Soil As A Sponge

On a very basic level the key is carbon-rich soil. Often, what is considered a water scarcity problem is really an inability-to-keep-water-on-the-land problem... It is an amazing sponge. When we lose that sponge, we have landscape degradation.

-Judy Schwartz, author of

Water In Plain Sight:

Hope For A Thirsty World

Soil is alive. In one teaspoon of healthy soil there are more microbes than there are people on this planet! Those bacteria, fungi, protozoa, and nematodes (to name a few!) build soil structure and unlock nutrients for plants to grow and thrive. In the process these microorganisms create glues and slimes that help hold the soil together and also allow it to hold both air and water (roots need to both drink and breathe!).

Imagine a piece of bread and a pile of flour. When rain hits the bread, it absorbs into it like a sponge. When rain hits a pile of flour, the water washes away the flour, leaving mini gullies and dips and then eventually dries to leave a hardened mess that cracks as it dries (did you know a paste from flour + water are how you make the glue for paper machè?). The different between bread and a pile of flour is the addition of yeast (a fungi) that creates the matrix-like structure in the dough. Fungi in the soil also creates structure, making soils more resilience to both drought and flooding. Just think which would do better on a sloped surface in a downpour: a slice of bread or a pile of flour?

According to the US Natural Resources Conservation Association (NRCS), an increase of 1% of organic matter in the top 6 inches of soil over an acre can increase that acre's ability to hold water by as much as 27,000 gallons!

That. Is. Amazing.

27,000 is also a big number that's hard to visualize. What does that mean for you? For a small garden? A 1% increase of organic matter (remember that stuff that makes the soil dark and beautiful-looking!) in a 10 x 10 ft small garden is the equivalent of an extra (55-gallon) rain barrel's worth of water stored in the soil!

For a bigger garden, let's say 1000 sq ft, it's even more! The equivalent of eleven 55-gallon rain barrels!

Or for one good-sized backyard (an 1/8 of an acre yard or approximately 5500 sq ft), that works out to be about 61 rain barrels more water that the soil is able to hold!!

This is amazing!! Isn't it?!

Imagine the potential if an entire neighborhood improved the soils in their backyards? How many gallons more of water would be held in the soil and prevent flooding downstream? How much more water would be held in the soil to support trees, crops, the landscape if there was a drought? Would it be enough to prevent wildfires? Or enough to keep streams and rivers flowing year round?

Many soils across the midwestern United States used to have between 6-10% organic matter content in the soil. The rich, beautiful prairie soils held A LOT of water. Now with our conventional, chemical-based farming techniques, we have a tendency to use synthetic nitrogen and phosphorous fertilizers that increase yields but at the expense of organic matter and unfortunately, decrease overall yields over time. Those same prairie soils, on average, now have between 0% - 2% of organic matter. A sobering reality, and yet, it is also an enormous opportunity. Imagine the immense water- holding capacity if even just 1% of organic matter was rebuilt in those soils.

For more on Soil Health, check out this NRCS factsheet on soil health: https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1082147.pdf

Or the NRCS webpage for stories of farmers across the US improving yields, profits and resilience by making soil health a focus: https://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/ma/home/?cid=stelprdb1048783