1School of Environment and Agriculture, University of Western Sydney, Locked Bag 1797
Penrith South DC, NSW 1797, Email: b.maheshwari@uws.edu.au
2New South Wales Agriculture, Locked Bag 11, Windsor, NSW 2756
Email: matthew.plunkett@agric.nsw.gov.au
Hawkesbury – Nepean Catchment (HNC) is an important peri-urban farming area for the supply of fresh vegetables, fruits, turf and other farm products to growing population of Sydney Metropolitan Area (SMA). The catchment is extremely important for the people of SMA as it is an important source of water for over four million who live in the area. The pressures of urbanisation in the SMA have increased demand for water, and as a result there is now an increased competition for water among different users in the catchment. The water industry reforms currently underway will further exacerbate the situation through reduced allocation and increased price of water for irrigation. It is now increasingly being accepted that irrigators need to employ ways to use water more wisely and access alternative water supplies. One of the possible ways to conserve water is improve the practice of irrigation scheduling by individual farmers. Thirty irrigators from the HNC were surveyed to investigate how they perceive the currently available irrigation scheduling devices and procedures and how they make scheduling decisions as a part of their irrigation management strategy. The crops considered in the study include fruits, vegetables, pastures, turf, olives, nursery and cut flowers. A number of factors that affect irrigation scheduling in the area were identified, including the limited understanding of soil-water-plant relationship, cost of monitoring soil-moisture and accommodating irrigation activity with other farm tasks. In most cases, irrigators’ own experience of irrigation practice played an important role as to the irrigation scheduling decision. The study highlights some key irrigation scheduling issues that need to be addressed by research and advisory bodies for improving irrigation management in the future.
Introduction
The Hawkesbury – Nepean Catchment (area 22 000 km2) is an important natural asset, providing valuable agricultural, environmental and economic benefits to the people of the Sydney Metropolitan Area (SMA) (Figure 1). There are about 4 million people in the SMA and nearly half of them (1.8 million) live in the HNC. The catchment in the north and northwest are undeveloped, rugged and forested; whereas, the flatter area in the west and southwest, originally agricultural land, is now generally urbanised (Bickford and Smith, 2002). Irrigated agriculture in the HNC accounts for only 1% of the total catchment area, but it has been very important in supplying fresh vegetables, fruits, turf and other farm produce to the SMA.
Irrigation activity in the HNC dates back to 1828 and has continued to grow. The area under irrigation by 1976 was about 18,000 ha (Rosen, 1995), and in the next 25 years this increased to 19,000 ha with a total number of irrigation licences about 1600. Most irrigated agriculture in the HNC relies upon water from the largely unregulated Hawkesbury – Nepean River System and from water stored in farm dams. Demand for water by irrigated agriculture increases during summer months (December – March), indicating that the demand is greatest when the flow in the river system is least. Irrigation is mainly done using fixed, hand shift, lateral move and travelling sprinkler systems. It was estimated that the annual value of irrigated agriculture in the catchment could be as much as $484 million (NSW Agriculture, 2002).
The dependable catchment yield of water for the SMA is about 600 GL a year, and the average reticulated water consumption in the area is 625 GL per year (Yiasoumi, 2003). This is clearly not a sustainable situation in the long term. It was recently agreed that irrigation efficiency gains of 15% will be required in the HNC to improve the sustainability of the Hawkesbury Nepean river system over the next 10 years. Strategies are being developed across all industries to reduce the demand on water supplies. Pressure is likely to intensify on all industries to demonstrate that they are using water efficiently.
Irrigated agriculture in the peri-urban areas of the HNC is under pressure to improve irrigation efficiency, recycle water, and maintain nutrients on farm. Environmental performance is becoming increasingly important priority for the government agencies and farming community. Education continues to be critical in raising awareness of the community’s capacity to be efficient in water use.
Figure 1. Hawkesbury-Nepean Catchment.
