There are several types of pumps that can be used in a bore – a piston pump, a helical rotor pump, a jet pump, and turbine pump. Choosing the right bore pump will depend on water quality, the diameter and depth of the bore, bore capacity (litres per hour or standing water level), pump purpose (direct irrigation or filling a tank), and the level of investment. Choosing the right bore pump can help to reduce damage to the pumping equipment and ensure many years of service.
Timbara Nursery at Thornlands on Brisbane’s Bayside was the venue for a very successful ‘Farm Management System Field Day’ presentation conducted recently. Approximately 30 participants attended the June on-farm presentation to observe the outcome of a total irrigation retrofit that was recently implemented to upgrade the irrigation system to industry best management practice (BMP). The Field Day presentation provided an ideal opportunity for nursery owners and managers to witness personally the results of this irrigation upgrade and also an opportunity to discuss with the nursery owners all financial and water saving benefits.
Good irrigation water quality is a keystone to producing quality nursery stock, and most water supplies require some form of treatment to make them suitable for nursery use. Water can be treated for four types of contaminates – particulate matter, pH, salts and pathogens. The following article discusses how to test for the effectiveness of treatments applied to kill or remove pathogens.
Record keeping must just be one of the most disliked tasks a nursery owner or manager must undertake, but it really is one of the most important. Quality Assurance (QA) and Best Management Practice (BMP) programs require extensive record keeping to ensure the business organisation stays on track and can quickly identify emerging problems.
Your irrigation pump stops pumping. What's your first reaction? Reach for the phone and call your friendly local irrigation repairer? Sometimes a systematic approach to diagnosing developing or crisis problems can pay dividends in minimising down time. The following is a guide identifying common pumping problems. You may even be able to fix the problem without the need to contact a professional.
Irrigation pumps are the heart of a nursery irrigation system. Pumps can be either rotodynamic e.g. centrifugal pumps, or positive displacement e.g. helical-rotor pumps. Most nursery irrigation systems require high efficiency and high pressures (head) which usually limits pumps suitable to these systems to rotodynamic pumps, but in situations where pump discharges are less than 2 litres per second, positive displacement pumps may be used e.g. misting systems.
The measurement of dam volumes is an essential part of efficient water management. Firstly, knowledge of how much water a dam holds is needed to ensure that there are sufficient quantities available for the production area available through the driest times. This information should form part of the data collected when determining the size of production areas. Secondly, an accurate measurement of the volume remaining as dam levels fall allows management decisions to be made about where water is best used in the business e.g. reducing irrigation on mother stock areas. Thirdly, if the dam is used to collect runoff water to minimise impacts from nutrient run off, or catching the first 25mm of runoff from the site to retain the majority of pollutants, the maximum height that the dam must be held at needs be known.
Capturing the irrigation and surface run-off in a nursery or greenhouse situation is one method of a improving the efficiency of water and nutrient use. However there are a number of critical considerations that need to be addressed in any situation where recycled water is to be used. A primary question should be: is there sufficient room for the construction of an adequately sized catchment pond that has the potential to supply sufficient volume back to the system to supply production requirements? If the answer to this is yes, then the next primary consideration must be that of water quality.
The single greatest contribution production nurseries can make towards water use efficiency and reducing their environmental impact is to engage in the strategy of collecting and recycling or reusing their irrigation waste water.
The management of water intended for nursery irrigation will have a direct impact on plant quality, plant growth and the bottom line of a business. Overall design, together with the management of a nursery irrigation system, will determine irrigation system performance. System design must be cost effective, storing sufficient and sustainable volumes of water for irrigation and applying this water to the crop to meet the requirements of the site’s nursery production.
Nursery expansion, new installation, unreliability or controller breakdown, if you are in the market for a new irrigation controller there are an increasing array of options available that should be investigated. The electronics industry has progressed at an amazing pace in recent years and the evolution of irrigation controllers has continued with options now available that were not thought possible only a few years ago. One system that is becoming increasingly popular because of versatility and decreasing costs is the two-wire irrigation control system.
Selecting appropriate filtration equipment for an irrigation system can be a complex process. Information on water quality available and the water quality required has to be assessed before the appropriate options can be considered. In making these decisions it is imperative that an irrigation specialist is employed to ensure the filtration system performs efficiently. The following table gives an overview of different filtration types used in nursery irrigation. For more information refer to “Managing Water in Plant Nurseries”.
A survey of production nurseries that participated in WaterWork workshops found that information on average water use, water cost, pumping cost, maintenance cost, and hand watering labour cost was not known. A similar lack of data has also been found during the course of the RWUE project. The benefit of a system audit for production nurseries is that it identifies maintenance items that will reduce system downtime and will help to improve productivity and profitability. Conducting a system analysis demonstrates to regulatory authorities that a responsible approach is being taken to water management, and impacts to the environment are being minimised. As an industry, it is imperative that information gained from irrigation system audits is readily available, so that nurseries have continued access to water.
There are a number of ways in which efficient irrigation layouts save water. Matching the Mean Application Rate (MAR) to the absorption rate of the growing media can help to decrease water use by minimising the water lost through leaching. If water is applied at a rate that exceeds the absorption rate of the growing media, the excess water can’t be taken up, and flows through the growing media and out of the container. The following comparison gives an example of water savings that are possible when the MAR is matched to the growing media absorption rate.
Onsite testing provides an easy way of determining water quality, so that timely corrections can be made. A keystone to achieving this is the suitability of the testing equipment used. Onsite testing is a much cheaper option overall than laboratory testing and, in some cases, is the only practical way of testing for some parameters e.g. chlorine testing for water treatment.
Significant amounts of nutrients can leach from growing media during irrigation. A survey of nurseries has shown that the leaching of nutrients such as nitrogen, phosphorous, iron and manganese can exceed water quality guidelines, with nutrient losses being particularly high in the weeks just after potting. Nutrient losses can be 60% higher in summer due to more frequent and longer irrigations.