The value of information from research to enhance testing or monitoring of soil acidity in Western Australia

The soil acidity research and extension program in Western Australia is made up of a number of projects, all of which are working towards the overall aim of helping farmers to manage soil acidity profitably. As a means of achieving this aim scientists are undertaking research to provide information that will enable farmers to better quantify potential yield losses due to subsoil aluminium, and to adopt liming strategies to prevent these losses. In this paper we present estimates of the value to farmers of information provided by this aspect of the research. A bio-economic model is used to calculate the profitability of liming for different conditions and Bayesian Decision analysis is employed to estimate the payoff resulting from incrementally refining a lime strategy in three steps. The first step was the adoption of Strategy 1 which is a broad-based liming strategy. This reflects current practice in Western Australia where most lime is applied at 1 t/ha at around 10 year intervals. The second step (Strategy 2) is the adoption by farmers of more refined strategies, according to region, rotation and soil type. This would lead to higher expected profits but is not necessarily optimal. The third step (Strategy 3) is where a farmer is able to use information about the relationship between subsoil acidity and yield to refine the liming strategy on a paddock by paddock basis. The results indicated that the value of current information aimed at improving management of soil acidity is high. However, the value of additional information generated by current research aimed at improving the certainty regarding yield response is lower. While moderately high in the low rainfall zone, the information is of less value to farmers in the medium and high rainfall zones. This may have implications for the future focus of acidity research and for defining a set of indicators for monitoring sustainability.