Biology · Ecosystems · NEET
Leaching is a physical washing-down process, not a microbial chemical breakdown. Water dissolves the inorganic nutrients and carries them down into the soil. Compare this with catabolism and mineralisation, which are chemical steps done by microbial enzymes. For NEET, remember: leaching only moves nutrients, it does not break bonds.
They are opposite in effect. Mineralisation releases inorganic nutrients into the soil (makes them available), while leaching sends water-soluble nutrients down and precipitates them as unavailable salts (locks them away from plants). This exact contrast is a common NEET trap in match-the-column questions.
Leaching effectively removes usable nutrients from the top soil where roots feed. The dissolved nutrients move down the soil horizon and precipitate as unavailable salts, so plants can no longer take them up. That is why leaching is seen as a nutrient-loss step in decomposition.
No. Fragmentation is done by detritivores like earthworms that break detritus into smaller particles. Leaching is the water-soluble nutrients washing down into the soil. Both are steps of decomposition, but they are different steps. NEET 2023 tested this exact distinction.
Precipitated means the dissolved nutrients settle out and become solid salts. 'Unavailable' means plant roots cannot absorb them anymore. So during leaching the nutrients are not destroyed, they simply become locked in a form plants cannot use. This wording comes straight from the NCERT line.
Identify the correct statements: A. Detritivores perform fragmentation. B. The humus is further degraded by some microbes during mineralisation. C. Water soluble inorganic nutrients go down into the soil and get precipitated by a process called leaching. D. The detritus food chain begins with living organisms. E. Earthworms break down detritus into smaller particles by a process called catabolism. Choose the correct answer:
Try the real previous-year questions from this chapter — each with the answer and a full solution.
The steps in order are fragmentation, leaching, catabolism, humification and mineralisation. Leaching is the second step, right after detritivores fragment the detritus.
Because the water-soluble nutrients move down the soil horizon and precipitate as unavailable salts, plant roots in the upper soil can no longer absorb them. This is a small loss from the plant-available pool.
No. Leaching is a physical process driven by water. Microbes drive catabolism, humification and mineralisation. This difference is important for NEET match-the-column questions.
Leaching = water-soluble nutrients go down into the soil and get precipitated as unavailable salts. Learn this exact NCERT wording because NEET asks it word-for-word.