Research and extension programs in the HNC are increasingly focussing on developing strategies that will help grower’s ability to improve production, save water, and improve crop quality. Minimising the leaching of nutrients through the soil or into surface waterways and improving water quality are also important. In this study, we examine why irrigation scheduling is poorly adopted in the HNC and implications of this for future practice both in research and extension domains. The key objectives of the study are:
- How do farmers in the Hawkesbury – Nepean Catchment schedule their irrigations on their properties?
- What are the barriers to the adoption of irrigation scheduling? and
- What are the implications of their current irrigation practices for the future irrigation research and extension programs?
Water Wise on the Farm Program
The Water Wise on the Farm Program is an education and awareness campaign designed to build partnerships and work with the irrigation industry. Its primary role is to improve the economic and environmental sustainability of irrigation farms in NSW through the development and adoption of best irrigation management practices and technologies. The program was initiated by NSW Agriculture in 1995, in response to the suite of state and federal water reforms, including the Council of Australian Governments water reform agenda. In 1998, a network of eight facilitators was employed to work with all industries reliant on irrigation, one of which is based in the HNC. The program is currently funded until 30th June 2005.
The program is part of the Water Reform Structural Adjustment Program (WRSAP), which includes irrigation training, and up until August 2003, a financial assistance package for irrigators to adopt best irrigation practice. This package included the development of an irrigation and drainage management plan (80% cost up to $12,000), upgrading current or existing irrigation systems (50% cost up to $15,000) and for irrigation scheduling (50% cost up to $2,000). To access the funding, trainees had to complete some form of irrigation training. Part of the WRSAP charter was to offset the impacts of changes to the way water is delivered, licensed, priced and accessed by irrigators.
Over 4000 irrigators in NSW have completed the 4-day ‘Introduction to Irrigation Management’ course. The course is designed to expose irrigators to irrigation management issues that affect effective and ecologically sound irrigation management on their farms as well as to provide irrigators with the knowledge and skills to adopt improved irrigation management practices.
In the HNC, 200 irrigators have completed the training, 90% stating they had changed their behaviour in the way they irrigate now. However, a very small percentage of irrigators who completed the training accessed the financial assistance package, including the irrigation-scheduling grant to adopt better practice. A statewide review is currently being undertaken to determine the low level of adoption, and guide the direction of the program beyond 2005.
Other projects the program conduct in NSW are: water use efficiency projects with the vegetable industry, and facilitating funding for the development of water projects with irrigator groups. Also, the program promotes best practice irrigation through farm competitions, give advice on dairy wastewater management, coordinate educational events such as field days, farm walks and provide technical advice to irrigators on all facets of irrigation system efficiency.
Water Industry Reforms and their Impacts
The State Government of New South Wales initiated water industry reforms for a better management of water resources in NSW in late 1999 through a white paper that later culminated into the Water Act 2000 (DLWC, 2000). The main theme of the paper was ‘sharing the water resource’ with an aim to protect the water environment, strengthen community and government partnerships, effective administrative procedures, equity in water access and mechanisms for water trading and transfer arrangements.
One of the important and contentious steps the State Government had to take to implement water reforms was to limit the use of runoff generated from the individual farms through the development of the Farm Dams Policy. The policy limits farmers to store and use up to 10% of runoff from their farms before requiring a licence, and the rest must be allowed to flow naturally out of their properties to feed the local river system. Like other catchments in the state, the policy has greatly influenced the access and use of water by irrigators in the HNC and has added another dimension to their difficulty alongwith the impacts of urbanisation.
In general, the Water Act 2000 and related policies have put irrigation in the HNC under greater scrutiny. Irrigators will now have their entitlement reduced and be required to pay more for their water use. This poses a serious threat to the future viability and retention of irrigation industry in the HNC. Irrigators are cynical and concerned about the new policies and regulation resulting from the water industry reforms.
