Final answer:
The Bs horizon indicates a concentration of soluble salts, especially sodium. It is a sublayer of the B horizon and usually found in arid or semiarid climates.
Step-by-step explanation:
A Bs horizon in a soil profile indicates a concentration of soluble salts, specifically those that are rich in sodium (referred to as natric horizons). It is a sublayer of the B horizon, where significant accumulation of sodium has occurred, commonly in arid or semiarid climates.
Often, this layer will have a blocky structure due to the impact of the salts on the soil's physical properties. The Bs horizon can affect the soil's fertility and is an important consideration for land management and agricultural practices.