Acid Soils Program
Why acid soils?
Soil acidity affects more than 50% of intensively used agricultural land in NSW and approximately 23% in Victoria, and is especially prevalent in the higher rainfall areas in our region. If we do not address acid soils now, further acidification will threaten future agricultural production.
Recent research on soils in the NSW Southern Slopes suggests that in most cases, current rates of lime application are not addressing the current soil acidification rate. An effective liming program should aim to increase soil pH (CaCl2) to a target of 5.5 in the top 10 cm, not 5.0 as has been the current practice. This will provide sufficient lime to raise pH in the surface soil and allow for excess lime to leach into deeper subsurface layers (5 – 20 cm) and slowly increase pH at depth.
Lime that is top-dressed moves very slowly into the subsurface layers, depending on soil type, rainfall and lime application rate. It is known that effective incorporation of the lime after spreading ‘speeds up’ the reaction of lime with the soil, to the depth of cultivation.
HLN in conjunction with NSW DPI have set up two new trial sites that will be looking at these questions – different liming rates, top-dressing lime vs incorporating and the effects on crop and pasture growth. Another issue being looked at is pH stratification – acidic layers in the soil that may be impacting crop and pasture growth but are not being detected by traditional soil tests that bulks samples into 10 cm intervals.
A background on each of the projects can be viewed by clicking the site icons below.
Current & Past Acid Soil Project Sites
‘FutureSOILS’ Project: 2020-2023
The ‘Future Soils’ project is funded by the Australian Government’s National Landcare Program to improve on-farm management of acid soils. The project is managed by FarmLink and is a collaboration between NSW DPI, the Australian National University, FarmLink, Holbrook Landcare Network, Central West Farming Systems, K-Line Ag and Westlime.
HLN is hosting one of the five trial sites for the 3-year project, a replicated farm-scale site at Burrumbuttock. The trial consists of 7 treatments investigating 4 different liming rates … READ MORE
‘Managing Soil Acidity in Permanent Pastures’ Project: 2021 – 2028
The Meat & Livestock Australia (MLA) funded Producer Demonstration Site (PDS) project – ‘Managing soil acidity in permanent pastures’ is investigating top-dressed liming strategies in non-arable pasture systems where lime incorporation is not possible or preferred.
The project involves three lime demonstration sites:
- Mannus & Holbrook (established in February 2021), and
- Rosewood (since 2017) … READ MORE
‘New Approaches to Tackling Soil Acidity in Perennial Pasture Systems’: 2019 – 2021
The ‘Tackling Soil Acidity’ project, is a 2-year project funded by the Australian Government’s National Landcare Program, with contributions from HLN, NSW DPI and the Grasslands Society of NSW Inc.
HLN and NSW DPI are managing a trial site located in a paddock on ‘Boorook’, near Morven. This site had no previous liming history and has uniform soils across the paddock that are severely acidic. The trial site was established, and lime spread in October 2019 … READ MORE