The agricultural sector consumes significant amounts of water. It is important that certain water management principals must be in place to make sure water will be there for the future farmers of South Africa.
In South Africa water is a critical resource for which there is growing competition between the urban, industrial and agriculture sectors. The National Water Act (NWA) of 1998 states fresh water should be used efficiently. The NWA prioritises water use for basic human needs and for protecting aquatic eco-systems, with agriculture having a lower priority. Nonetheless, agriculture is of high economic importance as it contributes to food security, income from exports, employment and ensures that people are able to make a living.
Water efficiency can be enhanced through either engineering practices (including the modification or upgrading of the water supply infrastructure and operating systems) or changes to behaviour regarding our water use habits.
Before we discuss water-efficient practices here are a few questions you can ask yourself:
- What is the problem to address?
- Which one (or both) of the practices above might be used to solve the problem?
- How effective is the solution?
- What is the cost involved?
- Where has the solution been used successfully?
The tools you use and water management: Engineering Practice for Irrigation
Management: This include collecting data to understand the amount of water being used and where it is used, as well as soil moisture monitoring and water conditions. With this information farmers can make informed decisions on the application of water. Methods like checking the efficiency of water pumping, evaluating soil moisture, scheduling irrigation and measuring the rainfall of the area should also be used.
System modifications: When a system starts to use more water without reason, modification or replacement of the system should be considered. This is often more expensive than investing in efficient field practices and management strategies. Modifications could include changing pump sizes, adding drop down tubes to a pivot system or changing sprinkler heads.
Behavioural Practice (What you do)
These strategies do not require changing irrigation equipment, but focus instead on how this equipment is used. Optimising the scheduling of water application (rates and timing) could result in reduced water use while producing the same yield. Here follow questions you can ask yourself when making these decisions:
- What is the electricity cost of pumping water for irrigation?
- What is the rainfall in that area and crop demand?
- What is the limit on the irrigation system for pumping water?
- What is the water storage capacity of the soil you are irrigating?
- Can the water be re-used for something else and how can I use it?
Before investing in an irrigation system, it is important to understand the benefits of the different irrigation systems options, and how these might apply to your situation and needs. Below are some examples of options for irrigation for your consideration:
- Drip irrigation: The application of water directly where it is needed.
- Micro sprinklers and sprayers: These operate at low pressure and spray water on a specific area. They are used where drip irrigation is not possible.
- Pivots: When a large area needs to be irrigated these are the ones to use
Water Use Planning:
Ecosystem Management plan in the Western Cape:
Water tools to use to help you to use water more efficiently and save on your irrigation:
For ideas on waste water treatment:
Water Verification guide:
Verification is a process to check the volume of water registered by existing users and its lawfulness under previous legislation, so as to certify the extent of Existing Lawful Use (ELU).
The guide explains:
- How the lawfulness of Existing Water Use is determined, through the process of verification
- How this forms part of Water Resource Management
- Commonly asked questions about verification
Hortgro Irrigation Seminar
HORTGRO Science recently held an Irrigation Seminar at Allée Bleue in Groot Drakenstein. The seminar was held to address the current drought conditions in the Western Cape, and to provide producers with coping strategies.
To view all the complete presentations, visit our YouTube channel here.
Or download the Irrigation Seminar Summary Report here.