Ground Cover North : Ground Cover 072 January-February 2008 - North
RAISED BEDS DRIVE CROPPING EXPANSION IN THE WET A high-rainfall-zone grower explains the challenges facing farmers for whom too much rain can be the main production constraint for cropping BY CATHERINE NORWOOD n The Wilson family, who farm near Winchelsea in Victoria, have been pioneers of winter cropping in southern Victoria for more than 50 years, and leaders in high-rainfall zone raised-bed farming for the past decade. Like many others in south coastal regions, they have traditionally been graziers -- although not exclusively. The Wilsons' enterprises stretch over 4700 hectares of owned and leasehold land in the Winchelsea district, with a mix of soils -- lake bank lunette loams, which are free-draining and fertile, and basalt clays, which are very hard and poorly structured. "The story goes that, in my grandfather's day, the lunettes were basically highly productive weed patches," says Lachie Wilson, who manages the family enterprises with his parents Bruce and Judy. "Eventually he thought 'Bugger it, I'm going to put crops in there.' So he did. All the other farmers in the district felt sorry for him, because he had to own a tractor. "We've always done more cropping here because of the lunette loams, and we have a good idea of the economics of cropping versus livestock. "Ten years ago when wool and lamb -- and beef -- prices were all pretty poor, it prompted us to try expanding our cropping onto our poorer basalt clays. It was all a bit 'hit and miss' to begin with." After a decade of trial and error with raised-bed farming, minimum till and controlled-traffic systems, Mr Wilson feels they have learnt a lot, and have their topsoils just about where they want them. "The subsoils are our most limiting factor now -- working out how to improve water uptake and nutrients. I think our topsoils are working pretty well. To get the full potential out of our crops we just need to get a decent season -- it's been just cutting out on us for the past few years, after a late autumn break." The current season has been the best they have had for some time, with a good autumn break and 403 millimetres of rain during the winter growing season (April to October). "We had 70mm of rain in November," he says. "If it had come a few weeks earlier it would have been just perfect." Wheat makes up 25 per cent of the Wilsons' current winter crops, with 400ha of CharaA, an AH2 spring wheat, and 350ha of winter wheats, a combination of Amarok and a new variety, GS1078, due to be released commercially by grower-owned Grainsearch in 2008. He is expecting yields in the order of six tonnes per hectare. The CharaA was planted in mid-May, at rates of between 70 and 75 kilograms a hectare, with 100kg/ha of DAP. The winter wheats were planted in the first week of May at a rate of 60kg/ha, with 90 to 100kg/ha of DAP. Planting rates are based on a UK and New Zealand style of agronomy where less seed is sown and nitrogen is used to manipulate tiller rates. Despite the lower sowing rate, yields have been at least equivalent to previous crops sown at 100kg/ha. The CharaA also had two applications of the fungicide Folicur®, one at growth stage 32 and the other at growth stage 39, a preventative control against the stripe rust that Mr Wilson says "just murdered" a neighbour's crop this year. "When we first cropped some of our basalt clay areas, the soil came up in slabs, like cement. We had to use a front-end loader to break it up. But when we renovated those areas five or six years later, the soil was much more friable. There's a lot of lime and gypsum gone into it, but the improvement in soil quality is amazing. It gives you a lot of confidence to invest in better agronomy systems." While stubble retention and no-till farming are important aspects of the soil improvement, Mr Wilson also credits improvements to the raised-bed system itself. "You're speeding up the wetting and drying cycle because the water can get away. Without the waterlogging, there's more aeration in the soil, the plant roots are reaching deeper and the plants are actually able to make better use of the water, particularly with the smaller falls of 10 to 20mm, which we get a lot of." The raised beds are crucial when it comes to managing heavier rainfall. "We had almost 100mm of rainfall in July, and without the raised beds we would have had to re-sow. There was one crop with water on it for more than two UNIFORM APPROACH TO DISEASE RATINGS BY REBECCA THYER n A standard approach to disease ratings has been instigated by the National Variety Trials (NVT) with GRDC support. NVT manager Alan Bedggood says it is important that protocols are standardised across Australia. "We need to talk a common language and this approach will bring uniformity across the country and across crops." He says uniform ratings make sense given that trials are conducted across the country and growers now have access to information from outside their state. "They need to be able to relate to the disease ratings and what it means to crop management in their own area." Also, breeding is increasingly being undertaken nationally with varieties being sold across the country, making standard ratings important. Mr Bedggood says the NVT site will use only words in the NVT database to avoid the confusion that would have occurred if the various regional numerical rating systems were used." It will also use traffic light colours to alert growers to good (green), OK (orange) and poor (red) levels of resistance. "It's important however to remember that we are describing a rating of how good (resistant) or bad (susceptible) a variety might be," he says. More information: www.nvtonline.com.au weeks -- the beds were only just out of the water -- but even it looks fine now." Mr Wilson says they have gradually introduced a controlled-traffic system to their holdings, finally bringing all holdings in-line three years ago. "Raised beds force you to use in-crop controlled traffic because you have to keep the machinery wheels aligned with the furrows. It's a no-brainer really. We now have about 1600ha laid out in raised beds for annual cropping, and for lucerne. The raised beds allow us to crop areas we just wouldn't be able to otherwise." More information: Lachie Wilson, email@example.com; Rohan Wardle, Southern Farming Systems, firstname.lastname@example.org On-farm/Diseases GROUND COVER JANUARY -- FEBRUARY 2008 6 DISEASE MANAGEMENT OPTIONS Uniform Rating Management Option Description For Growers: What do I see? For Growers: What do I do? Resistant Disease may be found but will be at such a level that no economic management is required, even in instances of high disease pressure. Trace levels of disease may be found. No economic management decisions required. Moderately Resistant Disease may be obser ved but no economic management decisions will be required. Preventative sprays not necessary but disease should be monitored. Management of seed quality may be required. The disease may be observed at very low levels. No economic management decisions required. Monitor crops for disease development. Moderately Susceptible In the presence of inoculum and in seasons conducive to disease, the disease will be seen more readily when inspecting the crop. If the disease appears early in the season then an economic management decision (preventative spray) may be appropriate. Later occurrence of the disease may not require any action. Management of seed quality will be required. In the presence of inoculum, the disease will be seen more readily when inspecting the crop. Monitor crops for disease development. In the presence of inoculum and in seasons conducive to disease, an economic management decision may be appropriate (eg, preventative spray). Later occurrence of the disease may not require any action. Susceptible The disease will be easily found in the crop. Management decisions will be required to reduce yield loss and will most probably be economic to do so. Management of seed quality will be required. In the presence of inoculum the disease will often be easily found in the crop. The disease will be observed readily in the crop. Management decisions will be required to reduce yield loss and will most probably be economic to do so. Very Susceptible Do not grow this variety if the disease in question is a regular occurrence or risk. The variety in question can be a complete loss if sown and no disease management is applied. The disease will be obser ved readily in the crop. If this variety is to be grown in areas at risk of disease development, additional management strategies are essential. STANDARD DISEASE RATINGS Rating Numbers Resistant 9 Resistant -- Moderately Resistant 8 Moderately Resistant 7 Moderately Resistant -- Moderately Susceptible 6 Moderately Susceptible 5 Moderately Susceptible -- Susceptible 4 Susceptible 3 Susceptible -- Very Susceptible 2 Very Susceptible 1 This image shows how root development and therefore plant growth are enhanced through the use of raised beds. PHOTOS: REBECCA THYER Lachie Wilson gets ready to harvest his wheat.
Ground Cover 071 November-December 2007 - North
Ground Cover 073 March-April 2008 - North