simple identification of on-farm lime sources in the western region
The project aims to develop a fact sheet which will assist growers within the Kwinana East Port zone in being able to identify on-farm opportunities for assessing and extracting alternatives to lime from their own property. This includes conducting a quality assessment of the product and assessing if the product found on their property will provide an economically viable alternative to externally sourced lime products.
Project lead organisation
MapIQ, and Merredin and Districts Farm Improvement Group (MADFIG)
Soil acidity continues to be a major constraint to production for Western Australian (WA) grain growers. At the recent Kwinana East port zone Regional Cropping Solutions Network (RCSN) meeting in August 2017, members identified that the cost of amelioration for soil acidity in the Kwinana East zone is very high (are the benefits worth the cost?), and identified that they wanted growers to be able to assess whether they had a potential source of lime/or lime alternatives on their own properties.
Soil surveys since 2005 have shown that 70% of soils in South West WA are below recommended pH at the surface (0-10cm), and continued monitoring has shown that this constraint in the majority of the affected area is remaining static (at best) or deteriorating. Although rates of lime application appear to be increasing, they still fall well short of what is required to ameliorate existing, and counter ongoing, soil acidification. WA, where more than 70% of surface soils are below appropriate pH levels, has one of the leading programs in Australia for combating acidification, but the lime application rates are still much lower than what is needed to avoid irreparable damage (Gazey et al., 2013).
Growers in the Kwinana East port zone agree that costs of getting lime delivered and spread range from $42-$50/tonne which is a considerable cost to their farm business (pers comm Kwinana East RCSN, August 2017). Recent use of on-farm high pH Morrell soils as a lime alternative by Kalannie growers has generated interest from other growers who can see potential in the practice. The product may be of lower neutralising value (NV) but can be applied at higher rates, and the overall cost ($/hectare) is less than imported lime due to the savings in freight. Dolomite is also a source of lime that is located further inland and should be compared to on-farm sources when calculating the economics of using outsourced products for amelioration of acid soils.
This project scope has been developed through ideas from the Kwinana East port zone RCSN and growers at Local Open Forums held in the Kwinana East port zone in August 2017, to provide enough information to growers to help them identify on-farm lime sources, and determining whether these can meet (or exceed) the cost/benefit ratio of more traditional coastal sources.
By February 2019, a fact sheet will be produced (electronic) titled “Locating and assessing alternatives to lime on your own property” that will include all of the points that need to be considered if a grower wants to find, assess, and use on-farm products to help alleviate acidity on their property.
Results and Reports
This project was funded by GRDC