compare the feature of the A and B horizon of the soil
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Answer:
1. Horizon A or Topsoil
It is also called the humus layer, which is rich in organic material. This layer consists of decomposed material and organic matter. This is the reason, the topsoil has a dark brown color. The hummus makes the topsoil soft, porous to hold enough air and water. In this layer, the seeds germinate and roots of the plants grow. Many living organisms like earthworms, millipedes, and centipedes, bacteria, and fungi are found in this layer of soil.
2. Horizon B or Subsoil
Just below the topsoil lies another layer called subsoil or horizon-B. It is comparatively harder and compact than topsoil. It is lighter in color than the topsoil because there is less humus in this layer. This layer is less organic but is rich in minerals brought down from the topsoil. It contains metal salts, especially iron oxide in a large proportion. Farmers often mix horizon-A and horizon-B when ploughing their fields.