Drainage in agriculture

Drainage in agriculture:

Agricultural drainage system drains water from the land to improve crop yields.
It is done by removing water from poorly drained soils by means of surface ditches, subsurface permeable pipes, or both.

Drainage
-Agricultural drainage is the removal of excess water, known as free water or gravitational water, from the surface soil or below to create favorable soil conditions for plant growth.

–“Land drainage is the removal of excess surface and subsurface water from the land to enhance crop growth, including the removal of soluble salts from the soil”.

-Irrigation provides sufficient moisture in the soil for the satisfactory growth of plants, whereas drainage is important for avoiding excess moisture in the root zone

Following are the two types of drainage:

1. surface drainage
2. sub-surface drainage
3. vertical drainage
4. bio-drainage

Surface drainage:  

-Removing the excess water from the land surface is known as surface drainage.

-Adequate arrangement for surface drainage in heavy rainfall areas is essential for speedy water disposal.

Sub-surface:

-Removing the water from the sub-surface or soil profile is known as sub-surface or internal drainage. There should be subsurface drainage in high water table areas.

Two types: 1.Tile sub-surface drainage 2. Mole drainage

vertical drainage:

-Vertical subsurface drainage involves the removal of groundwater through pumped boreholes or tube-wells, either in single or multiple-well configurations.

-The outflow through a tubewell is directed vertically upwards, and if the drawdown is large and the cone of depression is evenly spread (as in uniform coarse soils), there is a substantial component of vertical flow even within the soil profile. Therefore, drainage by tubewells is known as vertical drainage.

Bio-drainage:(AFO-2023)

–All living plants transpire water. The source of the water is either irrigation water or groundwater.

-The transpiration capacity of a plant depends on its species root depth and spread, canopy area, leaf area and leaf structure. When the transpiration is met primarily by withdrawing groundwater, the process is known as biodrainage

-Biodrainage may be defined as “pumping of excess soil water by deep-rooted plants using their
bio-energy.”

Objective of drainage 

Objectives of drainage are stated below:

• Removal of excess water from the soil.
• Arrangement for good aeration in the soil.
• To control the loss of plant nutrients.
• To enhance the activity of soil organisms.
• To improve the soil structure.
• To control soil erosion.
• To prevent salt accumulation on the surface soil.
• To develop favorable conditions for the growth of plant roots.
• To lower the water level below the root zone.