Friday, March 19, 2021



"Drought" is a mega-topic. It can mean many different things depending on your relationship with water. Consequently there are many different "Drought Indexes" that attempt to quantify "Drought". The Palmer Drought Index is probably the most common.

For example, if you are a duck hunter on the Mississippi flyway then you are very concerned about the sloughs and potholes in the Dakotas, Minnesota, western Manitoba and Saskatchewan.

If you grow un-irrigated corn then you care about the moisture stored in the top five feet of your soil profile.

If you grow irrigated corn you care about the the water-table and the possibility that your pumps might start cavitating if it drops too low.

If you are a wheat farmer you would love to see saturated soil going into the growing season and then long, sunny days with minimal rain and wind right up until harvest.

If you go boating on a reservoir or pull water from one, then you look to the snow-pack.

In my part of Michigan, drought tends to be local. Storms can cut diagonally across a field and one half of the field can bear a good yield and the other a disappointing one. One ran, just before pollination can make all of the difference in the world.

A dry spring is not always bad. Fields dry out and can be planted earlier. Drier fields have warmer temperatures in the upper few inches where seeds are planted...and germinate. Farmers have a limited ability to plant deeper to get the seed into soil moist enough to germinate the seeds.

As long as the rains come.

We are a large country. Usually, dry in one part of the country means more rain in other parts. The Gulf of Mexico evaporates pretty much the same amount of moisture every day through the summer, year-after-year. The $60B question is "What tracks do those storms take?"

We tend to end up doing OK as long as they don't all run down the same track, all summer long. It is better when they wander like a stumble-bum trying to take a leak on a lamp post.

Locally it has been dry. We didn't have much snow this year and the last few rain episodes we had were fronts that came in from the northwest and they did not drop much water. There is very little water in the burn pit. 

Bonus images:

This particular drought index (PDSI) focuses on the amount of moisture stored in the soil at levels available for plant up-take. Much of the Corn Belt is pretty darned dry.

1 comment:

  1. Thanks for the simple overview. Very informative. We draw from a reservoir and had the usual good snow pack this year. Good to hear what other people are up against. So much depends upon blessings. What would happen if we lost that?


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