Environmental Science Classroom: Climate Change & Soil Moisture

We humans are largely dependent on plants grown on land-- cropland.  Our most important croplands are the planet's former grasslands, typically located in the middle of continents: the U. S. Great Plains, the steppes of Eurasia, the pampas of South America, etc.

The essential climate-derived ingredient required to grow crops anywhere on land is soil moisture. Except in times of extreme drought, I doubt if many of us dependent on plant food (with the exception of farmers) ever think about soil moisture.

Below is an illustration I prepared that links climate change (as predicted by scientific models and as borne out by the experience of the last few decades) with soil moisture. The prediction that continental interiors will be warmer and drier is particularly significant.

You can use your imagination to link soil moisture with what's on your dinner plate.

Diagram showing relationships between climate change and soil moisture. © Fred Montague

Diagram showing relationships between climate change and soil moisture. © Fred Montague

Garden Notes: Germination

As another garden season approaches, the thoughtful gardener might consider the basic conditions required for most seeds to germinate. 

Garden notes: Germination. © Fred Montague

This review is especially important when we plant seeds indoors in pots or in flats.

While warmth is generally not a problem indoors, the interacting characteristics of soil moisture (watering) and soil aeration are always tricky.

The key is a seed-starting medium with optimal texture--some larger particles (sand or perlite) to create air spaces between them and organic matter and smaller particles (e.g., silt) to hold soil moisture.

Water the pots and flats by placing them in a tray of lukewarm water. Make sure there are drainage/uptake holes in the bottoms of the planted containers.

When the surface of the soil in the pots is moist, remove them from the tray of water. Bottom watering prevents seeds from being disturbed as they might be if watering from above.

Repeat the watering process as the flats or pots dry out. Until the seedlings emerge, keep the soil surface just moist. 

When the seedlings emerge, be careful not to overwater them.

If you aren't sure about what the seedlings and soil are telling you, plant enough containers so you can try different approaches.

Experiment, Learn, Enjoy.