Optlime, a bioecenomic model of soil acidity management in agricultural systems

Optlime is a model that represents the essential biological, physical and economic factors related to soil acidity management in Western Australia. The model allows users to define site and soil characteristics for an acidic scenario and then simultaneously assess likely outcomes for 2 different lime sources and application strategies. With and without liming scenarios are examined over a 20 year simulation so as to capture the long-term impacts of soil acidity management. Output provided allows you to examine the likely effect of liming on pH, exchangeable aluminium, yields, and profits. An investment appraisal is provided to show you how liming might stack up financially using a variety of time horizons. Optlime is not a lime recommendation tool, and should never be used as one. In practice, responses to liming for apparently similar situations can be very variable. The simplifications in the model do not allow us to fully account for this variability. For this reason, Optlime should be seen as an aid to understanding the management of soil acidity, not as a recipe

Extending the message of soil quality in the mobile device era

In this day and age, where everyone is time poor, making information easily and quickly available is paramount. However, with a topic as complex and as multi-dimensional as soil quality, a new approach to packaging information that is evidence-based and relevant to the local environment is required. Apple multimedia digital books provide a platform capable of delivering layers of information on mobile devices

Soil acidity : a guide for WA farmers and consultants

Soil acidity: a guide for WA farmers and consultants provides all the necessary information for effective management and understanding of soil acidity in a user-friendly handbook including many examples, diagrams and photographs.https://researchlibrary.agric.wa.gov.au/bulletins/1031/thumbnail.jp

Soil pH in northern and southern areas of the WA wheatbelt

More than 80% of the topsoils sampled fall below the critical surface pHCaCl2 of 5.5 in the northern and southern wheatbelt study areas, with more in the south than the north. These results confirm soil acidity is a serious concern throughout the WA wheatbelt when considered in conjunction with the more intensive analysis of current soil pH throughout the Avon River Basin (2005–2008). With low topsoil pH, it is likely that subsurface acidity is also a problem. For soil acidity to be managed, subsurface pH also needs to be known. In the Avon River Basin study, about half of the subsurface samples fell below the critical subsurface pH of 4.8. Maintaining soil pH above 5.5 in the topsoil and 4.8 in the subsurface will remove soil acidity and aluminium toxicity as a constraint to sustainable productive agriculture in the WA wheatbelt.https://researchlibrary.agric.wa.gov.au/bulletins/1199/thumbnail.jp

Survey of Western Australian agricultural lime sources

As a service to WA wheatbelt farmers, to assist with cost effective management of soil acidity, a survey of agricultural lime availability and quality was conducted by the Department of Agriculture and Food, Western Australia. The quality of agricultural lime surveyed varied widely between pits. High quality lime is available from limes and, limestone and dolomite sources. Twice as much of the lowest neutralising value lime surveyed would need to be applied compared to the highest to achieve the same increase in soil pH. Limes also varied in the distribution of particle sizes. Selecting limes with a high proportion of finer particles would be necessary if rapid amelioration of acidity is important. The west coast from Perth to Geraldton has abundant high quality lime sources. The number of sources diminishes moving south of Perth and east across the South Coast to Esperance. Limited numbers of inland sources of varying quality are also available. The survey was well received and if repeated has potential to be a valuable source of communication with the industry and would provide valuable information to farmers and government.https://researchlibrary.agric.wa.gov.au/bulletins/1198/thumbnail.jp

iLime an app for assessing the management of soil acidity in agricultural systems

iLIme mobile app is available for download for Apple and Android devices from your preferred app store. https://www.agric.wa.gov.au/apps/ilime Awareness of soil acidity as a constraint to agricultural production in Western Australia has led to increased use of lime, but rates remain too low to manage existing acidic soil and ongoing acidification. To invest in lime, growers need confidence in likely economic and production responses. This paper describes the development of an acidification calculator, in app form, that was developed with input and feedback to ensure that it would meet the needs and requirements of users

Variable aluminium toxicity and root distribution in acidic soil profiles

Subsoil acidity currently affects two thirds of the arable soils in the WA wheatbelt. At acidic soil pH, aluminium (Al) is solubilised from the solid phase into soil solution, creating a direct and localised toxicity to plant roots. Aluminium toxicity to plant roots constrains crop productivity by reducing root proliferation through soil, and inhibiting the capacity of roots to tolerate other constraints, such as compaction. Ongoing acidification of the subsoil is a direct artefact of the productive farming systems that are required to feed our world’s growing appetite for grain and livestock products