Do you, dear reader, know what makes bread, bread?
Let’s conduct an experiment. Imagine (or DIY) this setup: you have two bowls, one with flour, and another with a slice of bread. Take a glass of water and pour it into both the bowls. Note the observable differences. When poured into the pile of flour, the water sinks into the middle and runs off down the sides, taking the flour with it. If exposed to the sun, the water evaporates, and the wet flour dries and hardens. The bread, on the other hand, absorbs the water to the extent that it can. The water does not take away any flour with it; instead, the bread actually holds it. It stores the water. If exposed to the sun, evaporation does not easily occur, and the bread’s structure holds. More importantly, it still retains its capacity to hold water.
But why is that so? Is it because bread is more porous than flour? If we were to poke holes in the flour, would it increase its water holding capacity? Turns out, it does not. The water would deposit itself in more places, but it ultimately exhibits the same behavior. So what is it that makes bread, bread? And why is it important?
The only difference between bread and flour is the presence of yeast. Yeast, which is a single-cell fungus, does the quiet work [1] of converting flour into bread through fermentation, which releases carbon dioxide and creates a structure with air pockets. It is this biological activity that makes the bread a sponge, allowing it to soak up water.
This demonstration helps us understand two things about our environment. The first is that soil acts very similarly to the demonstration depending on the amount of biological activity in it. Didi Pershouse, a soil sponge strategist, author, and educator, describes healthy soil as “intelligent” and “carbon-rich [2].” In healthy soil are many micro and macro-organisms that break down biological matter and actively seek out water and nutrients, creating a sponge-like structure with soil particles that holds water and sequesters carbon. These microorganisms include mycorrhizal fungi, which form symbiotic relationships with plant roots to increase nutrient uptake.
This brings us to the second point: our soil sponge is extremely important in the fight to mitigate climate change and its effects on our environment. Healthy soil is key to protecting us from several natural disasters, including droughts, floods, famines, landslides, dust storms, earthquakes, and even a sea-level rise. Healthy soil can also filter out chemicals and pollutants that are used in traditional farming (although it won’t do this forever), and protects plants from their harmful effects.
Soil with little to no biological activity, on the other hand, is extremely prone to natural disasters, causing mass soil erosion, pollution, and threats to the lives and wellbeing of all life forms. More importantly, ‘flour-like’ soil cannot sequester carbon and will not hold water, no matter how much farmers till that soil. This is because traditional farming methods, where the use of harsh chemicals and heavy equipment is ever present, disturb the soil and inhibit biological activity. This leads to lower crop yield and quality, affecting income generation and food supply.
Soil degradation is unfortunately not just a domestic problem, either. With several countries relying on international supply chains for food, and with several nations experiencing increasingly frequent climate events, protecting our soil is of international concern. The topic should also included in conversations surrounding reducing CO2 emissions as unhealthy soil actually releases more carbon dioxide into the atmosphere and amplifies global warming [3]. Therefore, it is vital that countries incorporate soil management practices to increase indigenous plant cover in wastelands and incorporate sustainable food production practices such as reduced tillage, year-round crop cover, smart irrigation, and natural fertilizing and pest management techniques.
As for us, dear readers, we can always do our part by joining tree planting efforts and increasing the plant cover in our apartment complexes and community spaces. We can also advocate for more green infrastructure in urban spaces to help sequester carbon, reduce city temperatures, and mitigate climate events.
Keep your soil spongy!
References:
[1] Anna-P. (2024b, October 3). What does Yeast do in Bread? | The Online Pastry School. The Online Pastry School. https://becomeapastrychef.co.uk/what-does-yeast-do-in-bread/
[2] Biodiversity for a Livable Climate. (2016, June 15). Water, Soil, Health and Climate- Connecting the Dots with Didi Pershouse [Video]. YouTube. https://www.youtube.com/watch?v=CgzNeg88g4c
[3] Rastogi, Monika, Shalini Singh, and H. Pathak. “Emission of Carbon Dioxide from Soil.” Current Science 82, no. 5 (2002): 510–17. http://www.jstor.org/stable/24105957.