Study Area
Agriculture in the HNC is a mix of extensive and intensive industries that mainly include dairy farms, orchards, vegetable, turf farms and nurseries. About one-quarter of the total number of farms have their area less than 10 ha, a little over one-third of them have between 10 and 100 ha, about one-third between 100 and 1000 ha, and a small proportion have more than 1000 ha (NSW Agriculture, 2002).
Irrigation activity in the HNC dates back to 1828 and has continued to grow. The area under irrigation by 1976 was about 18000 ha (Rosen, 1995), and in the next 25 years this increased to 19000 ha with a total number of irrigation licences about 1600. Most irrigated agriculture in the HNC relies upon water from the largely unregulated HNRS and from water stored in farm dams. Demand for water by irrigated agriculture increases during summer months (December – March), indicating that the demand is greatest when the flow in the HNRS is least. Irrigation is mainly done using fixed, hand shift, lateral move and travelling sprinkler systems. It was estimated that the annual value of irrigated agriculture in the region could be as much as $484 million (NSW Agriculture, 2002). The irrigators in the HNC come from very diverse ethnic and social backgrounds and many of them are the people are from Non English Speaking Background (NESB). Majority of vegetable growers (over 80%) in the HNC are from NESB.
Data Collection and Analysis
Data for this study were collected over a period of three months by one-to-one interviews with selected irrigators in the HNC, and the interviews covered a range of issues related to irrigation scheduling. The irrigators selected represent a significant proportion of the irrigated area of the HNC and includes all the main irrigated crops in the catchment. A total of 30 farmers were selected randomly from a database of New South Wales Agriculture’s Water Wise on the Farm program. Majority of these farmers have completed the 4-day ‘Introduction to Irrigation Management Course (IIMC)’ with NSW Agriculture. Main crops irrigated by the farmers included vegetables, fruit trees, turf, nursery plants, olive trees and cut flowers. Table 1 shows distribution of these farmers for different crops. Six out of seven vegetable growers, 3 out of 4 fruit growers, 3 out of 4 turf growers, all the dairy farmers, nursery owners, olive growers, cut-flower producers and lucerne growers attended WaterWise on the Farm and / or other training course in irrigation water management.
Table 1. Number of farmers included in the study with their main irrigated crops.
Main irrigated crop |
Number of farmers included in the study |
Vegetable |
7 |
Fruit |
4 |
Turf |
4 |
Dairy |
5 |
Nursery |
4 |
Olives |
4 |
Cut-flowers |
2 |
Total |
30 |
Informal interviews, lasting up to two hours, were conducted with these irrigators. The questions asked to them included both general and specific to gain an overview of their irrigation practice and understand irrigation scheduling issues specific to individual farmers. Firstly, some general information about their farming enterprise such as type of crop irrigated, soil type, source of irrigation water and type of irrigation system used was obtained. Specific questions related to irrigation scheduling asked included - how do they make their scheduling decisions, how do they incorporate their experiential knowledge in scheduling decisions, do they use any scheduling tools such as tensiometers to help in their decision making, do they know how much water they are applying in any particular irrigation event, and is there a scope to improve their scheduling practice and save water? They were also asked about their views on the influence of weather and other farm activities on scheduling decisions they make routinely. Further, farmers were asked to nominate some key issues that need to be addressed by research and advisory bodies for improving their scheduling practice.
Responses from the farmers were collated and analysed under different questions to develop insights into the current state of irrigation scheduling in the study area. The analysis also resulted in emerging themes and key issues that need to be addressed for improving scheduling practices in the HNC.
Results
How do farmers in different industries schedule their irrigations?
