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FAQ: How does compost protect drinking water?

Primary sources of drinking water include wells, lakes, reservoirs, and rivers.  Compost will protect drinking water sources by breaking down pollutants and reducing erosion/siltation in runoff.  Microbial activity and absorption of rainfall energy are among the mechanisms at work.

Soil microbes break down many chemicals — like petroleum products – during feeding activity, severing molecular bonds and reducing complex compounds into simpler, more benign forms.  In fact, compost is used to remediate petroleum contaminated soils at airbases, underground storage tank removal sites, highway accidents, and similar clean-up projects.

Compost’s organic matter content cushions rain or irrigation water.  When water hits the ground, that energy is disbursed, and fewer particles are dislodged.  That same organic matter also absorbs more water, resulting in less runoff.

In addition, the use of compost reduces the need for chemical input on farms, turfgrass, and in the landscape, which also helps to protect drinking water sources.

Compost is soil’s superhero

Sure, compost adds nutrients. But that might be this soil amendment’s least important function. 

Quite often, articles will mention compost as a replacement for some or all of the nutrients that might be provided to plants through applications of synthetic (man-made) fertilizers.   

That’s certainly true.  Compost delivers the macronutrients nitrogen, phosphorus, and potassium (NPK), plus a slew of plant-essential micronutrients that are missing from most synthesized fertilizer products.  Compost provides plants with a wholesome, well-rounded meal, not the nutritional equivalent of junk food. 

But what these fertilizer-focused articles rarely mention is the fact that the real value in compost use is not related to feeding plants, but to feeding soil … and soil does require a wholesome diet to function as a true soil and not a dead substrate. 

Compost feeds soil

Providing plant nutrients is just one of many soil functions.  Worms and other creatures that live in healthy soils help to physically break down food sources, then microbes take over to convert that food into plant-available form. 

Both physical and microbial conversion depend on a soil environment that can support those lifeforms.  If the soil is chronically too wet, too dry, too compacted  yada, yada  then it can’t support a healthy soil ecosystem.  That plot of ground may not be soil at all, but lifeless dirt. 

To countermand the impacts of human activity, disturbed soils require regular program of replenishment that includes organic matter and microbes.  Compost provides both.  Compost feeds soil.

Then, when it rains, soil retains that water, reducing runoff.  When runoff is reduced, so is erosion, sedimentation, and water pollution.  Because soil microbial activity also degrades pollutants, any stormwater that does run off is cleaner.  

That same microbial activity can help neutralize some soil-borne diseases, too. 

Improving plant nutrition, aiding in disease control, reducing water pollution, and retaining water are all important soil functions. 

But wait, there’s more. 

Compost as a carbon sink 

The build-up of greenhouse gases in the earth’s atmosphere is cause for concern.  As more greenhouse gases flood the atmosphere, temperatures increase. 

This rise in global temperatures influences many things, erratic and extreme weather being one of the most visible.  Subsequent climate shifts can impact people, crops, and livestock for hundreds of years. 

When used to amend soils, compost sequesters carbon.  This means the soil will act as a carbon “sink,” capturing and holding carbon in stasis – but only as long as the soil remains undisturbed.  When the soil is tilled, that carbon is released. 

Extensive use of compost for perennial crops and other long-term application(grasslands, tree farms, utility easements, etc.) can positively impact atmospheric conditions by reducing greenhouse gases.   

At the same time, the addition of compost rebuilds a topsoil layer that has been eroded or scraped away by farming, development, and other human activity.  Since topsoil loss has been identified as a significant threat to planetary health, second only to population growthits restoration is a global priority.   

At a time when nearly a third of the world’s arable land has become unproductive in just a few decades, compost really can be that superhero swooping in to save topsoil, save water, save the atmosphere, and save the planet. 

Comparing costs per gallon retained 

Soil amendment is one of the least expensive ways to collect and manage stormwater 

Manage water where it falls.” 

This sound advice is the foundation of the Milwaukee Metropolitan Sewerage District’s Regional Green Infrastructure Plana program that identified soil amendment as one of the least expensive ways to manage stormwater.  At 28 cents per gallon, improving soil is second only to native plantings in lowest cost per gallon retained. 

Green roofs?  $4.72 per gallon.  Those fancy-schmancy deep storage tunnels?  $2.42 per gallon.  At $1.59 per gallon, even pretty little rain gardens cost more than five times that of simple soil amendment. 

Milwaukee is not alone in promoting soil amendment as a first line of defense for stormwater management  For example: 

  • Denver and GreenleyColorado, require compost use for new landscaping, as does Leander, Texas. 
  • Some state Departments of Transportation (DOTs) now routinely specify compost.  A few years ago, the Texas DOT said it was the largest single market for compost in the U.S. 

In an urban environment, opportunities for soil amendment abound.  City parks, athletic fields, planters, urban lawns, highway medians and easements, foundation backfill – anywhere there’s soil, there’s opportunity for inexpensive water retention. 

