Question

Which of the following characteristics is not a function of humus in soil?
A. Provides nutrients
B. Raises pH
C. Retains moisture
D. Humus does all of the above in soil

Answer 1

Hint: Humus is defined as theblack, organic material that forms in soil when plant and animal matter decays. Plant matter includes leaves, twigs, barks and other materials. When a plant drops these materials into the ground, it piles up to form moist humus. In addition to the plant materials, humus is also composed of materials from decaying animals like insects, rodents and earthworms.

Complete explanation:
Option A Provides nutrients: Humus provide nutrients that are released after their breakdown by microorganisms. Humus is rich in nitrogen, sulphur, phosphorus oxide which are all important nutrients for the soil and organisms that depend on soil for life, like plants and microorganisms.
Option A is incorrect.
Option B Raises pH: One of the important characteristics of humus is they act as a buffer in excessive acidic or alkaline soil conditions. It does not raise or lower the pH of soil.
Option B is correct.
Option C Retains moisture: Humus has the ability to withhold about its weight in moisture and therefore increases the capacity of soil to withstand drought.
Option C is incorrect.
Option D Humus does all of the above in soil: This option cannot be chosen because, one of the options that humus raises pH is wrong.
Option D is incorrect.

Hence the correct answer is option B. Raises pH

Note:
Humus can make the soil more fertile. It also has the ability to prevent disease in plants and food crops. Humus soil is usually crumbly in nature. This allows the air and water to move easily through the soil and enables oxygen to reach the roots of plants.Humus can be produced naturally or artificially through composting. In composting decaying organic material, such as food and garden wastes are collected and turned into soil.