More research on fertiliser use needed

AgResearch scientist Tom Fraser is only too aware of the issue of fertiliser use in the hill country and is seeking funding to support work in this area. He will be looking at this whole fertiliser issue with a view to providing cost savings for farmers as well as looking at the environmental story; the benefits to the environment of using phosphate more strategically reports Country-Wide. "This area of research is critical to the financial sustainability of hill country farmers," he says. Part of this research would include identifying whether hill country actually needs phosphate-based fertiliser, as well as looking at using modern technology to spread phosphate to where it is required, rather than the blanket coverage that has been standard practice.  If, for example, farmers are only putting it over 20ha rather than the whole block, phosphate becomes viable again, he says. If they receive funding, Fraser and his team from AgResearch will carry out surveys on hill country to look at differences in phosphate levels across different terrain, contours and slopes. Fraser says there is evidence to suggest there will be marked differences. Stock camps for example are expected to have much higher phosphate loadings than the middle of slopes. Generally, he says, there is not a lot of soil testing happening on hill country and where soils are tested farmers tend to test blocks rather than different sites within a block. Otago-based pasture consultant Peter Desborough says the increase in the price of superphosphate has put a new focus on lime and while this isn't a bad thing, he says it is a shame it has taken price increases to make farmers think about their soil pH. Some soil scientists believe acidification could jeopardise the sustainability of our hill country soils, he says. "What is needed is cost-effective means to get lime onto these soils."