Phosphorus question

[Rick]

I purchased an existing home in the north Dallas suburbs. Sent a soil sample to Texas A&M for analysis. I don't have any records regarding the previous owner's fertilization schedule, if any. The response back from A&M was that I needed to add phosphorus at a rate of 2.1 lbs per 1000 square feet of 0-46-0. No other recommendations beyond a normal mid-summer and early fall application of N.

Lawn area is slightly less than 8000 square feet, so 16 lbs of triple superphosphate should be enough. I can get a 20 lb bag from Amazon. I have a Scotts mini broad cast spreader. Any idea which setting will get me a 2.1-ish pound-per-1000 sq foot application rate? I'm trying to avoid measuring a test area and weighing the fertilizer used.

Second question: How often do you see the need for a phosphorus-only application. Any other time I've added phosphorus, it has been a component in an all-purpose fertilizer. I'm asking because it would be cheaper long-term to buy a bigger bag, but I just don't think I'll need to do another phosphorus-only application in the future. First experience with a Texas lawn, though, so I'd appreciate it if anyone can give some insight into this.

 

[lawn_addict]

for the spreader setting, i'd still recommend doing a quick test area if you can. the settings on scotts spreaders can vary quite a bit depending on the fertilizer granule size, and phosphorus products like triple superphosphate don't always flow the same as standard lawn fertilizers. a small test strip can save you from accidentally overapplying.

as for the phosphorus, it's not something most texas lawns need on a regular basis unless a soil test specifically shows a deficiency. since texas a&m already tested your soil and only recommended p this time, i'd probably just buy the 20 lb bag, apply what you need, and then retest in a year or two before adding more. once phosphorus levels are corrected, they tend to stay around much longer than nitrogen, which gets used up pretty quickly.

sounds like you're already doing the right thing by starting with a soil test instead of guessing. that's more than a lot of homeowners do.