Trials in central NSW showed that 2 forms of liquid P fertilizer delivered similar yield responses to the same level of P applied as MAP on a deficient soil with low PBI.
Higher cost per unit of P with these products, meant that MAP was still the more economic form of P in this environment.
Rock phosphate was also tested in this trial, with no yield increase over the 4 years of the trial.
Prepared by Carol Rose, NSW DPI, with technical input from Col McMaster, NSW DPI. Chart from GRDC article “The most profitable phosphorus according to science“-