Out of the seven vegetable growers interviewed, six schedule irrigation by looking at the plants. They turn on their sprinklers if the plants appear to be bit water stressed. The number of irrigations and the amount of irrigation water they apply change with soil type, weather, crop, and stage of crop growth. Four irrigators schedule irrigation based on their judgement of soil moisture mainly by “Gut & Feel” method. However, they advance the irrigation schedule if the leaves are showing a sign of plant wilting. The flower producers also schedule irrigation based on their own judgement of plant water need, soil type, soil dryness, age of flowering plants and weather prediction for the next few days. Similar to vegetable growers and flower producers, nursery owners also schedule irrigation based on their own judgement and experience and by looking at plants for any sign of wilting and soil dryness.
All four fruit growers included in the study were scheduling their irrigation by looking at the prevailing weather, soils and future weather prediction. One grower mentioned that he tends to schedule irrigation based on weather situation, season of the year, and short-term weather forecasts from Internet and TV. He also confirms his irrigation scheduling decision by walking across the field for any sign of water stress in fruit trees and weeds as shown by curling of leaves. However, the other fruit grower mentioned that he often checks his tensiometers as a first step, and he then considers the weather forecast for the next few days for making irrigation scheduling decisions. However, this strategy sometimes does not work for him. Another grower mentioned that he schedules irrigation based on his visual observations and intuition, but sometimes he cross checks the scheduling decision by digging a bit of soil for moisture level. One fruit grower said that his scheduling decision is generally dictated by weather conditions (he attempts to apply irrigation when the weather is too hot) and whether he is free from his other work. He is also very keen to have irrigation and drainage management plan developed for his farm and replace the old irrigation system with a new drip irrigation system.
In the case of turf growers, market forces tend to drive the irrigation scheduling. They usually decide to irrigate based on their own judgement and experience, i.e., by looking at the grass. They advance or delay the irrigation based on the prevailing selling price for turf grass in the market. They apply more frequent irrigations to young grass than the older one. Irrigation is also applied on the following day to the freshly cut turf grass. One turf grower has developed his own irrigation scheduling program. He says, “When I do not see dew drops on the grass under my gum tree in the paddock, I check my turf paddocks for watering. This is first indication to me that my turf grass needs water”. Another method he uses for irrigation scheduling decision is: “When ants near the gateway start making their nest, it means it will rain soon and I should delay irrigation to my paddocks.”
The dairy farmers schedule irrigation on a regular interval to cover the bigger area. The inadequate infrastructure is often perceived to be an insurmountable barrier to altering their timing away from a set rotation and set time for each section. Their scheduling decision is often based on weather forecasts in the near future and prevailing temperature and other climatic factors, plant appearance, soil type and soil dryness. Irrigation scheduling is also adjusted to some extent with grazing and fertilisation schedules on their farms. They also delay irrigation when cattle are grazing in the paddock.
The Olive industry in the HNC is relatively new and is picking up quite well. The olive growers started it as a hobby. Since these people do not have much experience of agriculture in general and irrigation water management in particular, they are very keen to take a technical advice. One farmer says: “For irrigation scheduling, I normally take a soil sample with a probe and feel the soil moisture. I irrigate normally twice a week in very hot summer days and only once a week otherwise. I obtain pan evaporation data from a nearby weather station and refill the deficit water in the rootzone through irrigation. The other grower says: “Initially I used to irrigate for half an hour every week to wet the plant rootzone in summer. Then I learnt that olives are not dormant in winter and need water both in summer and winter. Now I irrigate for 3-4 hours every 3 weeks or so depending on plant appearance for water stress, soils and weather”.
Do irrigators in HNC use any tools for the scheduling?
Majority of the turf, dairy, lucerne, vegetable and nursery growers have not used any soil moisture monitoring tool to schedule irrigation in the past. The different constraints include too costly system, too much time consuming process, too complicated and we do not know which system would best suit our needs. Some vegetable growers indicated that their own judgement for irrigation scheduling was very close to the reading, and this is one of the reasons they have never bothered to install a soil moisture monitoring system. A common response from these growers was: ‘we already have several years of experience in farming and scheduling and any refinement in our scheduling practice will result in extra cost and time’. Nursery owners grow seedlings in pots and think that they cannot install soil moisture monitoring systems in the pots, but prefer to use data from a weather station showing the daily evaporation rates. The olive growers have also not yet installed any soil moisture monitoring system, however, all of them are looking for an advice to decide which moisture monitoring system is best suited to their needs.
