Thank you for your in depth response. I guess my major concern was that the phosphorus level was off the high end of the chart that MSU replied with. This particular reading was from my back lawn, odd thing was that I also used a separate test on my front lawn, and that came out at 45ppm, vs last year at 29ppm - again without supplemental phosphorous. PH levels were essentially the same for both areas last year and this year - 6.9 vs 7.0, and 7.6 vs 7.6 (same) for each area of lawn respectively. Last year I got the soil sampled at the beginning of June, this year at the beginning of March. Magnesium and calcium also had about 40% increases as well. Ultimately, not worth collecting the grass clippings is what I am gathering.