Hi, thanks for the question.

Potassium in the form of potassium sulfate and potassium chloride if overapplied can cause burning in the lawn.  Unfortunately, the photos don't really show enough detail for a good diagnosis.  The potassium added could be reasonable depending on the size of the lawn and whether it is an annual rate (which should not be applied all at once).  A new soil test is recommended (Home | MSU Soil Test). Overapplication can cause burn where tips and edges of grass blades turn brown or yellow, resembling scorch marks. Over-application of potassium can disrupt the balance with other nutrients like nitrogen and phosphorus which may slow down growth.  Potassium does leach out of the soil.  More frequent mowing is suggested to reduce potassium stress in the turf. Do not add additional potassium until levels come down to the appropriate ppm.

 Check out the following link:

Best Management Practices for Soil & Nutrient Management in Turf Systems | Center for Agriculture, Food, and the Environment (umass.edu)

I hope this is helpful.

Hi, thanks for the question.

Potassium in the form of potassium sulfate and potassium chloride if overapplied can cause burning in the lawn.  Unfortunately, the photos don't really show enough detail for a good diagnosis.  The potassium added could be reasonable depending on the size of the lawn and whether it is an annual rate (which should not be applied all at once).  A new soil test is recommended (Home | MSU Soil Test). Overapplication can cause burn where tips and edges of grass blades turn brown or yellow, resembling scorch marks. Over-application of potassium can disrupt the balance with other nutrients like nitrogen and phosphorus which may slow down growth.  Potassium does leach out of the soil.  More frequent mowing is suggested to reduce potassium stress in the turf. Do not add additional potassium until levels come down to the appropriate ppm.  Check out the following link:

Best Management Practices for Soil & Nutrient Management in Turf Systems | Center for Agriculture, Food, and the Environment (umass.edu)

I hope this is helpful.