Table 2. Irrigation scheduling methods/tools currently used by irrigators in the HNC*.
Crop |
No. of farmers using the irrigation scheduling method/tool | |||||
Plant appearance |
Intuition |
G-bugs |
Tensiometers |
Weather prediction |
Fixed interval irrigation or other method | |
Vegetable |
6 |
4 |
0 |
0 |
2 |
0 |
Fruit |
1 |
2 |
1 |
1 |
1 |
0 |
Turf |
3 |
0 |
0 |
0 |
0 |
1 |
Dairy |
1 |
2 |
0 |
0 |
0 |
2 |
Nursery |
4 |
1 |
0 |
0 |
0 |
0 |
Olives |
0 |
2 |
0 |
0 |
0 |
2 |
Cut-flowers |
2 |
2 |
0 |
0 |
2 |
0 |
Total |
17 |
13 |
1 |
1 |
5 |
5 |
If total number of irrigators using different methods for irrigation scheduling is more than the total number of farmers surveyed, it means some farmers are using more than one irrigation scheduling method.
The most non-confident group in plant look and feel method was olive growers who do not have much background in farming. These growers are mostly hobby farmers in the HNC, and they are looking to install an appropriate soil moisture monitoring system as per the advice given by consultants or utilising their own experience and interaction with other growers. Dairy farmers and turf growers may want to follow irrigation scheduling if the capacity of their irrigation system can cope with schedules based on soil moisture status and plant water requirements. They cannot wait till all their paddocks reach the appropriate moisture level to schedule irrigation. Doing this will put their last paddocks under water stress and will lead to a decline in pasture yield and quality.
Two of the four fruit growers have a soil moisture monitoring system in place and they have found it quite useful in making irrigation scheduling decision. Another farmer is waiting for advice from a consultant preparing their Irrigation and Drainage Management Plan (IDMP) as what would be the best soil moisture monitoring system suitable for their soils and trees. The fourth farmer said that I do not need a soil moisture monitoring system at the moment as I am going quite well with my own judgement of looking at the tree appearance, weeds, soils and weather in the next few days.
Are irrigators in HNC interested in installing a soil moisture monitoring system?
About one-third of total number irrigators included in this study showed interest in installing some type of soil moisture monitoring system to reconfirm whether their scheduling decision based on visual observations and experiential knowledge is appropriate (Table 3), but they were not sure of which monitoring system would be best suited to their soils and crops, e.g. shallow rooted vegetable growers, flower producers, dairy farmers. About a quarter of the irrigators are interested to connect the soil moisture sensors to an automatic system for applying the exact amount of water to the crop when the sensor reading has reached a critical soil moisture level. None of the vegetable growers showed an interest to install any plant, soil and weather monitoring system in the future for irrigation scheduling. These growers are running their family farms and have long-term working experience on their farms. They said that they have a reasonable understanding of their soils, the water requirement of crop they grow and they keep a good eye on weather predictions. It should be noted that the irrigators represented in Table 3 are probably not representative of the all irrigators in the HNC. This is because most of them have done Water Wise on the Farm training course that made them to think about cross-checking their scheduling decision with an instrument.
One of the vegetable growers even said, “Someone from one of the research organisations did some experiments on my property to schedule irrigation using some soil moisture monitoring system. My own judgement was very close to what his monitoring system was telling. So I never bothered of to install one when my own judgement is quite good”. Another grower said, “I bought couple of tensiometers, but I do not think they can help me to make a better irrigation scheduling decision as I grow normally shallow rooted crops and I cannot install tensiometers at too shallow depth”.
