If you don't grow your own soybeans, and buy one kg per cow per day of soymeal, your balance point would be 100 grams of the premix. In reality, most dairy farms import far more phosphorus than they export. As a result, P levels have been building up in soils for many years. Feed analysis results that show increasing levels of P in forages confirm this trend. While to this point higher soil levels may have improved crop yields, many farms are now reaching the high to excessive levels implicated in water pollution.
Many dairy farms purchase little or no fertilizer.
The main source of the excess P coming on to these farms today is feed, especially in the form of mineral premix or the mineral component of commercial supplements. For decades the prevailing nutrition philosophy has been that if a little is good, a lot is good insurance. In future this may be insurance we can't afford. This information is provided as a public service, but we cannot guarantee that the information is current or accurate. Readers should verify the information before acting on it.