Innovative Irrigation: It was necessary for a meat packaging company to improve wastewater quality and prevent ground-water pollution at its Oringi plant in New Zealand. At the same time the company was seeking a cheaper, more efficient alternative to transporting coal for the boilers over 500 kilometres from the mine. Richmond Limited and consulting engineers, Royds Garden, implemented a program to grow firewood gum trees using treated irrigation water from the plant. An existing race and border dyke system was converted to flood irrigation using 1800 metres of Iplex BLUE LINE DNl60 PE80B which had been drilled with holes. PE80B offered a number of advantages for the project including excellent resistance to attack from chemicals and micro organisms; flexibility and light weight which facilitated installation by hand and most importantly, strength which enabled the pipe to withstand being driven over by log harvesting vehicles even when only partially buried.

The irrigation system carries wastewater from an anaerobic pond to irrigate the crop of gum trees. The treatment process ensures freedom from poliution while the piped underground transmission ensures there is no release of contaminants directly into the air. The trees take up and convert remaining materials in the treated effluent providing a highly efficient, environmentally sound recycling system. The irrigated crop of firewood gums will be harvested on a 3-5 year cycle to provide an alternative fuel source to coal for the company's boilers.

Wineries in Australia are installing Dripline Irrigation. One of the largestsuch projects was in the NSW Riverina district on a 648 hectare property owned by Riverina Wines and irrigated by 1700km of Ecodrip dripline and 60km of PVC pipe from Vinidex. Two 375mm PN6 PVC mainlines were installed at the same time as the electric cable for automation of the system. All pipe routes were first surveyed and pegged, including the location of submain off-takes. Some 600m of 375mm pipe were installed per day in a 1200mm trench, while two separate gangs put the 200mm and 150mm sub-mains pipe in place ready for installation.

At the McGuigan vineyards in the Hunter Valley, drip irrigation is more than an efficient means of irrigation, it is also a vital weapon in the battle against the local threat of downy mildew. The high humidity of the coastal climate creates perfect conditions for the growth of the fungus unless the leaves of the vines are kept dry. This rules out overhead sprinklers but makes driplines the perfect irrigation solution because the water droplets go directly into the ground, not on the foliage. McGuigan's Cowra vineyard is a former wheat farm in flat tableland country with ample frost and cool weather, ideal for viticulture. A dual water supply on the property draws 438 megalitres a year under licence from the Lachlan River, while a bore supplies a further 90 cubic metres an hour. With both the river and bore pumps working, the Ecodrip system can irrigate 40 hectares at once. More than 130 kilometres of Ecodrip 35 dripline delivers water to some 87,500 Chardonnay vines and a trial block of Italian San Giovese red grapes.

Reduced water flow and night irrigation mean savings in energy, while accurate application of fertilizers and agrochemical provides a choice of either lower chemical volumes or greater yields. Some of the hidden benefits of low volume drip irrigation are fewer weeds, better control of soil stress, reduction in ground compaction and control of harvest timing. PVC pipe was selected for its ease of installation, proven performance and minimum maintenance. Ecodrip was chosen for its economical, reliable delivery of water and chemicals. Developed by Naan of Israel, Ecodrip complements the range of Naan sprinklers supplied by Vinidex as well as filters, valves and a wide range of PVC and polyethylene pipes for mains and submains.