Ground Cover North : Ground Cover 064 September-October 2006 - North
With shallow loam over limestone soils, the Kakoschke family is experimenting with a rock saw and rock profiler to increase the soil depth -- with good results BY EMMA LEONARD n ‘Don’t dabble – do your research’: this is the maxim at the heart of the Kakoschke family’s farm management strategy for their mixed enterprise on central Yorke Peninsula in South Australia. It is a strategy they say helps them continue to meet the challenges of farming shallow but fertile soils in a district that receives 400 millimetres of winter-dominant rainfall a year. The Kakoschkes – Rex and Helen, with sons Evan and Peter and daughter-in-law Lauren – farm 1200 hectares, of which 400ha is under medic pastures. They run a diverse rotation including durum and bread wheat, feed and malting barley, lentils, peas, faba beans, canola and oat and medic hay. The crop mix depends on the market and specific demands on the paddock. For example, hay plays a part in their integrated ryegrass control strategy and canola, with its strong taproot, is used to break the clay subsoil. Sheep also play an important part in the business mix. A flock of 500 self-replacing Merino ewes is run for wool and another 400 Merino ewes are crossed to Suffolk rams for prime lamb production. The sheep provide diversity to the cashflow and spread risk. They also complement the cropping system by cleaning up weeds and providing organic matter in the form of dung, while screenings can be mixed in the ration fed to prime lambs housed in a feedlot in early winter. Soils vary from loam over heavy clay to loam over shallow limestone. To try to increase the rooting depth in the loam over limestone soils, where the limestone can come to the surface, the Kakoschkes have experimented with a rock profiler, usually used to reclaim roads, and a rock saw. About half a hectare was treated with the rock saw. Slots were cut into the soil and rock at intervals ranging from 40 centimetres to one metre apart, the objective being to increase the rooting depth and root access to moisture. The saw left slots about 10cm wide and up to 30cm deep filled with pulverised rock mixed with soil. The area was sown with the rest of the paddock and, following a hard finish, the benefit of rock sawing was clear, with tiger stripes of harvestable crop on and adjacent to the cuts, while the rest of the paddock had hayed-off. The following year, encouraged by the results from the rock saw, the Kakoschkes experimented with the rock profiler. This time one hectare of paddock was treated with the 2m-wide rock profiler run across the area. Basically, the profiler delves 15cm into the soil, crushing any large pieces of rock into powder and small stones. “In a hard finish these treatments gave the crops sufficient rooting depth and access to additional water allowing them to finish,” Rex Kakoschke says. “We have monitored crops and pastures in subsequent years for symptoms of lime chlorosis that we thought may occur by crushing the limestone and mixing it with the soil; but no symptoms have been seen in good or drier seasons.” Where the rock profiler has been used the Kakoschkes find the soil is much easier to work, and produces better crops in years with a dry spring and equal crops in seasons with a wetter finish. “It could be a lifetime project but we are now planning to profile about 600ha of land. With Peter’s engineering skills we hope to modify a machine for our own use.” Improving the soil is one of Rex Kakoschke’s passions; another is avoiding the development of herbicide-resistant weeds. In addition to grazing and hay, their integrated weed management program includes trying to increase crop weed competition. Some crops are sown with a John Shearer ‘Universal Cultivator’ fitted with knife points at 18cm (seven-inch) row spacing, while most cereal crops are sown with either 10cm or 17cm shares using a spreader plate to try to achieve a seed spread of at least 2.5cm across the row. Rex Kakoschke would prefer to reduce row spacing to 12.5cm (five inches) to achieve more even plant spacing across the soil surface, but this is not feasible with the current seeding system. Herbicides continue to play a role in the Kakoschkes’ weed control program but they are always looking at ways to maximise the control these provide. Last Soils GROUND COVER SEPTEMBER -- OCTOBER 2006 4 year spray nozzles were changed from a flat fan to low-pressure air induction nozzles to help minimise drift and improve canopy penetration. This change, together with a better regard for spray rig set-up and calibration, was emphasised at a Graham Betts spray day attended by Evan Kakoschke. The day was part of a TAFE Certificate III in Agriculture course. With support from the local grower group, the Yorke Peninsula (YP) Alkaline Soils Group, and sponsorship from Rabobank, the TAFE students were instructed by industry experts in subjects ranging from soil to spray technology, farm finance and the use of growth stages in nutrient and fungicide management. The Kakoschkes are actively involved in the local agricultural bureau and are members of the YP Alkaline Soils Group. They find both organisations offer them opportunities to keep learning and to share their findings with other farmers. “I want to see a return before I make a considerable investment into a new technique or technology, therefore I need to see it tested locally or on our farm to make this assessment,” Rex Kakoschke says. “Margins are continually tightening and as farmers we have to keep improving our systems, but changes need to be based on a sound return on investment.” More information: Rex Kakoschke, 08 8839 2078, firstname.lastname@example.org Between rock and a hard place Rex Kakoschke and sons Evan (left) and Peter are passionate about improving the soil and they have been testing some radical remediation possibilities. Right: wheat germinates in a paddock they treated with a rock profiler.
Ground Cover 065 November-December 2006 - North
Ground Cover 063 August 2006 - North