Question

The water holding capacity is highest in ____.
A.Mixture of sand and loam
B.Loamy soil
C.Sandy soil
D.Clayey soil

Answer 1

Hint: Water holding capacity of a soil is primarily controlled by the texture of the soil and the organic matter present. Larger the surface area of the soil particles, higher is its water holding capacity.

Complete step by step answer:
The water holding capacity of a soil is a very important characteristic of a soil. Soils that hold sufficiently good amounts of water are less susceptible to loss of nutrients and pesticides through leaching. This is so, because a soil with a relatively less water holding capacity reaches the saturation point much sooner than a soil with a higher water holding capacity. After the soil is saturated with water, all of the excess water, nutrients and pesticides that are in the soil solution leach downward in the soil profile.
Small sized clay and silt particles have a larger surface area than large sized sand particles. The large surface area of the clay particles allow them to hold a greater quantity of water.
Thus, the water holding capacity is the highest in clayey soil due to large surface area as well as the tightly packed particles that restrict the water from percolating.

Therefore, the correct option is D.

Note:
Organic matter in the soil is another factor that affects the water holding capacity. Organic matter has a natural magnetism towards water. If we increase the percentage of organic matter in soil, the water holding capacity of the soil will increase. Organic matter is decayed material that originates from living organisms. It can be increased by addition of plant or animal material.