14 February 2007

A trial at the University of New England's (UNE) McMaster Research Station at Warialda, NSW, will bring new understanding to the popular theory that grazing cattle damage heavy cropping soils, with the resulting compaction affecting following crops.

Funded by the national Grain & Graze program and the Border Rivers-Gwydir Catchment Management Authority, the research is being carried out by scientists from UNE and the NSW Department of Primary Industries (NSW DPI).

According to the project leader, UNE's Dr Chris Guppy, the trial will point the way for further research at the McMaster Station into the long term sustainability of incorporating pasture and legume phases into northern Australian cropping systems.

"Many farmers and agronomists believe that stock have no place in modern, no-till, conservation farming systems, because of the compaction they cause," Dr Guppy said.

"But there's been little or no hard research on the subject and the McMaster Station at Warialda is admirably placed to do that work because its farm activities, soil and land use types - cracking clay vertosols, red and shallow brown basalt ridges - are typical of the northern cropping region.

"The University's work at the research station is also aligned to investigate priorities identified by the Grain & Graze program in the Border Rivers-Gwydir catchment."

Dr Guppy said the research in the compaction trial was being carried out by Honours student Philip Gray, who was measuring the impact of cattle on the physical properties of soil.

GPS technology was used to mark sites within the trial area and also another half dozen control sites outside the trial area for comparison purposes. Measurements were taken before and after the trial site was grazed with different numbers of cattle - 12 head in one 0.75 hectare paddock and three head in another paddock the same size.

"We will plant barley on the trial site in June, and before that we will conduct an electro-magnetic (EM) survey to determine if moisture storage in the soil profile was affected by grazing and, subsequently, whether the possible moisture storage difference results in reduced yields," Dr Guppy said.

"We will monitor the growth rate of the barley crop four or five times over the season, using CropCircle sensors, prior to complete canopy closure."

Dr Guppy said a separate Honours level, Grain & Graze associated project, by student Adam Altman, will look at trampling damage to cropping soils following rainfall events of between zero and 75 millimetres.

Producers invariably believe that soil is damaged, or "pugged", when cattle are left in paddocks following storm events, yet the difficulty in management required to get them off those paddocks when rainfall is likely, prevents truly integrated mixed farming from occurring.

"This experiment aims to determine how much rainfall is needed before significant soil damage occurs and how long soils take to recover from that damage," Dr Guppy said.

The results of both trials, which are expected by the end of 2007, will assist mixed farmers to make management decisions about the integration of their livestock and cropping systems. For more information about the compaction trial at the McMaster Research Station, Warialda, please contact Dr Chris Guppy, University of New England, on 02 6773 3567.

Grain & Graze Regional Coordinators
Avon Region - Linda Leonard - 08 9690 2191
Border Rivers Region - Rachel Charles - 07 4671 7900
Central West/Lachlan Region - Jodie Dean - 02 6895 1015
Corangamite/Glenelg-Hopkins Region - Cam Nicholson - 03 5258 3860
Eyre Peninsula Region - Alison Frischke - 08 8680 6223
Mallee Region - Zubair Shahzad - 03 5021 9103
Maranoa/Balonne Region - Stephen Ginns - 07 4620 8122
Northern Agricultural Region - Philip Barrett-Lennard - 08 9475 0753
Murrumbidgee Regional Coordinator - Katrina Sait - 02 6924 4633

For more information about the Grain & Graze Program in the Border Rivers Region, contact Regional Coordinator, Rachel Charles on 07 4671 7900 or mobile 0417 468 861; Richard Price, National Coordinator, on 02 6295 6300 or mobile 0409 624 297; Gillian Stewart on 02 6263 6042; Lynne Sealie on 02 6263 6021, or visit www.grainandgraze.com.au