Resumen de Australian agricultural limestone: : What's eating Australia?
The extent of the problem can also be illustrated by the respective regional soil pH profiles ( Figure 6 ). About 75% of surface (0-10cm) soil sample are below pH (CaCl2) 5.5 in Western Australia with about 70% in New South Wales and about 30% in Victoria. In both Western Australia and New South Wales about 30% of surface soils tested are below pH (CaCl2) 4.8, with 45% of 10-20cm and 20-30cm samples in Western Australia below pH (CaCl2) 4.8.
Purity and sizing of the agricultural limestone are the key factors influencing liming efficiency. Available neutralising value and calcium level are important and some magnesium is beneficial in the agricultural limestone. Smaller agricultural limestone particles will react more quickly than larger particles which may provide pH control (buffering capacity) over a longer period of time. The biggest pH change will occur within 3-4 months and the pH may continue to increase for 6-12 months ( Figure 10 ).
The increasing need for agricultural limestone as well as the rise of limestone quarry production throughout Western Australia and inevitably the rest of southern Australia implies that the Australian agricultural limestone industry could potentially grow by 50% or an additional 1.7m tpa (1.5m tonnes at 100% CaCO3) in the near future.
