Question

Give reasons for the following.

Deltaic alluvium is more fertile than the inland alluvium.

Answer 1

1. Regular replenishment by river floods deltaic alluvium receives fresh silt every flood/season, so nutrients are constantly renewed.
2. Finer texture (more silt & clay) the depositional conditions in deltas produce fine, uniform particles that hold water and nutrients better than coarser inland deposits.
3. Higher humus/organic content deltaic deposits (especially major river deltas) accumulate plant/organic matter, improving fertility and soil structure.
4. Richer in soluble minerals (potash, lime, iron, magnesia) deltaic/alluvial sediments commonly contain these crop-available minerals.
5. Less of the infertile reworked material found in older inland alluvium inland (bhangar/older) alluvium often contains kankar (lime nodules) and is not replenished frequently, so it is comparatively less fertile.
6. Greater depth and uniformity of deposition in delta plains thick, even layers of recent alluvium give deep, productive rooting zones for crops.