The Pros And Cons Of Phosphorus Nutrition

Phosphorus is an essential macro-nutrient for plant growth and sustainable soil management. Phosphorus nutrition can be challenging in acidic soils (e.g. Queensland) and alkaline soils (e.g. South Australia). To achieve sufficient nutrition, the soil needs to have a relatively high pH, high organic matter content, and moist conditions. Specific soil orders such as Vertosols, Kandosols, Sodosols, Rudosols, and Calcarosols, lack the requirements for phosphorus nutrition. The availability of phosphorus heavily relies on soil pH; the pH range for highest availability is between 5.5 and 7.0, whereas, Queensland and South Australia are both out of this range. Queensland has acidic soils, where the pH is typically between 4.0 and 5.5, and South Australia has alkaline soils, where the pH is between 7.0 and 8.0 (Figure 1).

Limitations of phosphate nutrition in South Australian and tropic soils
Phosphorus is a naturally occurring element and has a low abundance of less than one per cent
Phosphorus nutrition is sustained through high organic matter content, which a large majority of Australian soils lack organic matter (only Tasmania have organosols). If “organic matter is increased, additional benefits such as decreased erosion, improved nutrient cycling and soil fertility” will result in better soil nutrition, in particular, phosphorus (Wong & Edis, 2013).

An essential macronutrient for plant growth and soil management is phosphorus. Its nutrition is challenging in acidic and alkaline soils (e.g. Queensland and South Australia), due to the reason that phosphorus availability depends on soil pH. Phosphorus occurs in pH of 5.5 and 7.0, whereas Queensland pH is between 4.0 and 5.5, and South Australia is between 7.0 and 8.0 (Lake, p3). Therefore, both environments are out of the ideal soil pH range, making it challenging in terms of phosphorus