In the initial install, I added compost that was high in calcium because the company added lime to their compost. I also added gypsum at that time. I didn’t know there was a lot of calcium in the compost at the time. That was 5 years ago. Back then I used the Morgan soil test which is a very weak acid. They recommended calcium. I don’t use that test anymore because it doesn’t show you what’s in the soil thus they said to add more when it didn’t need it. Over the years I added gypsum a couple more times and lime once. In the last year and a half I really started studying. This year I started testing all these fruit tree areas. That was actually in September when I finally realized that I have typically 2250-2600ppm of calcium in those areas. A few have less at 1800ppm. The areas with less are areas where I only used irrigation, and compost originally. No compost has been added since original install. Lots of mulch initially installed as well. After year 3-4 I started having some disease issues on some trees. It appears K related mostly. K has dwindled in these soils over 5 years to around 19-40ppm. I only recently started adding it.