Every 1 percent increase in soil organic matter (SOM) content adds an additional 16,000 gallons of water-holding capacity per acre foot.  A site managed to maintain soil organic matter at only 2 percent can hold all the water of a typical rain event (1 inch or less), which is 27,154 gallons per acre.     

In fact, at 5 percent SOM, the soil can retain the water equivalent of nearly 3-inches of rainfall.  In some regions, this equal95 percent of all storm events. 

Soil amendment may not solve all rainfall issues, especially in downtown areas.  But managing water where it falls can be the most sensible, efficient, environmentally- and economically-prudent strategy for “first line of defense” stormwater management.   

Can organic waste help green the Sahara for carbon storage?

It has been suggested devoting 5 percent of the earth’s land mass to plants bred for carbon storage could capture about half of global CO2 emissions.

That’s an area about the size of Egypt, a country that has already embarked on a program to reclaim some of the Sahara.  Project drivers are linked to food production, not climate change.  But the Land of the Pharaohs has not had an easy time of it, and some question the plan’s chances for long-term success.

Yet, as agricultural acreage declines worldwide and so many global minds focus on ways to feed a growing earth population, the Egyptian effort does beg the question:

Can reclaimed deserts store carbon and grow food?  More to the point, could composted organic waste help green up deserts like the Sahara or the Kalahari or the Sonoran?

Search the web for successful desert reclamation projects.  The use of compost is integral to all and has been referred to as “fertility priming.”

Capturing and composting organics would be the easy part. Unfortunately, there are major hurdles between barren sand and arable acres:

  • Tilling releases carbon. Unless the crops planted are perennial, some of that applied carbon will be lost.  In Egypt’s case, the goal is more annual grains like wheat and corn, perennials.  However, it should be noted, soil sampling at two of Egypt’s desert farms suggest carbon supplied from organic soil amendments will accumulate, even in oft-tilled fields.
  • While compost holds water, that water has to come from somewhere — if not rain, then rivers and aquifers or, as a last resort, desalination. But river water can be diverted by projects upstream.  Fossil aquifers, like those under northern Africa, are not replenished and will, eventually, dry up.  Desalination is still considered an expensive solution.  This means water availability will continue as the most critical factor to project success.
  • Desert soils tend to be salty, too, which creates unfavorable growing conditions. Fortunately, one permaculture specialist has reported a de-salting effect from building a living soil in the desert.

There seems to be a wealth of anecdotal material out there on desert reclamation, but not much peer-reviewed, scientific research.  Some “research” is based on calculations, not long-term field testing/studies.

In addition, the reclamation farms tend to be smaller “niche” operations — organic, biodynamic, permaculture, etc. — and not large, conventionally managed acreage.

That said, by simply looking at photos and videos, it’s obvious that desert reclamation is possible.  Whether or not it can also be profitable on a large scale remains to be seen.

But if these issues could be resolved, resulting in a clear path for resurrecting vast expanses of sandy soil, how much compost would it take to green a desert?

Most desert soils contain less than 1 percent organic matter.  To make the calculation easy, assume that number to be zero and add enough compost to boost organic matter content (OM) to the recommended 5 percent.

Based on this example,  a 1 inch application requires 135 cubic yards or 54 tons of compost per acre.  This assumes a 60 percent organic matter content, a bulk density of 800 lbs./cubic yard, and 30 percent moisture.

The author of this article about raising soil organic matter (SOM) levels says bumping SOM 1 percent “requires an additional 20,000 lbs. (10 tons) of soil organic matter or 11,600 lbs. (5.8 tons) of carbon, as soil organic matter is roughly 58 percent of carbon.”

The article further calculates stover and root mass from a no-till wheat cover crop system can only be expected to add about 0.1 percent of organic matter to soil.  Obviously, though that percentage might fluctuate a bit depending on the crop and cropping system, one of the fastest ways to build soil organic matter content is not through plants, but through compost use.

At 3.6 million square miles or about 2.3 billion acres, the Sahara is roughly the size of the United States.  It would take billions of tons to make those acres productive.

But balancing out CO2 emissions only requires a couple of plots the size of Egypt.  That’s about 500 million acres.  It sounds like a daunting task until considering there are nearly twice that many farm acres — more than 900 million as of the 2017 agricultural census — in the U.S. alone.

This is doable.  And the best news?  Nary an ounce of waste or compost needs to be hauled to Egypt.  Those 500 million acres can be divvied up and spread across the globe.  From tenders of 10,000-acre ranches to diggers of 100 sq. ft. gardens, anyone can contribute to carbon sequestration.

Of course, playing with numbers is just that — play.   A tremendous amount of effort, plus a megadose of dollars, would be required to convert all world organics to compost.  But rough numbers and real-world economics suggest sequestering carbon through compost use is possible.  (View the SlideShare title: Compost to the Rescue)

And as the World Bank expects the global waste stream to grow by 70 percent by 2050, it sounds like there will be plenty of organics available to get the job done.

Bottom line:  We have the know-how.  We have the technology.  We have the organics.  Costs to produce compost are competitive with landfilling and WTE/incineration.  And whether existing farmland, greenspace, or desert, whether Africa, Asia, or the Americas, we have the acreage needed to clear the air.  The only thing missing? The will to do so.

