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TAS Country : February 3rd 2011
18 Tasmanian Country Friday, February 4, 2011 Soil health A special feature Scholar Read' soil then talk' to machines KNOW ALL: Once Terrapix equipment reads'' all the soil variations ina paddock. A farmer who wants to know the location of different soil types within the paddock will have better information on how to manage crops.' WE all know that effective farming needs good soil. Every farmer instinctively knows the unproductive patches in a paddock, the spots prone to dryness or that become a bog under excess irrigation. Traditional irrigation and fertilising is done for the paddock, regardless of soil variability. New precision agricul- ture methods using GPS references and variable- rate applicators and irri- gators, mean that a pad- dock no longer has to be treated as uniform. The question is, how do you get the information you need to make these decisions? An emerging problem is how to match the extensive capabilities with the cor- rect information. Spending time and capital to retrofit with variable-rate irri- gation does not make sense if you've no easy way to inform the new equipment of where to vary input and by how much. Information that is cap- tured in a way that can ''talk'' with the software used for farm management or programs the variable- rate controllers, such as irrigation equipment, is re- quired. One of the fundamental data sets is to properly identify the soil variability in a paddock. It is the productive potential of the soil that literally underlies farm productivity and therefore day-to-day man- agement. A farmer who knows the location of different soil types in a paddock will have better information on how to manage crops. Traditional soil mapping relies entirely upon the skills of the individual sur- veyor. Only surface soil variation can be seen, which means that vari- ation in subsoil conditions is unknown. Also, tra- ditional mapping is not easily digitalised -- it can- not ''talk'' to the variable- rate equipment. Terrapix is a locally ow- ned and operated business that captures thousands of individual soil conduc- tivity data in a paddock. Terrapix has used the advanced soil-mapping technique of electromag- netic induction surveying since 2001 and has mapped hundreds of Tasmanian paddocks. These data and maps are supplied as a hard copy, as a Google Earth overlay, or in a format to fit directly into existing farm management or variable-rate controller software. Soil is a complex mix- ture of water, salt and different textures. Depend- ing on the combination of these variables, different soil types conduct differen- tly when a current is pas- sed through it. For example, dissolved salt in soil water is a very good conductor and will conduct more than a very dry, sandy soil. Similarly, a subsoil layer of com- pacted clay will conduct more current than a nearby gradational soil. Identifying zones of dif- ferent soil in a paddock enables more efficient and productive farming. Soil-sampling regimens to devise more efficient fertiliser budgets can be targeted to different soil types across the paddock. Subsoil constraints such as hidden clay layers that, without careful manage- ment, can lead to rotten potatoes, can be accurately mapped and managed. Extensive trials with Simplot over the past few years have shown that Ter- rapix's soil conductivity maps match variation in within-paddock potato yield. In addition to accurate subsoil mapping, farmers want to know how their crop is progressing during the season. Crop vigour scanners are currently being trialled by Agribyte Technologies. Every time a tractor or crop duster aircraft is used in a paddock, levels of greenness are identified providing near real-time information on crop health. Farmers can source information on within-paddock crop stress throughout the growing season. Broadacre crop- pers can locate weedy areas that will require dif- ferent management from non-weedy areas when crops are in full growth. Fresh information is gained throughout the growing season that can be provided to variable- rate controllers or con- tractors for more ef- ficient paddock manage- ment. Prill technology helps strike the right balance LITTLE WONDERS: Due to the small, even size of prills, contact with the soil is improved, giving a better release of nutrients to the plant's root system. YARA Australia YaraMila Unik 16 and Tristar are unique products that con- tain a balance of nitrogen, phosphorus and potassium in every prill. The prilling technology used to produce these prod- ucts eliminates dust and improves spreading ef- ficiency. Due to the small, even size of prills, contact with the soil is improved, giving a more even release of nutrients to the plant's root system. Upon contact with the soil, the prills readi- ly absorb moisture and re- lease nutrients quickly. YaraMila Unik 16 and Tristar are ammonium nitrate-based. Containing no urea nitrogen, they are less prone to volatilisation losses. YaraMila products include a balance of nitrate and ammonium nitrogen, making the products more effective than urea or ammonium-based ferti- lisers per unit of nitrogen. Wayne Firth, business development manager for Yara in southeast Aust- ralia, has been conducting pasture demonstrations ac- ross southern Australia. These demonstrations have reinforced the benefits of the ammonium nitrate- based compound fertilisers YaraMila Unik 16 and Tri- star. Strong pasture growth has been observed over tra- ditional blends of urea/ MOP, MAP and DAP-based programs in rotationally grazed pastures. Spreading contractors have commented on the ease of use of these two products, with reduced dust and even spreading patterns key strengths. The quick growth re- sponse observed from these nitrate nitrogen-based prod- ucts has provided growers with a new option in closely managed rotationally grazed dairy pastures. Yara Australia is con- tinuing to develop use rates for these products in pas- tures, vegetable and poppy crops across Tasmania. For further information on the use of YaraMila Unik 16 and YaraMila Tri- star in these crops, contact Wayne Firth, Yara Aust- ralia, phone 0488 727 341.
January 27th 2011
February 10th 2011