# Extending the beer analogy

I’ve explained how MLSN works by telling a story about beer. Specifically, about a natural and logical method to figure out how many beers to buy at the store prior to an upcoming party. No calculator required. If you haven’t heard this one, I explained it in item 4 of this MLSN newsletter.

The point I’ve tried to make with that story is how MLSN works, and how the use of MLSN guarantees that one will supply the grass with all the nutrients it can use.

This beer story can help explain something else. Soil nutrient analyses (soil tests) should be used for the purpose of determining how much fertilizer to apply. Not for finding if soil nutrient levels are at an “ideal” level. There is no ideal soil level, but there are deficiencies when grass demand for a nutrient exceeds supply.

To find the amount of beer I need to buy at the store, I consider how many beers might be consumed at the party, add to that a little bit extra to make sure we won’t run out, and then subtract the amount of beer I already have. If I think we may drink 40 beers at the party, but I already have 50 in the garage, then I don’t need to buy any at the store.

That’s how it works when doing soil testing and using MLSN. One finds out just how many nutrients are required as fertilizer.

Trying to use ideal levels of nutrients in the soil would be like deciding there always needed to be 120 beers in the garage. But that’s not efficient. If I go away on holiday for a month, I don’t need those beers there. And if I have a big party when I return home, with 200 guests, then I need a lot more than 120 beers for that. It doesn’t make sense to keep an “ideal” amount of beer because the amount needed depends on what’s happening with the demand for beer. The ideal amount might sometimes be 120, but it is usually going to be a lot less, and it could sometimes be more.

That’s how it works for turf too. When grass is dormant, it isn’t using nutrients. When it is growing fast, it has a high demand for nutrients. But the demand also has a maximum, which is the amount the grass grows.

Using soil tests and MLSN to work out the site specific nutrient requirements takes care of all this almost like magic. MLSN makes a generous estimate of demand, adds a little bit extra just to be sure, and then accounts (with soil testing) exactly for supply.

Cheers.