Transplanting can be a tricky business.  Whether moving from a greenhouse or a personal garden, plants do not care for the experience.  And transplanting can sometimes trigger a disastrous response from the plant.

When the stress or damage is too much for the plant, transplant shock may result.  The plant either wins the struggle to adapt to its new home or dies. Different species and varieties of plants can handle transplanting better than others, but the threat is always present.

Usually, transplant shock can be caused by a failure to allow the plant enough time to acclimate to a new temperature. This is especially true if the plant has been raised in a protected condition such as a greenhouse. Another cause is when the roots of the plant have disturbed too much during transplant. Other factors that can make a difference include the weather conditions during the process, and the treatment the plant receives shortly after transplant.

Compost is an effective way to combat transplant shock, as the mechanisms of compost work well to help make the process go smoothly. Unlike fertilizers, compost requires fewer applications and will last longer keeping the soil healthy. The additional nutrients will also help the plant acclimate to its new home and lower stress levels. Reducing the amount of stress a plant experiences is paramount to a good transplant.

Immature/unstable composts can increase difficulties for transplants, so be sure to choose a quality, stable compost product like McGill SoilBuilder, especially if planting under plastic.

Amending soil with compost builds soil organic matter (SOM) and replenishes soil microbial populations.  Both help all types of plants –from vegetables to trees — to not only survive the “shocking” indignities of transplanting, but thrive throughout the season.

Read more about transplant shock and compost:

http://gardening.yardener.com/Compost-And-Transplants

http://www.wikihow.com/Use-Your-Compost

http://www.bartlett.com/resources/Transplant_Shock-http://www.wikihow.com/Use-Your-CompostPart_1.pdf

 

Read it.  Amended attitude: a new commitment to soil health using compost, written by Gary Gittere and recently published by SportsTurf Magazine.

Douglas Wilder Middle School field gets ready for compost in 2010.

Douglas Wilder Middle School field gets ready for compost in 2010.

A few years back, Henrico County, Virginia, decided to start using compost on its fields and lawns.

Because of this decision, the county sees improved endurance to the wear and tear of their fields. They’ve also been able to save time and money in maintenance.

Two employees of the Recreation and Parks Department in Henrico spoke about the responsibilities of their jobs. Jason Melton, Turf Maintenance Superintendent, and Blake Phillips, Sports Field/Recreational District Foreman, have seen vast improvement. They credit the use of compost.

The men are responsible for all irrigated turf in the county. This includes about 130 acres consisting of the lawns of rec centers and historic homes, as well as athletic fields.

“Softball, baseball, soccer, multi-use fields, lacrosse, one croquet court, and one stadium baseball field where we host special events,” Melton listed. “In the past, we’ve hosted the Babe Ruth 13-year-old World Series and plan on hosting this event again in 2014. For the past several years, we have also been hosting the Triple Crown United States Baseball Championships.”

Henrico started using organics 4-5 years ago based on research conducted by Dr. Andrew McNitt at Penn State University.

“The first field renovated with compost, I think we used a 2- inch depth over the entire 70,000 sq. ft. soccer field, tilled to a depth of 5-6 inches, and that was SoilBuilder,” Melton recalled. “We sprigged this field and results were amazing. Since then, using compost has been standard for our renovations and new construction.”

Douglas Wilder Middle School field two years later after compost application.

Douglas Wilder Middle School field two years later after compost application.

Phillips explained the process. “Sprigging is the process of establishing warm season grasses using the stolons and rhizomes (the vegetative part of the plant).  We normally sprig at a rate of 600 – 800 bushels per acre.”

Melton spoke about the results they saw in soil organic matter (SOM) for one of the fields they tested. “Our native soils range anywhere from 3-5 percent.  After blending 2 inches of compost into the softball fields at Glen Allen, we saw an increase in organic matter ranging from 3 to 5 percent.”

Since many of the fields they oversee are used for recreation, the wear and tear can be tough.  But  through the use of compost, the field holds up, Henrico reports. The results go beyond improvement of the soil.

Prior to compost use, the County Youth Football Field required a fertilizer application four times a year.  It cost $520 each time for fertilizer. Now, thanks to compost use, the maintenance team says savings for this particular field  are $1,240 for material only.  That doesn’t count time, labor, and fuel.

Jason Melton is the Turf Maintenance Superintendent for Henrico County. He was graduated from Virginia Tech in 1998 with a degree in Forestry and Wildlife.

Blake Phillips is Henrico County’s Sports Field – Recreational District Foreman. He was graduated from Longwood University with a Business Management degree. His father is a sod farmer in Southampton County, VA.   Phillips worked for a turf company during his high school years and summers during college.

McGill SoilBuilder Premium Compost is pleased to announce its participation in the U.S. Composting Council’s Million Tomato campaign to help boost soil health and growing power in community gardens.  Learn more about this national program at http://buy-compost.com/ or contact McGill compost sales at 910-532-2539.

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