How do you select a good place to plant a tree in your school/ at home? Test the soil and investigate and write a report on it.
To select a good place to plant a tree in our school/at home. First of all, we have to take the following things into consideration
pH of the Soil:
Plants require a specific pH range for their healthy growth. Different plants need different pH values to grow naturally. Most of the plants grow when the Soil pH is around 7 i.e., Neutral. So, we have to understand what is pH first.
What is the pH scale?
A scale for measuring hydrogen ion concentration in a solution is called the pH scale.
What is pH?
pH is a measure of how acidic or basic water is. (in our case soil). The range of the pH scale is from 0 to 14. The number 7 is Neutral. A pH less than 7 indicates acidity, and a pH above 7 indicates a base(alkaline).
As discussed above, many plants grow when the soil pH is Neutral or slightly acidic, whereas some plants grow in acidic soil and some plants grow in alkaline soil.
Now the question is how to determine the pH of the Soil.
How do you find out your soil pH?
There is an activity (activity 13) in the Acids and Bases chapter of the Class 10th Physics textbook. The method in the Physics textbook is:
- Put about 2g of soil in a test tube and add 5 ml of water to it.
- Shake the contents of the test tube.
- Filter the contents and collect the filtrate in a test tube.
- Check the pH of this filtrate with the help of Universal indicator paper.
What is Universal Indicator Paper?
The Universal indicator is a mixture of several indicators to identify the pH of a solution. It shows different colours at different concentrations of Hydrogen ions in a solution.
DIAGRAM of UNIVERSAL INDICATOR
Universal Indicator shows GREEN Colour for Neutral Solution (in our case soil),
And it shows red colour for strong acid, whereas Violet Colour for Strong base.
The Universal Indicator Chart is as follows
| pH Range | Colour | Description |
| 0-3 | Red | Strongly Acid |
| 3-4 | Orange | Acidic Nature |
| 5 | Yellowish Orange | Weak Acid |
| 6 | Yellow | Slightly Acid |
| 7 | Green | Neutral |
| 8 | Blue-Green | Slightly Basic |
| 9 | Blue | Weak Base |
| 10-14 | Violet | Strong Base |
What is the Ideal Soil pH for the growth of plants in your region?
The ideal Soil pH range for the growth of plants is 5.5 to 7. Because most of the minerals and nutrients are more soluble in the slightly acidic and neutral soil when compare to acidic soil.
So, the ideal Soil pH for the growth of plants is 5.5 to 7. But some plants can grow in acidic soil and others in basic (alkaline) soil.
Plants that prefer Acidic soil
Plants like blueberries, raspberries, radishes, and sweet potatoes prefer acidic soil.
Plants that prefer Basic Soil
Normally, the higher the pH value the more it will hinder the growth of the plants. But some plants can be grown in slightly Alkaline Soil.
Namely, Asparagus, Beans, Gourd, Cauliflower, Garlic etc.,
One of the best examples of plants that prefer Basic soil is Dates. Dates farming needs Soil pH from 8 to 10.
Under what soil conditions a farmer would treat the soil of his fields with quicklime and Calcium Carbonate
If the soil is acidic and it is unsuitable for agriculture then the farmer can treat the soil of his fields with quicklime i.e., calcium oxide and Chalk i.e. Calcium Carbonate.
The Plants that adapt to a range of pH levels
Hydrangeas produce different coloured flowers depending on the nature of the soil they are grown in(Soil pH). With a pH lower than 6 it yields blue colour, and if the pH is above 7 it yields pink or red colour.
Importance of Soil pH
From the above discussion, we understand that the pH of the Soil is very important which most people ignore while planting and gardening. Because of this, the plants will not give flowers or fruits as expected.
What is soil pH?
Simply, Soil pH is the measure of acidity or alkalinity of the soil.
Soil pH is important because the acidity or alkalinity of the soil determines which plant nutrients are available to the roots of plants.
Nitrogen, Phosphorus, and potassium -the plants’ nutrients in the soil will dissolve in water or soil moisture.
Most Plant nutrients will not dissolve when the soil is too acidic or too basic.
So, for growing plants in our region, we should know the Soil pH of the region and we should grow the plants with the like pH needs, similar temperature tolerance and similar nutrient needs.
Factors that Affect Soil pH?
Some of the Factors that affect soil pH are
- Climate
- Mineral Content
- Soil texture
What causes High Soil pH?
High Soil pH or Soil Acidity is caused by one of the reasons
- Leaching due to heavy rainfall
- Acidic parent material
- Use of Fertilizers like Ammonium Sulphate and Ammonium nitrate
Besides these reasons, some soils naturally have High Soil pH or Soil Acidity.
How Do You Adjust Soil pH?
If the soil is too acidic or too alkaline, then we can adjust the pH level of the soil. If the soil is acidic, we have to raise the pH level of the soil whereas if the soil is basic or alkaline then we have to decrease the pH level of the soil.
What is used to raise the pH level of the soil?
If the soil is acidic, then we have to raise the pH level of the soil for planting a tree. To achieve this, we have to use Quick lime or calcium carbonate as discussed above.
What is used to lower the pH level of the soil
If the soil is alkaline or basic, then to plant a tree in this soil we have to decrease the pH level of the soil. This can be achieved by using Elemental Sulphur, Aluminum Sulphate, Iron Sulphate, and ammonium sulphate in the soil.
Why should we monitor soil pH?
It is very important to monitor the soil pH of our garden because
- Soil pH affects nutrient uptake i.e., it determines the availability of almost all essential plant nutrients
- If soil pH is too acidic then certain nutrients become less available
- Soil pH affects crop yields
So, it is most important to monitor the soil pH.
A Report on selecting a good place to plant a tree in the school/ at home
From all the details discussed above, we can conclude that a good place to plant a tree in school or at home is the soil which is neutral or slightly acidic. The optimum soil pH range for planting a tree is from 5.5 to 7.
If the soil is acidic then add quicklime to raise its pH value whereas if the soil is too basic then add aluminium sulphate to decrease its pH value.
Also, we have to know the pH of the plant (flower, crop, fruit, vegetable) we are growing. And grow the same pH plants together for better results.
Soil pH plays an important role in growing plants because the nutrients for plants are absorbed by plants from the soil and for this, we have to take care of soil pH.