Correct Option
The correct option is (b).
Explanation
Soil water retention and porosity are physical properties determined by soil texture (particle size) and the content of organic matter (such as manure or humus). These properties are critical for creating a suitable environment for root development and plant growth.Statement 1 is Incorrect: Sandy soil is characterized by large particles and large air spaces, which result in high percolation rates and very low water retention. Manure adds organic matter to the soil, which acts like a sponge and significantly increases water absorption. Therefore, sandy soil has a lower water retaining capacity compared to soil treated with manure.
Statement 2 is Correct: The addition of manure introduces humus and organic material to the soil. This organic matter improves the soil structure and increases its ability to hold moisture. Consequently, the use of manure enhances the water retaining capacity of the soil, preventing it from drying out too quickly.
Statement 3 is Incorrect: Humus (decomposed organic matter) improves soil aggregation, creating a crumb-like structure that increases the space between particles. This makes the soil more porous and improves aeration, rather than making it compact. It prevents soil compaction and facilitates root penetration.
Key Takeaway: Manure and humus improve soil fertility by increasing both water holding capacity and porosity. Sandy soils naturally have poor water retention due to large particle sizes.