Similarly, no nursery owner showed interest in installing a soil moisture monitoring system, as they do not know which is the best system for checking the moisture status of the growing media in the pots. On the other hand, two of the cut-flower growers surveyed showed interest in installing the soil moisture monitoring system, although they are quite experienced (with over 20 years of experience in growing flowers) in their own field.
Table 3. Farmers interested in installing a monitoring system for irrigation scheduling in the HNC.
Industry |
Farms surveyed (No) |
Interested in a monitoring for IS |
Interested in automation |
Vegetable |
7 |
0 |
0 |
Fruit |
4 |
3 |
1 |
Turf |
4 |
2 |
0 |
Dairy |
5 |
1 |
0 |
Nursery |
4 |
0 |
1 |
Olives |
4 |
3 |
3 |
Cut-flowers |
2 |
2 |
2 |
Total |
30 |
11 |
7 |
Three out of four fruit growers are interested to install some soil moisture monitoring system on their properties. This is also true in the case of olive growers. These farmers have limited amount of water available to water the fruit trees. They are interested to install a monitoring system to make the best use of their limited water and obtain a better crop. A fruit growers and a olive grower among the irrigators interviewed were interested in a system which can automatically release water to the trees when the sensor reading reaches at a critical level. They are growing high value crops and do not want to take a chance to loose their crops due to water stress at a critical stage of crop growth.
Two out four turf farmers showed interest in installing some soil moisture monitoring system on their properties (Table 3). Only one dairy farmer showed interest in installing some soil moisture monitoring system for irrigation scheduling. He said, “ I do not know what is best system for dairy pasture paddocks, but if you want to do any trials on our place and show me which system can give me better returns for my investment and water, I can go for it”.
Discussion
Most irrigators in the HNC schedule irrigation based on their own judgement and experience. Fruit growers did not practise irrigation scheduling since they could not see any benefit in it. They take soil physical appearance, plant look, crop type and age and weather prediction into consideration for making irrigation scheduling decisions. They do not go for actual determination of the soil moisture in the rooting zone or any other estimation of plant water requirement. They are probably over irrigating in some instances as they do not know or take into account the depth of rootzone that varies with stage of crop growth. Also, they do not know how long they need to keep their irrigation system operating to refill the rootzone to field capacity. In some instances they could also be stressing plants for water if they solely rely on dryness of surface soil for the scheduling decision. For example, a small amount of rain (e.g., 10-20 mm) could make soil appear moist on the surface but it may be relatively dry in the most part of the rootzone. If the scheduling is solely based on plant water stress, by the time the stress in plants is noticed, plant may have already suffered some damage due to reduced plant metabolism and nutrient supply. This can adversely affect the plant growth, leaf area development and crop quality and yield.
In the present study, a few irrigators asserted that there was no need for paddock water use monitoring, and even one of them said that it was “a waste of time”, while a couple of others did not want to know about it if it involves extra work. One irrigator also said that the monitoring was of no use to him as it did not address irrigator behaviour and needs; while another was concerned that individual’s water use details might be seen by regulatory authorities and could affect their water allocations. A study by Humphreys et al. (1998) in the Murray-Darling Basin also found that majority of the farmers in the area do not see any sense in water use monitoring.
Robbins (1992) found that the most of the horticultural growers surveyed in NSW had a reasonable idea of the soil, weather and crop interactions but many did not understand the concept of water holding capacity of different soils and how it affects the frequency of watering. Further, irrigators often consider irrigation scheduling a theoretical topic that is appropriate for technical and highly qualified people to use. They think that the biggest challenge may still be to develop scheduling methods that are readily transferable and adopted by irrigation community.
