group: a pot of bean seeds grown
in a pot filled with cotton balls with ph value
of 7
 Independent: ph values variable & units: ph
values: 2, 3, 6, 7, 8, 14
 Dependent: length of Bean sprouts variable
& units: length of growth in centimeters
 Control variables & units: amount of water,
sunlight, air, minerals, humidity, cotton balls

6.  Materials used to conduct this experiment were
› Bean Sprout Seeds
› Water
› Ammonia
› Vinegar
› Small Pots
› Cotton balls
› pH strips
› Ruler
› Sunlight
› Baking Soda
› Lime Juice
› Tray

7.  Ask Mrs. Zega to see if she has enough ph strips I could
borrow, or I could buy them from online (Amazon)
 Fill every small pot with 1 mashed cotton ball
 Buy extra cotton balls (in case I run out)
 Pour the ammonia/baking soda or lemon juice into the pots
that need to start out more acidic, or more base
 Make sure the calculation for the ph value in each pot is
correct
 Pour water into the pots with cotton balls which need a ph
value of 7
 Double check each pot with 1 ph strip to see if the ph levels
are correct
 If they are incorrect, retry in a separate dish until you find the
correct ph value
 Keep the ammonia or vinegar/lemon juice near (in case you
need to add more in the pot)
 Place 5 bean sprout seeds in every pot

8.  Rotate the pots every 2 days to make sure the sunlight
distribution will be equal
 Check the height of all 5 sprouts in every pot every 4 days
 Measure all of the lengths of germination for every seed (cm)
 Make sure you keep the same piece of paper in a safe
place(to mark down all heights organizationally)
 Continue step 14 many times until all pots have been
averaged and marked on paper
 At length checking 2, repeat step numbers 13 and 14 again
and mark it down on paper
 Length checking 3, repeat step numbers 13 and 14 again
and mark it down on paper (Use the same paper, or type it
on the computer on a Microsoft Document)
 Take all data and form a chart (if not yet formed from
collecting data)
 Double check the last length measurements and finish the
chart containing the data

9. Picture of pH 7 green beans at 3 days
Picture before experiment was conducted (pots with
mashed cotton balls, no beans yet)

10. Picture during the experiment (7
days after planting green bean
Picture of all pots and all pH at day 4 seeds)
Data of germination kept on
Loose Leaf :D

11. Picture of pH 6, 7, 8, (at day 4)
Picture of pH 14 at day 12

12. Average of Germination length (cm) for all trials which green beans
grew under different pH values
pH values Day 4 Day 8 Day 12
2 0 0 0
3 0 0 0
6 2.2 3.5 6.1
7 1.6 3.5 6.1
8 0 0 0
14 0 0 0

14. pH 2 Average Germination length of beans that Grew
in all Trials
Day/Trials Length(cm)
4 (1) 0
4 (2) 0
4 (3) 0
8 (1) 0
8 (2) 0
8 (3) 0
12 (1) 0
12 (2) 0
12 (3) 0

16. pH 3 Average Germination length of beans that
Grew in all Trials
Day/Trials Length(cm)
4 (1) 0
4 (2) 0
4 (3) 0
8 (1) 0
8 (2) 0
8 (3) 0
12 (1) 0
12 (2) 0
12 (3) 0

18. pH 6 Average Germination length of beans that
Grew in all Trials
Day/Trials Length(cm)
4 (1) 1.5
4 (2) 3.0
4 (3) 2.2
8 (1) 3.8
8 (2) 4.0
8 (3) 2.7
12 (1) 5.8
12 (2) 6.9
12 (3) 5.6

19. 4

20. pH 7 Germination length of beans that Grew
in all trials
Day/Trials Length(cm)
4 (1) 2.0
4 (2) 1.8
4 (3) 1.0
8 (1) 4.0
8 (2) 3.6
8 (3) 3.0
12 (1) 6.0
12 (2) 7.1
12 (3) 5.3

22. pH 8 Average Germination length of beans
that Grew in all Trials
Day/Trials Length(cm)
4 (1) 0
4 (2) 0
4 (3) 0
8 (1) 0
8 (2) 0
8 (3) 0
12 (1) 0
12 (2) 0
12 (3) 0

24. pH 14 Average Germination length of beans
that Grew in all Trials
Day/Trials Length(cm)
4 (1) 0
4 (2) 0
4 (3) 0
8 (1) 0
8 (2) 0
8 (3) 0
12 (1) 0
12 (2) 0
12 (3) 0

26.  The hypothesis was proved correct
 After conducting the experiment, the results showed that pH
levels near 6-7 were the best/only levels where green beans
seeds could germinate.
 Overall, the most significant trend after analyzing the data
was the averages for all trials for pH six and seven because
the results were nearly the same and the pattern was obvious
 It was found that the pH of six grew almost identically to the
pH seven
 To improve this experiment, more controls, such as the same
minerals in all the pots, could have been added.(minerals in
tap water are different than minerals in Lime Juice)

27.  Many farmers need to do similar experiments or
research to find out what the optimum range of pH
is for their crops
 This experiments conclumnsion will most likely
benefit farmers and people engaged in
agricultural experimentations.
 After conducting this experiment, many new
questions about this topic will arise.
› what amount of sunlight is best for plants
› what temperatures will most suit seed germination.
› What pH of fertilizer should be use to get the best results