By Stephen Leslie
2022 was a hot dry summer across the region, and in fact, across the Northern Hemisphere.
Concerns about water availability in Vermont were recently prompted by the moderate to severe drought that began in 2020. In 2021, some wells in the northern tier of Vermont began to go dry. Last season, for many farmers, the growing season was a bust. Long-term climate modeling suggests we should anticipate more summers like this.
A recent climate impact assessment issued by the University of Vermont shows that over the last 20 years, unpredictable and unseasonable "flash droughts" have become a common feature for farmers to contend with. Although overall precipitation has increased by 20% since the 1970s and is predicted to increase another 20% by 2050, the water is tending to come all at once, in potentially destructive "precipitation events" and summer dry spells have grown longer and more severe in their impacts, not only on farms but also putting new stressors on forest ecosystems and wildlife. Additionally, shorter winters and higher summer temps increase evaporation from land and bodies of water.
In response to these drying conditions, the state of Vermont passed a new law that went into effect in July that calls on farmers to monitor their water use which requires that any agricultural operation that draws a minimum of 10,000 gallons in a 24-hour period from surface water must register with the state and record their use. The aim of the law is to make our lakes, rivers and streams more resilient in the face of climate change.
While this data will certainly be useful, measuring and regulating water use at “the tap” is starting at the endpoint.
If we want to get serious about ensuring our water supply remains stable and abundant into the future, we need to consider how to infiltrate and hold water better for resilience through all extremes.
If something like tropical storm Irene (11 inches of rain in 24 hours) hit in 1750, the old-growth forests that once covered our region would have infiltrated all that water without catastrophic flooding. Old forests hold 4 times more water than young ones and 10 times more than even healthy agricultural fields. Plus the ubiquitous bio-engineering of beavers and extensive healthy wetlands slowed water and kept aquifers replete.
The problem is, we are still quantifying and measuring water as if it were a "thing." We need to take a page from the Indigenous water protectors (who have been leading the resistance to block new tar sand oil pipeline construction on their homelands in the Dakotas and elsewhere) — when they remind us that "water is life!”
3.8 billion years ago rain used to fall on the bare rock of empty continents and run right back to the sea. It was only after fungi and algae got together to venture out of the oceans and colonize land that the soil formation process began and consequently that freshwater also gained a foothold on land (cycling through soil, plants and animals).
That original soil carbon sponge formed from the detritus of primitive plants and animals is the basis of all terrestrial life and there would be no water cycle without it. So, even though all life depends on water, water depends on soil to catch it, hold it and slowly release it again.
What can we be doing now to create fully functioning forest, farm and municipal landscapes that mimic the capacity of the ancient forest?
A secure clean water supply must begin with healthy soil.
On our small diversified farm, we are feeling the impacts of this dry summer on every front, after all, water is the essential ingredient!
For example, with the lack of precipitation, the regrowth on our hay fields has been reduced by 40% or more, which in our context means there is that much less grass for cows to graze on the fields that we fold into the grazing rotation after the first cut and a reduced bale count on the field where we typically bale second cut instead of grazing because it is some distance from the barn.
When it gets dry like this, the farmer puts in the same amount (or sometimes more, as in moving irrigation pipe) of work and energy expenditure but reaps lower returns. For us, this translates into having to spend more on bought-in hay — and we can expect the price to go up, as operating expenses have increased and yields are down across the region.
However, we are also seeing some positive results through efforts we are making to mitigate and adapt. For instance, we have a field where we grew vegetables for 12 years. When we started, the soil organic matter (SOM) in this field was 3%. By applying compost at a rate of 20 tons/acre and the extensive use of cover crops, we managed to raise the SOM to 6%.
According to the Natural Resources Conservation Service, every 1% increase of SOM in soil will hold an additional 20,000 to 26,000 gallons of water, which means in a drought, we potentially retain an additional 60,000 gallons or more per acre on this field.
In our pasture system, we have identified micro wetlands, typically classified as "marginal land." By excluding cows from these zones, we have seen them jump back to life as functional wetlands, infiltrating and holding water while vastly increasing the biodiversity of the system overall. We have begun introducing trees back into our pastures. Pilot studies have shown that when planted at a density of 20 trees/acre in a silvopasture system, the cooling and soil buffering power of trees increases forage yields and livestock gains by as much as 20%.
In our market garden, we switched over to a no-till approach. When the soil is no longer disturbed through tillage, plants can re-establish a symbiotic relationship with fungal mycelium. The permanent beds are healed from compaction and the deep loamy mulch that develops holds water even on our sandy soils.
Climate scientists of the UN’s Intergovernmental Panel on Climate Change tell us that we have an eight-year window to halt CO2 emissions if we are to avoid the most catastrophic consequences of irreversible abrupt climate change. In order to meet our binding greenhouse gas emission reduction targets as established under the passage of the Vermont Global Warming Solutions Act of 2020, to clean up our rivers and lakes, and renew our agricultural economy, we need to elevate healthy soil as an essential ingredient to solve the climate and biodiversity crisis.
Healthy soil practices have proven to be the most cost-effective way to sequester carbon. Simply reducing GHG emissions won’t be enough to halt climate change. We need to maximize the carbon sequestration and water infiltration capacity of our farms and forests.
In Vermont, we have statutes dating back to 1992 protecting public water supplies and groundwater. Soil should also be designated as a "public good." Additionally, just as air and water quality are protected by the EPA and states are mandated and funded — soil should have the same protections and funding.
Vermont can be a leader and an example to the federal system by granting equal protection to air, water and soil — by joining other states such as California, New Mexico, Maryland and New York — in passing healthy soil legislation. Soil is life!
Originally printed in https://vtdigger.org/2022/08/23/stephen-leslie-where-has-all-the-water-gone/
This commentary is written by Stephen Leslie of Hartland, VT.
Leslie co-manages Cedar Mountain Farm and Cobb Hill Cheese, both located at Cobb Hill Co-housing in Hartland.
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