LectureTopic25-PlantandSoilNutrition

A horizon

The top layer of soil containing decaying organic matter and microbial organisms.

B horizon

The layer of soil that consists of less weathered material beneath the A horizon.

C horizon

The layer of soil that consists of rock or 'parent material' from which the soil is derived.

Cation exchange

The process by which cations are exchanged between soil particles and root hairs.

Membrane potential

The difference in charge across a cell membrane that can drive the transport of solutes into the cell.

Cotransport

The transport of one substance across a membrane coupled with another substance.

Humus

Organic matter in topsoil composed of decaying plant and animal material.

Macronutrients

Essential elements needed by plants in large quantities, such as C, H, O, P, K, N, S, Ca, Fe, Mg.

Micronutrients

Essential elements required by plants in small quantities, such as Cl, Mn, B, Zn, Cu, Ni, Mo.

Nitrogen-fixing bacteria

Bacteria that convert atmospheric nitrogen into forms that plants can absorb.

Endomycorrhizae

Mycorrhizal fungi that penetrate plant roots and form arbuscules for nutrient exchange.

Ectomycorrhizae

Mycorrhizal fungi that form a sheath around plant roots without penetrating them.

Epiphytes

Plants that grow on other plants and obtain nutrients from the atmosphere and canopy soil.

Parasitic plants

Plants that absorb water, minerals, and sometimes carbon directly from their host.

Carnivorous plants

Plants that capture and digest small animals to supplement their mineral nutrition.

Soil conservation

Practices aimed at preventing soil degradation and maintaining its health, often through sustainable agricultural methods.

Nutrient deficiency symptoms

Visible indicators of lack of essential nutrients in plants, such as yellowing or stunted growth.