Wheat response to increasing potassium rates on northern sands
APAL has joined with Summit Field Research and Summit Fertilizers to run a test in Western Australia which is investigating the conventional wisdom on soil test methods for potassium (K).
While traditional methods have been providing valuable information on some soil types, there is growing concern that in some soil types and circumstances these methods are providing questionable recommendations for the economic use of K fertilisers.
Our largest data set of field trials (BFDC) doesn’t allow for a comparative analysis between the performance of soil K tests. In fact, it is becoming increasing evident that within the critical range of the Colwell K and Exchangeable K, the relationship is not 1 to 1.
The trial site will investigate the performance of several potassium existing and new methods against crop response to applied K across several years. It is hoped this will increase the confidence of advisers and growers to provide improved guidelines to manage and profit from their K inputs.
The methods being used are Colwell K (Bicarbonate), Exchangeable K (Ammonium Acetate), Exchangeable K (Ammonium Chloride/Barium Chloride) and DGT K (Diffusive Gradient Thin-Films).