What is responsible retention and movement of water in soils?

Cohesion and adhesion forces: These two basic forces are responsible for water retention in the soil. One is the attraction of molecules for each other i.e., cohesion. The other is the attraction of water molecules for the solid surface of soil i.e. adhesion.

What is the process of water moving down through the soil called?

Movement of water into soil is called infiltration, and the downward movement of water within the soil is called percolation, permeability or hydraulic conductivity.

Where will the water go after being absorbed by the soil?

Almost all the water absorbed from the soil by crop roots passes up through the stem into the leaves, where it evaporates and passes into the atmosphere in a process known as transpiration.

What happens to the movement of soil with rain when you change the type of surface cover?

Raindrop impact alone can result in large amounts of soil being moved. However water or wind moving over the surface will remove more soil, and contribute to sheet, rill and gully erosion.

What are the 3 types of water movement in soil?

Generally three types of water movement within the soil are recognized –saturated flow, unsaturated flow and water vapour flow (Fig. 23.1). Water in the liquid phase moves through the water filled pores within the soil (saturated condition) under the influence of gravitational force.

What retains water soil?

Clay soil has small, fine particles, which is why it retains the most amount of water. Sand, with its larger particles and low nutritional content, retains the least amount of water, although it is easily replenished with water. Silt and loam, with medium-size particles, retain a moderate amount of water.

Which factors influence the movement of water through soil?

There are mainly two soil conditions that affect the water vapour movement namely moisture regimes and thermal regimes. In addition to these, the various other factors which influence the moisture and thermal regimes of the soil like organic matter, vegetative cover, soil colour etc.

How does soil drainage affect the water cycle?

Throughflow – Water moves downhill through the soil. Groundwater flow – Water moving slowly through the soil and porous rocks to move back towards the sea. Percolation – Water moving from the soil into the spaces (pores) in the rock.

What happens to the rain water after reaching the ground?

When rain falls to the ground, the water does not stop moving. Some of it flows along the land surface to streams or lakes, some is used by plants, some evaporates and returns to the atmosphere, and some seeps into the ground. The water then fills the empty spaces and cracks above that layer.

How does soil retain water?

Water retention in soil can be understood as the water retained by the soil after it runs through the soil pores to join water bodies such as groundwater or surface streams. Other than percolation through the soil, soil moisture can also deplete due to evaporation directly from the soil and by transpiration by plants.

What is the water movement?

Movement of Water. Movement of Water. Surface movement includes rivers, streams, creeks, lakes, ponds, and human-made “flood” control. All surface water is trying to reach sea level due to gravity. As water flows in channels, the streambed and banks of the channel will resist the flow of water.

What factors affect water movement in the soil?

What affects the water retention curve of soil?

The soil water retention curve can also be influenced by whether the soil is undergoing wetting (sorption) or drying (desorption). When the soil water retention curve differs between wetting and drying, that phenomenon is called hysteresis. This phenomenon has a number of important effects on soil water dynamics.

What is the movement of water in unsaturated soil?

The movement of water under unsaturated soil conditions is due to force of surface tension. Once the flow due to gravitational force has ceased the water moves in the form of thin or capillary film from a wet region to a dry region through finer or micro-pores.

What is the tail of the water retention curve?

In this tail of the water retention curve, large decreases in matric potential are associated with only small decreases in soil water content. Another fundamental characteristic of soil water retention curves is that coarse-textured soils retain less water than fine textured soils at the same matric potential.

What are the water retention characteristics of Sandy and clay soil?

Schematic water retention characteristics for a sandy and a clayey soil during drainage. … Schematic unsaturated hydraulic conductivity functions for a sandy and a clayey soil during drainage. … Measured soil water retention characteristics for a sandy soil exhibiting hysteresis.