Morven Lime Trial Site

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.

The main components of this project will:

  1. Introduce new soil sampling practices to detect and monitor subsurface acidity.
  2. Use large-scale acid soil management sites to test a combination of different lime rates, with and without incorporation, and investigate the impact of different soil pH targets on ameliorating subsurface acidity in the short term. In the long term we aim to attract future funding to monitor pasture response to the range of pH profiles created by the various treatments; and
  3. Survey perennial pasture paddocks to identify the current status of soil pH in layers from depths of 0-30 cm. Geolocated sites to be established as long-term monitor sites to track acidification over time.

Acid soil management site

HLN and NSW DPI are managing a trial site located in a paddock on ‘Boorook’, near Morven. This site was selected for this experiment as it has no previous liming history and has uniform soils across the paddock that are severely acidic ( pHCa < 4.5; Exch Al. > 20%) to depth.

The trial site was established, and lime spread in October 2019. The trial consists of 7 treatments investigating lime rates and the effect of lime incorporation (Inc) to a depth of about 10 cm with disc harrows, compared to surface applied (SA). The treatments were decided by the project steering committee made up of local producers, advisors, LLS representatives and the project research team. The amount of lime applied, was determined by the starting pH and ECEC and the target pH. The details for each treatment are below:

(i) Nil lime (Control)
(ii) Treatments 2 (SA) and 3 (Inc); 4t/ha lime targeting  pHCa > 5.5 in the 0-10 cm depth;
(iii) Treatments 4 (SA) and 5 (Inc); 3t/ha lime targeting  pHCa > 5.2 in the 0-10 cm depth (i.e. approximating current industry recommendations);
(iv) Treatments 6 (SA); 2 t/ha lime aimed at increasing  pHCa of the surface 0-5 cm layer > 5.5; and
(v) Treatments 7(Inc); a ‘once-in-a-generation’ application of 6t/ha lime targeting a  pHCa > 6.0

A canola hybrid was sown at the site in 2020, and wheat was sown in 2021.