Precision nutrient mapping in for dryland agriculture in North East Victoria

Occasional project newsletter and update. March 2021

Established in 2019, this project is examining the benefits of targeted nutrient management in grazing enterprises.

We know there is a lot of variation in soil characteristics within paddocks. However, in most dryland grazing systems, the conventional approach to nutrient management is to take one soil sample across a paddock. While this is quick and cheap, it hides the paddock variability that occurs in nutrients and pH. As a result, some areas are over-fertilized (with the potential for off-site impacts and is a waste of money) while other areas do not receive the nutrients required to sustain a profitable and resilient pasture base. This project is trying to better understand farm scale soil variability and if there are efficiencies to be made in the application of scarce and increasingly costly inputs. Four farms at Bungeet, Benalla, Earlston and Longwood are partnering in the project. At each site, paired paddocks of similar size and soil type are being used to compare the economic response to variable rates of fertiliser and lime. On each farm, one paddock – the Precision Paddock has been sampled intensively to identify the variation in soil nutrients and pH. In this paddock, fertilizer and lime have been applied at different rates to address the within paddock variation. The Control Paddock receives fertilizer and lime based on the paddock average. Stocking rate and animal performance data from both paddocks are being collected by participating farmers to enable an economic evaluation of the different approaches. By using stocking rate differences between the paddocks as a measure of productivity, the project aims to examine how precision application of fertilizer and lime compares to paddock averaged approaches to soil management.

Demonstration Farm Information

Matt Plunkett at Longwood

Enterprise: Sheep

Land and soil description:

Phalaris based pasture on soils derived from granite (sandy clay loam)

Rainfall average: 711 mm

Andrew and Jane Marriott at Benalla

Enterprise: Beef

Land and soil description:

Phalaris based pasture on old alluvial soils (clay loam)

Rainfall average: 711 mm

Don and Ali Piper at Earlston

Enterprise: Sheep and cropping

Land and soil description:

Annual pasture on creek flats (sandy clay loam)

Rainfall average: 609 mm

Steve and Doug James, Clint Nolan at Bungeet

Enterprise: Sheep

Land and soil description:

Annual pastures on sedimentary and granite derived soils (clay loam)

Rainfall average: 546 mm

 

Project update May 2021

Participating farms have been visited in summer 2020/2021 to see how sites are progressing. Paddocks have received their nutrient applications, with livestock continuing to graze. Annual grass weeds are being managed at Earlston and Benalla sites. Water supply in paddocks is OK and not limiting. Feed base is good as a result of the good season. Landholders are assessing pasture growth and matching stocking rate as required. Project group will get together in May to monitor sites to assess the need for changes in stocking rates.

This project runs across two years and receives support from the Australian Government National Landcare Program. It is a partnership between Gecko Clan Landcare Network, Meridian Agriculture and Agriculture Victoria. For more information, contact Kerri Robson on 0418 140 710

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