The correct option is (c).
Explanation
Soil pH is a critical factor for plant growth, influencing nutrient availability and microbial activity. Most plants thrive in a neutral pH range. When soil becomes too acidic or too basic due to environmental factors or chemical fertilizers, neutralization techniques are employed to restore balance.
Statement-wise Analysis:
- Statement 1 is Incorrect: Plants generally do not grow well when the soil is either highly acidic or highly basic. Most crops require a neutral or slightly acidic to slightly alkaline soil pH (typically between 6.0 and 7.5) for optimal growth and nutrient absorption.
- Statement 2 is Correct: When soil is too acidic, it contains an excess of hydrogen ions. To neutralize this acidity, bases are added. Common treatments include quick lime (calcium oxide) or slaked lime (calcium hydroxide). These substances react with the soil acids to raise the pH towards a neutral level.
- Statement 3 is Correct: When soil is too basic (alkaline), it requires acidification to lower the pH. Organic matter (such as compost or manure) is added to the soil. As this organic matter decomposes, it releases acids which neutralize the excess bases present in the soil.
Key Takeaway:
Soil treatment relies on neutralization: bases (like lime) are used to treat acidic soils, while organic matter (which releases acids) is used to treat basic soils.