Estimates by Yiasoumi (2003) suggest potential water savings of 18 GL a year if improvements are made to existing spray irrigation systems used in the HNC and other catchments supplying water to the SMA. Further savings in water consumption can be achieved through improving irrigation scheduling practices of the farmers. Irrigation scheduling is defined as applying the right amount of water at the right time when the plant needs it. So far, in the farming community, irrigation scheduling has always been given a low priority for training needs. Also, the uptake of available irrigation scheduling technology by farmers has been poor. The reasons for this low uptake are complex, but it is often due to the technology being too complex for the farmers to implement in the field, or in some instances the technology simply does not work in field situations.
Market forces, i.e., what the consumer wants, drive many irrigators in a majority of industries. This dictates priorities given to certain tasks on the farm; one of many in the production system is irrigation. Irrigation is seen in many growers worldview as just one input in the production system. Too often, messages to irrigators on the benefits of irrigation scheduling are too broad, and therefore such messages are not considered important enough to allocate time in their day-to-day farming operations. This is supported by Burt (1996) who states that irrigation scheduling programmes must be strong enough to withstand physical and human uncertainties growers are faced with. We as extension and change agents must better understand these uncertainties for the industries we are working with. In other words, how can we improve the efficiency of the overall irrigation system to maximise profitability and environmental performance of the farming business. The present study has identified that 83% of all irrigators would like to improve the performance of their current irrigation system. The challenge is before us to provide better extension programs that meet irrigator needs. As observed in this study, a number of growers are constrained by their farm management operations when scheduling irrigation on their farms. The question is, how do we make irrigation scheduling a higher priority in the farming operations of all industries?
This study indicates that there is a need to address the key irrigation scheduling issues more effectively for each industry in the HNC. Often, the partnerships for building trust and integrated teamwork involving farmers, researchers and advisory people has not occurred. Many reasons for this include poor planning, lack of funds, lack of consultation, and the use of broad brushed approach to the benefits of irrigation scheduling. Poor delivery of irrigation training, lack of practical methods, and growers being cautious of government’s regulatory policies are all contributing factors. For any successful irrigation scheduling, the trust building with farmer communities and understand their needs is of paramount importance. Many growers in the HNC do not have the capacity, confidence and skills to adopt complex technology. We certainly need to simplify our scheduling options for some industries, particularly for the vegetable, turf, dairy, and cut flower industries. This includes identifying fewer options in plain English so that growers can make a better-informed choice or decision for irrigation scheduling.
We need different strategies and approaches for farmers who still irrigate haphazardly, and are over watering. Greater research is needed as to what is the best method in the HNC. Plunkett (1996) found the most effective method for identifying poor irrigation practice was with a simple device that showed visually to the irrigator that over-watering had occurred. Similar experience is reflected in the work undertaken by Stirzaker and Wilkie, (2002). Farmers learn by doing, and in many instances with growers of NESB, a method that illustrates the problem with their current irrigation practices would meet the needs of many growers.
How do we inspire industries to develop their own irrigation management programs to address these issues? How do we create ownership of projects by the community? These are some of the questions that need to be addressed. Future Government regulations for water will drive changes in irrigation scheduling as will the cost of water in some industries, particularly those using town or potable water supplies. The extension role of organisations such as NSW Agriculture must accept that cultural change is the biggest barrier to adoption of complex systems. Facilitating the capacity of industries must be coupled with the development of research and technical advice that is targeted to individual group of irrigators and at the same time relevant to their needs.
Clearly, government extension programs such as Water Wise on the Farm are raising awareness of irrigation scheduling in the context of the overall irrigation management system. Plunkett, (2003) documents examples of behavioural change and technological change in the NSW turf industry. This change occurred as a result of the growers improving the way they think about irrigation. Many trainees are questioning whether there is a better way to irrigate than the way previous generations did it! However, they are not, in many cases changing practice on ground, even with financial assistance measures. Course evaluations have shown that behavioural change is occurring amongst 90% of all trainees. Yet the adoption of scientific irrigation scheduling technology is low, even with financial assistance. We need new approaches that address these issues.
