Choosing the right irrigation system for your crop is a key determinant of your productivity. In the same manner that a farmer chooses the right seed, works the soil the right way, and grows in the right weather, so is your choice of irrigation method.
There are several factors that inform the decision to an irrigation method, and ultimately to the right irrigation system. Below, Grekkon Limited explains the factors they advise growers to consider when making this irrigation decision. In this piece, we consider factors that influence the use of farrow/ basin irrigation, overhead irrigation, and drip irrigation methods.
- Amount of water available
Every irrigation method has a different water consumption rate than the other. Those methods that use less water to achieve the same yield, or higher are referred to as water efficient irrigation methods.
- Farrow or basin irrigation. It is the practice of flooding farrows or basins in which crops are planted. This method is common in places where there is plenty of irrigation water, such as rice paddies. It is the oldest known irrigation method. No special technology or technique is required here as it only requires basic tools to operationalise. However, it is the most water inefficient method of irrigation because, over 30% of the water applied is lost to evaporation. Minerals are heavily leached into the ground, which increases the cost of fertilizer, which is frequently added to compensate for this loss. Basin irrigation is labor intensive.
- Overhead irrigation. This is the use of overhead sprinklers, the pivot system and the rain hose kit. This system too requires large amounts of water.
- Drip irrigation. It is the most water efficient irrigation method. This is because it delivers water to the base of the plant- in drops. Drip systems can be either surface or sub-surface. Drip irrigation on vegetables is by pre-perforated drip lines, while on trees and orchards is by the use of online drippers or button drippers.
- Crop type
Most crops will do well with basin irrigation. However, some exceptions such as strawberry will not.
Solanaceous crops such as tomato, potato, and cucurbits are highly susceptible to fungal infections if moisture remains on the leaf surface for a prolonged amount of time. This is why overhead irrigation is discouraged in such crop types.
Drip works well with all crops. However, where higher humidity is required during the growing period, then overhead irrigation will be used.
- Land size
Basin irrigation is carried out on medium to large scale growing. Sprinklers are used from small kitchen gardens to large scale growing. They differ in size according to the amount of water needed.
The pivot system is used on large acreage only. The rain hose kit is for nurseries, and small to medium acreage.
- Growing method
Whereas a grower can choose any of these irrigation methods for his or her open field crop, a greenhouse grower is limited to the drip irrigation method only.
Basin irrigation is the cheapest way to irrigate, while drip irrigation, and pivot irrigation systems are the most expensive to procure.