Surface application of agricultural lime to treat acidity in the soil profile delivers multiple benefits to the broadcare dryland farming systems in Western Australia. Soil pH measured in 2009 to a depth of 40-50 cm was increased by applications of lime applied in 1991 and 2000. The ameliorated soil pH profile, which meets the Wheatbelt Natural Resource Management 2025 resource targets (Avon Catchment Council 2005) (designed to remove acidity as a constraint to productive agriculture), has provided multiple benefits in terms of increased productivity, increased crop competitiveness, reduced weed burden, reduced risk of soil erosion by wind due to increased biomass cover and potentially reduced off-site effects which result from decreased water use efficiency on profiles with low pH. Current annual losses due to soil acidity for the WA wheatbelt are estimated at between $300-400 million or around 9% of the total crop. The treated soil profile in this trial returned $175/ha benefit from increased wheat yield in 2008 and $225/ha benefit from increased barley grain yield in 2009.
