Irrigation is the artificial application of water to plants at a needed period of time. It is also the supply of water to the land for the purpose of agricultural production. Effective irrigation will influence the entire growth process from seedbed preparation, germination, root growth, nutrient utilization, plant growth and regrowth, yield and quality.
Irrigation helps to grow agricultural crops, maintain landscapes, and revegetate disturbed soils in dry areas and during periods of less than average rainfall. Irrigation also has other uses in crop production, including frost protection, suppressing weed growth in grain fields and preventing soil consolidation.
Deciding which irrigation systems is best for your operation requires a knowledge of equipment, system design, plant species, growth stage, root structure, soil composition, and land formation. Irrigation systems should encourage plant growth while minimizing salt imbalances, leaf burns, soil erosion, and water loss. Losses of water will occur due to evaporation, wind drift, run-off and water (and nutrients) sinking deep below the root.
IMPORTANCE OF IRRIGATION.
Irrigation is very important in farming especially when there is no sufficient supply of water. The following are the importance to farmer.
- to grow more pastures and crops
- to have more flexibility in their systems/operations as the ability to access water at times when it would otherwise be hard to achieve good plant growth (due to a deficit in soil moisture) is imperative. Producers can then achieve higher yields and meet market/seasonal demands especially if rainfall events do no occur.
- to produce higher quality crops/pastures as water stress can dramatically impact on the quality of farm produce
- to lengthen the growing season (or in starting the season at an earlier time)
- to have ‘insurance’ against seasonal variability and drought.
- to stock more animals per hectare and practice tighter grazing management due to the reliability of pasture supply throughout the season
- to maximize benefits of fertilizer applications. Fertilizers need to be ‘watered into’ the ground in order to best facilitate plant growth.
- to use areas that would otherwise be ‘less productive’. Irrigation can allow farmers to open up areas of their farms where it would otherwise be ‘too dry’ to grow pasture/crops. This also gives them the capability to carry more stock or to conserve more feed.
- to take advantage of market incentives for unseasonal production
Modern Methods of Irrigation
These are more efficient systems of irrigation that were invented in the recent decades. These help us use water economically without wastage. Let us take a look at the two most important methods.
1. Drip System of Irrigation
The most commonly used method of irrigation these days is the drip method. They lay the pipes in rows near the crops or plants. These plastic pipes have holes in them. Water seeps from these holes drop by drop, hence the name drip irrigation. This is an extremely efficient method of irrigation as it reduces water wastage.
2. Sprinkler System
This system mimics the phenomenon of rain. Water is carried by pipes to central locations on the farm. Sprinklers placed here distribute the water across the fields. This is the most efficient method to irrigate the uneven land. Sprinkler system also provides the best coverage regardless of the size of the farm.
The irrigation system consists of a (main) intake structure or (main) pumping station, a conveyance system, a distribution system, a field application system, and a drainage system.
The (main) intake structure, or (main) pumping station, directs water from the source of supply, such as a reservoir or a river, into the irrigation system.
The conveyance system assures the transport of water from the main intake structure or main pumping station up to the field ditches.
The distribution system assures the transport of water through field ditches to the irrigated fields.
The field application system assures the transport of water within the fields.
The drainage system removes the excess water (caused by rainfall and/or irrigation) from the fields.
A diagrammatic irrigation system.