New research shows some over-enthusiastic organic farmers may be contributing to environmental problems. Australian agricultural scientist Graeme Stevenson says some are using too much compost and over-fertilisation could leach nutrients and release extra carbon into the atmosphere. S tevenson, who’s been working on behalf of the Organic Coalition of Tasmania to collate information he’s gathered from organic farms over the past couple of decades, says the research gives farmers a chance to clean up their act. “We pride ourselves as an industry on looking after the environment,” he tells the Broadcasting Corporation.
“This is a bit of an embarrassment – well great, let’s face it. Let’s warn our growers and build this awareness into our certification system. We’ve always been aware of avoiding over-composting as a general rule, but this is much more specific.” tevenson is involved in the long-term benchmarking of the available soil nutrient status on a range of organic enterprises. He is aiming for observations over at least 30 years on each property, with data collected at least every fifth year. |fw
New apple cultivar: blushing beats browning
Instead of browning, Australia’s Western Dawn apple stays a pale pink for hours. Alan Harman reports.
Australian plant breeders have developed an apple that doesn’t turn brown when cut, but stays a pale pink for several hours. he Western Dawn, which will be sold under the name Enchanted, was developed through conventional breeding techniques, not genetic modification (GM). he Western Australia Department of Agriculture and Food developed the apple as part of the Australian national apple-breeding programme.
“Enchanted apples’ resistance to oxidation makes them much more useful and attractive,” Western Australia agriculture minister Kim Chance told the Broadcasting Corporation. “They’re likely to be very popular for platters and lunch boxes, and for fresh juicing, where they retain an attractive pink blush and fresh, light flavour.” C hance says because the apple was produced without GM, it can be marketed around the world. The new variety will initially only be available in Western Australia. There are plans to expand sales throughout Australia, then internationally. |fw
Electric fences don’t scare elephants
Kenyan researcher John Kioko has found there’s more to keeping elephants out of crops than just electrifying fences. Roelof Bezuidenhout reports.
Game managers, particularly on private reserves, tend to think electric fences are all it takes to keep in elephants. But, argues John Kioko of the School for Field Studies at the Centre for Wildlife Management, Nairobi, the factors that control these animals aren’t fully understood.
Writing in the SA Journal of Wildlife Research, Kioko says studies at two Kenyan game parks showed a current doesn’t stop elephants breaking fences. “Our research suggests the location of fences in relation to landscape factors, maintenance of effective non-electrified fences and proximity of fences to areas of high elephant concentration, all play a role in the likelihood of elephants raiding crops,” Kioko warns. The studies show elephants learned to get through electric fencing by using their tusks to break the wires or pushing down the poles. It’s speculated that low or variable voltage increases fence breaking.
At Mwea, Kenya, a voltage maintained at 5kV has been a successful deterrent. But, advises Kioko, fences located near woodlands which provide cover for crop raids, or in areas with high elephant densities, should be intensely managed or reinforced. “Where elephant pressure is low, good non-electrified barriers may be equally effective deterrents to problem elephants,” he says. Kioko notes that human-elephant conflict is widespread in most elephant range areas. In Kenya, 130 elephants were killed between 1990 and 1993, while elephants killed 108 people there in the same period. E-mail John Kioko at [email protected].
