Sunday 24 March 2013

Sub-soil testing could lead to nitrogen savings

The Australian Stock Journal reports on research revealing that many growers could make savings on nitrogen fertiliser by conducting subsoil testing to obtain a more accurate picture of nutrients available to their crops.

Apparently, few growers currently conduct nutrient testing in the subsoil, instead focussing on the topsoil.

The Grains Research and Development Corporation (GRDC) supported research is being conducted in WA by Murdoch University, CSIRO and the Department of Agriculture and Food (DAFWA). It has shown that, in many circumstances, nitrate stored in the sub-soil is available to crop roots.
Project leader Richard Bell, Professor in Sustainable Land Management at Murdoch University, said this meant many growers could potentially reduce nitrogen fertiliser rates and applications.
“Situations where subsoil nitrates are available to crops include heavier textured soils and drier seasons when nitrates are unlikely to leach away before roots can reach them,” he said. “However, access to subsoil nitrates by crop roots can be reduced by soil constraints such as hardpans or aluminium toxicity.”

Read more here.