Getting drip irrigation right

Saturday March 14 2020

A woman checks on set drip irrigation pipes at

A woman checks on set drip irrigation pipes at her farm in Kitgum When buying drip lines, consider quality, durability and the flow rate of water. Photo by Lominda Afedraru  

By Lominda Afedraru

It is now common knowledge that rain-fed farming is no longer viable.
Most farmers are, therefore, going for irrigation systems to give their crops sufficient water as the dry spell bites. But even as many take up the technology, few farmers know how to efficiently use the various irrigation systems for more yields.
Seeds of Gold team visited farmer Jackeline Apio in Kitgum when she had just harvested her bulb onions. She proudly informed us that she harvested about seven tonnes per acre.
Well, Seeds of Gold could share her joy but the harvest was quite below the expected yields of 16-20 tonnes per acre.

What went wrong?
One of the things to which we attributed the low yields was the irrigation scheduling, which Apio said she had a problem with. According to her, she watered her crops every day using the drip irrigation systems for about 20 minutes.
The recommended watering duration using the drip irrigation system for her area is two hours, three times per week, but it depends on the weather conditions.

Drip is the commonly used irrigation system in Uganda, with the others being overhead and surface irrigation. The choice of an irrigation method depends on the topography of the land, availability of water, variations in soil types, and source of power to pump water, on-farm storage capacity and capital required.
Seeds of Gold did interact with Ms Claudia Talemwa the marketing coordinator of Solar Now, a company specialised in providing solar powered irrigation pumps to farmers.

It is recommended that farmers engage irrigation agronomists before buying the equipment. These agronomists visit your farms and advise accordingly. They are looking for features such as presence of water source at the farm.
“The irrigation system layout is critical on a farm set-up since the design and performance should be in line with irrigation scheduling to enhance the farmer’s skills to control and manage the system more efficiently,” says Talemwa.

Ideally, it’s important to water early in the morning or late in the evening as this helps the plants to absorb water. Watering when the temperatures are too high results in water loss due to evaporation. Before watering, the farmer should do a simple water test by feeling and observing the appearance of the soil and the crops. Usually the team recommends water source which include spring water, rivers, lakes or rain water harvesting which is kept in a reservoir.

Once this is established the farmer is advised to purchase the type of water pump which is suitable to the farm depending on its location and the water source.
For heavy duty pumps which are fixed, they have the capacity to pump water at a radius of 10 kilometres or more meaning the farm must be relatively on large scale. Those none movable pumps are heavy duty and recommended for large scale farming.


Water pumps
There are two different medium pumps affordable to small scale farmers but there are also types that can be purchased by farmers in most cases they are fixed pumps that are installed in one place.

Portable pumps
Most farmers prefer to call them the rain maker solar pump because the pressure for pumping water is so high. It can pick water from 100 metres and it will pump at a radius of 6.6 metres. It costs about Shs2.9m. This machine pumps 700 litres of water per hour. It is appropriate for a farmer to have a water reservoir facility close to the farm where water can be pumped from the source of origin to the reservoir. This can be pumped to the farm at any one time.

SF2 solar pump
This is another portable pump whose panels can be folded and it is easy moving it. Once a farmer completes the irrigation process for the day, it will simply be folded and kept either in a house or a safe place waiting to execute the next duty.
It has capacity of pumping water at 500 metre radios and it contains a component of three sprinkler provision. It costs Shs3.9m. The machine can pump 3,000 litres of water per hour.

This is done by squeezing soil into a ball and creating a ribbon between the thumb and the fore fingers.
Sticky means that it is well watered while loose soil shows one should irrigate the crops. The visible appearance of crops such as leaf colour, curling of leaves and the ultimate wilting, also acts as a guide to determine the amount of water required by the plant.
The number of times to do the watering a week also depends on the growing stage of the crop. For instance, during the early stages of growth and when forming bulbs, onions require adequate water, unlike at harvesting time when they require curing.

Overwatering often leads to wastage, rise in pests and diseases such as damping off, which increase a farmer’s cost of production. When buying drip lines, consider quality, durability and the flow rate of the water. One should also ensure that the drip lines used are from reliable supplies. Blocked emitters can be cleaned by flushing the drip lines, gently knocking the emitters while water is running or fertigate using phosphoric acid to clean the emitters. The length of the drip line must also be considered when laying out the lines.

All the pumps contain components which include solar panels, the switch, and the mortar which generates pumping of water and delivery pipes which deliver water that is sprinkled on the crops.
Apart from pumping water, a farmer may decide to build on the machine and install gradgets such as lighting bulbs, sockets for charging phones and for cooking among others so that the pump becomes multipurpose.
The team usually guides and advices farmers on which type of pipe to use for pumping depending on the source of water and size of the farm including the type of plant.
Farmers are advised to carry out irrigation during dry season. Once the rains are dropping there is no need to carry out irrigation.