However, work conducted by a soil scientist with DPI Victoria has found that sub-surface banding of organic matter will have the best effect is a finding that may improve efficiencies significantly.

Renick Peries said large scale sub-soil applications of animal manures could improve even the hostile, acidic soils of Victoria’s Western District.

Dr Peries said improved productivity resulting from subsoil manuring was caused by changes in the soil which led to better water and nutrient use efficiency by crops.

He said there had been long-term work in finding the best way to improve soils.

“Subsoil manuring in Victoria has progressed from raised bed and controlled traffic work undertaken by Southern Farming Systems (SFS) and DPI since 1996,” Dr Peries said.

“This work demonstrated the need to develop a connection between the topsoil and the subsoil on raised beds which would improve the movement of water and nutrients deeper into the soil,” he said.

“Then in 2004, DPI and SFS invested in a prototype machine that would deliver the organic matter at depth in the soil.

“The idea advanced when a major research component carried out by La Trobe University between 2005 and 2007 demonstrated lasting changes in the hostile subsoil properties in the major cropping soils of the high rainfall zone in Victoria with subsoil manuring.”

Trials commenced in the growing season of 2009-10 and poultry manure from a broiler farm was used in each.

The trial sites are at Derrinallum, Penshurst and Winchelsea, all with the volcanic soil type found through Victoria’s Western District.

A commercial machine, recently developed by the Geelong director of SFS John Sheehan, is capable of manuring one hectare of land in one fill and has six rippers which cover a width of six metres.

Dr Peries said more people now wanted to know about subsoil manuring after results from the on-farm trials showed the method was delivering results.

He said currently the costs of the practice, due to the volumes of manure required and the energy needed to band the manure at depth, put many growers off.

However, he said local farmers who had done the banding work were talking up the benefits to the soil of the application of manure.

“Combined with a cost benefit analysis, I think we are bridging the gap in knowledge and bringing others on-board.”