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      More to fertiliser programs than just “super”If more Australian farmers were aware that nearly 90 percent of applied phosphate was effectively wasted by becoming “locked up” in forms unavailable to plants, they’d think twice about applying conventional superphosphate. Yet according to a long-standing advocate of biological farming, Jep Gates, that’s exactly the conundrum facing today’s farmers. “Just about every farmer knows that their soils need phosphorus, calcium and sulphur for optimum pasture growth and livestock performance,” he said. “That’s why they routinely apply large and increasing amounts of superphosphate to their pastures every autumn. However, many farmers would be quite surprised to learn that the vast majority of this phosphorus is wasted. “This is because most conventional phosphate fertilisers are derived from rock phosphate, which consists of tri-calcium phosphate, a stable and insoluble compound. “To make the phosphorus more available to the plant, fertiliser manufacturers use strong acids to remove the calcium, resulting in a soluble but unstable phosphate ion. “Once it is applied to the soil, the highly acidic, negatively-charged phosphate ions quickly become bound to positively-charged ions, such as iron and aluminium, and become ‘locked up’ in forms that are unavailable to plants.” An associated problem is the steady decline in microbial activity in the soil due to continuous cultivation and pesticide use over many decades. “Healthy soils should contain a diverse and active array of micro-organisms, such as bacteria, fungi, protozoa, nematodes and earthworms,” Mr Gates said. “Many farmers are already familiar with the importance of microbes in ruminant nutrition or nitrogen fixation in legumes. Microbes also play a vital role in regulating the soil environment by governing the availability of nutrients, buffering soil pH, fixing nitrogen and carbon from the air for plant uptake, digesting organic matter into humus and holding soil particles together to slow erosion. “The so-called ‘soil foodweb’ also plays an important role in converting previously-applied calcium and phosphorus that has been locked up as tri-calcium phosphate back into plant-usable forms. “Unfortunately, the size and diversity of the microbial population in most cropping and grazing systems are now insufficient to provide self-sustaining fertility or plant nutrition to meet desired production levels. “This not only decreases the amount of organic matter converted to humus and microbial activity over time, but impacts on the soil’s capacity to hold water or bind together to prevent erosion.” The answer, according to Mr Gates, is to adopt a “back-to-basics” approach to nutrition by providing plants with access to a rich source of plant-available and stable nutrients, and improving microbial activity in the soil. “Biological farming is nothing new, nor is it anything to fear,” he said. “It is simply putting the balance back into agriculture the way nature intended. In most cases, it doesn’t cost any more – it just takes a bit of a shift in your thinking. “Thousands of Australian farmers have already successfully incorporated the principles of biological farming into their operations to some extent. Many of them have reported a visible difference in the health of their soils, plants and livestock within three to five years of adopting a biological soil nutrition program.” Mr Gates spent more than 25 years as a private agronomist in the U.S. before establishing a biological farming consulting service in 1987. He established the Narrandera-based company, BioAg, with fellow biological farming enthusiast, Anton Barton, in 1999. Today, their company markets a range of “biologically active” solid nutrients and fermented liquid cultures which aim to produce a living, healthy and balanced soil for optimum plant and livestock productivity. The company’s unique approach to improving natural soil fertility is being trialled by independent agricultural organisations, including NSW Agriculture, Central West Conservation Farming Association and the CSIRO. Farmers who are interested in learning more about the BioAg approach are urged to attend the free “Improving natural soil fertility” seminars being held in major regional centres during March. ARMIDALE DUBBO WAGGA WAGGA HAMILTON SHEPPARTON |
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