1 Introduction
1.1 PURPOSE OF PROJECT
MAF Policy has identified operational research objectives relating to facilitating resource management to:
"Promote sustainable farm and orchard management planning including the collaborative development of best management practice guidelines."
and has funded a series of projects aimed at meeting these objectives.
The principal objective of this project, which is the second in a series of projects related to irrigation is:
To develop best management guidelines which provide practical information and advice that farmers can use to make, document and revise decisions relating to the design and operation of irrigation systems.
The best management guidelines are to help farmers obtain the benefits of well-designed and operated irrigation systems. These benefits are:
- increased crop production;
- improved environmental performance including reduced contamination of groundwater and reduced impacts on aquatic habitat values in rivers and streams;
- efficient use of resources - water, energy and labour; and
- reduced risk of crop and business failure.
The first project within the operational research objectives funded by MAF Policy (LE Report No 2720/1†) defines sustainability goals for the environmental, social and economic aspects of farming. The report presents a set of indicators that farmers can use to measure and report on the sustainability of their irrigation management practices.
Following the Indicators Report, this, the second project, provides practical guidelines on how to use and apply the indicators to the design and management of irrigation systems. Further projects will assess farmers’ perceptions of current practices, opportunities and restrictions relating to irrigation. The indicators and best management guidelines will be field-tested in the 1997/98 irrigation season.
1.2 APPROACH
The design and operation of irrigation systems requires farmers to make daily, seasonal and long-term decisions within the following main areas:
- new system design;
- preseason checks and planning;
- operation of the system; and
- review of performance.
There are a number of steps in the process. For new designs they are:
- an assessment of whether to irrigate or not;
- finding a water supply;
- determining system capacity, application depths and rates;
- the type of system to use;
- design/purchase/installation; and
- testing and commissioning.
After installation of new systems, and for existing systems, further steps are:
- pre-season checks;
- operating and managing the irrigation system during the season;
- reviewing the performance at the end of the season; and
- maintaining the system.
The decision-making process should lead to the overall goal of irrigation, which usually is to maximise net profit over the long term. The environmental and social goals of irrigation are also very important, but unless the basic economic goal of making a profit is met, irrigation will not be sustainable in the long term.
The correct selection of the system to ensure that it will meet farmers’ needs is vital to the success of irrigation. The design of the system sets the platform for all future operations. How the system is then operated and managed during the season determines the overall success of irrigation.
Daily decisions, such as where to irrigate and how much water to apply must be made. Irrigation strategies, crop choices, and crop priorities for allocating water have to be determined, and the irrigation system must be maintained. In the longer-term, decisions such as applying for changes to or reapplying for resource consents and replacement or upgrading of irrigation equipment must also be made.
Irrigation can be most effective if clear objectives with measurable performance criteria are specified. "What are you trying to achieve and how will you know if you are going in the right direction?"
The Indicators Report provides a formalised set of goals, which defines the objectives of irrigation and addresses the environmental concerns, and economic and social interests of farmers. The indicators recommended in the report are performance measures for these objectives, which can be used to help farmers make informed and defensible irrigation management decisions. Feedback from the indicators can be used to continually improve the sustainability of farming practices and to demonstrate the sustainability of farming practices to regulatory authorities.
A good decision-making process involves a feedback loop such as:
The plan-do-monitor-review process described above is a structured way of continually improving a process and is recommended in both quality assurance and environmental management systems. It creates a cycle by which the consequences of decisions made and implemented can be checked and future decisions altered accordingly.
Farmers can apply this type of decision-making framework to the daily, seasonal and long-term decisions required for irrigation.
In general, farmers should take the seasonal indicators listed in the Indicators Report and set targets or directions for improvement. In the first few years of operating under these guidelines, it will be difficult to set targets and to determine whether an indicator value, such as the production per unit of water, represents good management. With continual use, however, farmers and others will gain a better understanding of how their actions influence the indicator values and it will be easier to set targets and goals. MAF Policy is funding a project in the 1997/98 year to trial these guidelines. These guidelines will provide the means to obtain values for the indicators for the trial farms, and should provide farmers with a starting point for setting their own targets.
1.3 RECOMMENDED INDICATORS
The indicators recommended in LE Report No 2720/1 are summarised below:
| Economic |
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| Environmental |
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| Social |
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The following information is required:
| Daily | Seasonally Or Annually | Long-Term |
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†
Lincoln Environmental Report No 2720/1, June 1997, Indicators of Sustainable Irrigated Agriculture.
Contact for Enquiries
MAF Information Services
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PO Box 2526
Wellington, NEW ZEALAND
Fax: +64 4 894 0721
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