# Been applying sulfate of potash, when to test again?



## nemesis256 (Mar 27, 2021)

My potassium has been incredibly low (30ppm) so I've applied 2lbs per 1000 sqft of SOP for the past 3 months. When do I test again to see where I'm at? My soil is fairly sandy. This fall? next spring? Should I expect to always have to do this during the growing months? I guess the question is how long does it take the SOP to be effective/measurable and how long it lasts.


----------



## g-man (Jun 15, 2017)

Once a year if you are trying to do corrections, then once every 3 is fine.


----------



## nemesis256 (Mar 27, 2021)

g-man said:


> Once a year if you are trying to do corrections, then once every 3 is fine.


I think what you're saying is don't test until next spring? Since that's my next chance to make adjustments.


----------

