I don't see how it helps in turfgrass maintenance, and I said so at the Northern Green Expo.

Liebig's law of the minimum says that growth is controlled by the level of the most limiting nutrient. Because there are 14 essential mineral nutrients, one could think that any of those elements might be limiting. But in practice, nitrogen (N) supply controls growth.

For more about N and growth, nutrient uptake, and nutrient demand, see Kussow et al. on Evidence, regulation, and consequences of nitrogen-driven nutrient demand by turfgrass.

After recognizing that N supply controls growth and nutrient demand, it follows that one can ensure the grass has enough of each element by keeping each above a minimum level and then adjusting growth as required with nitrogen.

These three articles explain how this approach can be implemented:

• The (new) fundamentals of turfgrass nutrition
• Just what the grass requires: using minimum levels for sustainable nutrition
• Simplifying soil test interpretations for turf professionals