Fertilizing a Large Lawn
I have an 85,000 sq feet lawn that can cost a lot to keep fertilized. I was able to purchase a liquid nitrogen fertilizer that is cheap and easily applied with a spray tank pulled by my lawn tractor. Is there a source of liquid phosphorous and potassium?
Start with a soil test and see if you need to add these two nutrients. Years of using complete fertilizers (those that contain nitrogen, phosphorous and potassium) on farm fields, lawns and landscapes have resulted in high to excessive levels of these nutrients in the soil. Plus phosphorous and potassium are used by plants in smaller amounts than nitrogen and generally don’t move as quickly through the soil. That means most gardeners don’t need to add much, if any, of these nutrients. Contact your local extension office or check the yellow pages for a state certified soil testing lab. They can provide the needed information for submitting a soil sample for testing. The test will tell you when and how much to apply. This is usually much less than your nitrogen applications. Applying these nutrients in a granular form once or a few times over the next few years may not be as cost prohibitive as you think. If you still want to use a liquid form of these nutrients contact your local farm supplier or landscape company. As you discovered, there is a limited market and therefore a limited supply of bulk liquid fertilizer available to home gardeners.