The adverse effects of waterlogging can be reduced to some extent by supplying nitrogenous fertilizers. The best method of avoiding waterlogging is by providing suitable drainage.

AGRICULTURAL DRAINAGE

Agricultural drainage is the provision of a suitable system for the removal of excessive irrigation or rain water from the land surface so as to provide suitable soil conditions for better plant growth.

Advantages of agricultural drainage

1. Provision of drainage facilitates early sowing of the crop.
2. Agricultural land can be used for a long time without any deterioration due to damaged soil structure and salt concentration.
3. Drainage lowers underground water table so as to facilitate increased root zone depth. Drainage improves soil aeration and increases soil temperature

Drainage for agricultural land is provided by surface and subsurface drainage.

SURFACE DRAINAGE

1. Surface drainage is the simplest and the most common method.
2. Drainage is achieved by digging open drains at suitable intervals and depth.
3. Irrigation channels also serve as drainage channels.

Advantages of surface drainage

1. Provision of surface drainage is cheap.
2. The defects in the open drainage can be seen easily and rectified.
3. It requires less available fall or grade to have an adequate outlet.

Disadvantages in surface drainage system

1. Considerable amount of land is wasted for open drains.
2. These drains cause hindrance to field preparation and intercultivation.
3. The drains get silted and periodical desilting is necessary.
4. Weed growth in the drains is heavy and this has to be removed.
5. Open drains are damaged by rodents and farm animals.

Different methods of surface drainage

Random Field Ditch Method

Standing water may be present in the field at several places distributed randomly. These depressions or micro ponds are connected by mean of shallow channels or ditches and these are led into an outlet.

Land Smoothing

The elevated area is cut off and excess soil is spread over low areas so that the surface is even with uniform slope. Excess surface run off is collected and conveyed into the field ditches provided at the lower end of the field.

Bedding

Small furrows are formed at known intervals parallel to the slope for draining out water. These furrows are known as dead furrows and land between these furrows is known as beds. Small ridges or bunds are made at the centre of the bed with gradual slope to drain water into the dead furrows.

Parallel Field Ditch system

It is almost similar to bedding system except for deep drains and uneven interval between drains.

Broad Bed and Furrow Method

The field is laid out with beds and wide furrows across the slope. About 0.5 per cent slope is provided for the furrows for free drainage. Crops are sown on the beds and furrows help in drainage of water when there is excess rain.