WHILE most farmers are wishing for rain, Gary Peacock is generally cursing an extra 5mm in his rain gauge.
He farms 1730ha at Bibby Springs, west of Badgingarra and 25km from the Cervantes coast.
With a shallow water table and annual rainfall of 585mm ‹ which falls predominantly in winter ‹ cropping has been out of the question.
Gary runs 7000 sheep and over the past five years has planted 160ha of subtropical perennial grasses to beat rising water tables and provide green feed over the summer.
The principal soil type is sand over clay and the property is flat.
In winter, inundation is a problem and some areas have become scalded where water lies for extended periods.
"Once bare, it is difficult to establish anything on these areas," Gary said.
He looked to raised beds to get around the problem of plant establishment and growth.
"Raised beds would provide an engineered rootzone out of the waterlogged conditions which would enable rainfall to leach accumulated salts out of the soil profile and provide an aerobic growing environment," he said.
Gary approached Agriculture Department researcher Greg Hamilton with the idea of establishing perennial grasses on waterlogged and salt affected land.
With the backing of the Evergreen Group, Greg and Gary secured funding from the Land, Water and Wool project Sustainable Grazing on Saline Land last year.
The area was surveyed using differential global positioning satellite technology, producing a contour map, essential for Greg's design of the beds and drainage system.
Over the 1.6km long and 75ha site, there was just a 2m fall and an EM38 reading highlighted hotspots where the salinity was up to 200mS/m.
Drains were installed in May and the beds formed the following month by Agriculture Department technician, Cliff Spann, using a Gessner three point linkage bed former and 7700 front wheel assist John Deere tractor.
Three full and two half beds are formed in one pass, the beds each 1.83m in width.
Rainfall during May and June was average (188mm) and 25ha of Moondyne barley and 25ha of annual pasture was sown on the beds in July with the Department¹s front-mounted air seeder box and three point linkage seeding bar, with DBS closers and press wheels.
The 7.3m bar sows four beds in one pass.
A further 25ha of subtropical perennial grasses will be sown on the beds next month.
More than 250mm of rain has fallen since sowing, which is not unusual in the district, and Gary said the results have been more than encouraging.
"Germination has been good and ryegrass and clover is now growing on sites that were formerly scalded and grew only barley grass," he said.
His machinery modifications for raised bed farming have been minor.
The standard 23.1.34 rear tractor tyres will be replaced with a narrower 18.1.34 tyre and super single tyres and rims will be needed on the rear of the spreader truck with a total changeover cost of less than $2000.
"The 24m boomspray fits the bed layout perfectly and the only real adjustment has been getting used to working up and back, rather than round and round," he said.
³With raised beds, tramlining comes automatically but without the cost of electronic guidance."