Well the most accurate answer is all of them. But from our vantage point there are a few to really pay attention to. Those variables include:
- Percentage of Organic Matter
- Nitrogen (N)
- Amounts of phosphorous (P) and potash (K) in the soil
When these nutrients exist in proper amounts and ratios you have only to add about 3 to 4 pounds of nitrogen per year per 1,000 square feet of turf. Of those three to four pounds 1/3 should be applied in the early spring and the remainder in two applications, one in mid-fall and the last in early winter.