A TOUR of Tony and Alison Smith's 80ha property Bouverie was the highlight of the Green Skills field day at Denbarker. Their original much larger farm was reduced to its present size in 1974. In 1968 they planted their first 2ha (5 acres) of wine grapes. The planting led in 1974 to the establishment of Plantagenet Wines in Mt Barker. The now mixed farm is run with the assistance of a fulltime employee Brian Gee.
"All of the ten enterprises we have here must fit into the environment," Mr Smith said. One of which is we re-circulate all the water we harvest while moving it from dam to dam. There's a soil water spring system installed for our trout and marron."
Nikki Poulish, agriculture department development officer, Mt Barker, stated the water is 90pc fresh, the remainder salt water. Contour drains feed water to dams holding 70,000 cubic metres, and ponds of 12,000 cubic metres of fresh water. There are 8000 cubic metres of dual-purpose dams of moderate salt level water and 3500 cubic metres of higher-level salted pondage. A further 8000 cubic metres salt water dams are planned for 2004 and built to ensure the water in them is not contaminated by acid sulphate soils. All available sources (including roads) supply water to dams via 20m wide contour drains built to a clay depth of 1-1.5m. The harvesting system has been constructed to divert salt-water flow past the fresh water dams at periods of reduced flow levels containing a high salt content. Water is run through settling ponds before re-entering the main dam and later used to irrigate the vineyard. In 2002 six trout tanks (two of fresh water) were built and two fresh water-purging tanks were built for marron. All these are in a newly built processing shed.
Ms Poulish said the salt-water ponds (1000mS) have recorded the fastest trout growth rates of the property, while being fed only thrice weekly. She said the salt-water ponds were initially stocked at 50 fish per pond, then doubled to 100 and doubled again to 200 head per pond. But when water temperature reached 22deg C mass deaths occurred. Trout are sold when they reach 400-700g weight. Mr Smith estimates his trout enterprise will break even with running costs during 2004 and return on capital will be much slower. The trout require 700hrs of labour annually while providing 100kgs sold for $8-10/kg.
Five ponds have been built on the property for breeding marron. There are nine marron growing out ponds and five dual purpose ponds that contain both male and female marron and trout. Yabbies are stopped from entering marrons dams.
Forestry is another venture: trees being planted for general purpose timber, furniture timber, turning timber, and for biodiversity, beautification and revegetation. Greg Duke, Green Skills co-ordinator has supervised the planting of 20ha of trees between 2000 and 2003. They include karri, jarrah, blackbutt, bottlebrush and others, including Tasmanian blue gum and southern mahogany for their timber value and Salt River sheok and flat topped yate for furniture.
Green Skills specialist tree pruner Albert Adams spoke and demonstrated the correct and incorrect method of pruning fast growing trees. "Poor pruning can cause infections and/or knots which greatly devalue the main stem or trunk wood - the very reason you're growing the tree," he warned. Pruning and thinning is done by Green Skills personnel. Mr Smith said the managing of his tree lots is as high as $4500 a year.