A few posts back I talked about how I found it useful to compare a 30 day running average growth ratio to a 30 day running average nitrogen genki. This would tell me how my grass was growing and how much nitrogen I had applied compared to the standard level which I have determined to be about 2/g nitrogen per square meter per month at a 100% growth potential. After thinking and using that tool for a few months now, I wondered about the other nutrients. Last year I had issues with the grass not growing as expected and it turned out to be a phosphorus deficiency probably made worse by regular phosphite applications. The growth ratio model showed that the grass was growing too slow and in reality it probably was as we suffered from issues caused by slow growing turf such as Anthracnose! The more experience I get with the growth ratio model, the more valuable it becomes as a tool to help me keep the growth rate where I want it and plant health issues to the minimum. Most issues I have ha