The results of this study show that farmers believe they are scheduling irrigation in their own right. For example, when a grower is asked whether they schedule their irrigations, they obviously say yes based on their own experience, weather conditions or when the crop needs it. As Table 3 suggests, this is not to the level that government, water authorities or regulators perceive as formal or scientific best practice irrigation scheduling i.e., with the aid of a tool or device. Too much emphasis is placed on the technology, not how it interrelates with the decision-making processes of the farmer. The key point here is that scientists think differently to farmers. Stirzaker (2002) concludes that scientists portray irrigation scheduling as an exercise in accuracy – the idea that there is a defined point between when irrigation should occur and when to cease irrigation. In reality, this does not occur due to many other pressures on the farm. More importantly, the question is the value of the information to the farmer in reducing uncertainty and improving profitability. Greater work with growers is needed to determine the cultural and social issues that inform their decision making process.
The cost of irrigation scheduling equipment for many growers is to high, particularly for crops that are currently receiving low returns such as some vegetable industries. Tollefson and Wahab (1996) summarise this argument by stating that without economic or social incentives for scientific scheduling, adoption of technical and real time scheduling procedures has been slow or non-existent. As Table 2 suggests, only 11 are interested in some form of irrigation scheduling, apart from their current practice. However, more importantly many said they would be interested if they knew which methods were applicable relevant and cost effective.
This study indicates that there is a paradox between giving the irrigators enough information, and convincing them that change is worthwhile. Casey (2003) discusses perceptions of clients, and how they value a service. A ‘Promotion Pyramid’ is used to identify where client responses fit. There are four components of the pyramid: unaware, aware, convinced and action takers. Evaluation of the WaterWise program is showing that 90% of participants have made behavioural change, and want to improve their irrigation system. We are achieving the goal of making them from unaware to aware and in some instances from aware to be convinced. So far we have not been as effective as change agents in convincing people to act. There influences and reasons for that as mentioned earlier include understanding of grower’s background, policy and cultural issues, current water reforms, technology for irrigation scheduling being often too expensive and poor backup advice.
With the NESB community, we must adapt or tailor our approaches and messages to more visual ways of learning. Stirzaker & Wilkins, (2002) and Plunkett (1996) have shown how visual ways of irrigation scheduling can change attitudes and behaviour, with minimal cost and inspiration needed for clients to act. These approaches should be explored further with growers of NESB and other industries.
In summary, a critical issue in the whole debate about best practice for irrigation scheduling is perception. The way in which a farmer sees irrigation scheduling in relation to their farming business, and what a researcher or extension officer views through their eyes as best practice. Extension officers and scientists are often too focussed on getting the exact science right, instead of understanding practical and cost effective measures that affect and guide decision making processes of farmers. Stirzaker & Wilkins (2002) argue that it is not so much about irrigation scheduling being precisely right, it is more important not to be consistently wrong! Until the worldviews of the extension officer, researchers and the farmer are more closely aligned, poor adoption of irrigation scheduling methods will continue to occur.
Conclusions
This study has highlighted the key challenges facing irrigators in the HNC for better irrigation scheduling practices. A significant number of irrigators do not use any soil moisture monitoring tool to schedule irrigation although they appreciate need to save water. A number of factors that affect irrigation scheduling in the area include the limited understanding of soil-water-plant relationship, cost of monitoring soil-moisture and accommodating irrigation activity with other farm tasks. In most cases, irrigators’ own experience of irrigation practice played an important role as to the irrigation scheduling decision. The practice of irrigation scheduling and interest of irrigators to adopt improved scheduling technology varied considerably with the type of industry. There is a need to develop irrigation scheduling approach that is cost effective, simple and easy to implement. Researchers and extension people need to recognise that irrigation scheduling does not need to be an exact science, and there are inherent limitations and constraints that irrigators are faced with in implementing irrigation scheduling in real world situations.
References
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