Posts

Showing posts from May, 2016

Charcoalkultur

Image
Infiltration berms belong at the public works level, but a comparable practice for us masses is hugelkultur. I attended a talk last year at the Mother Earth News fair comparing biochar to hugelkultur and discovered that hugelkultur is generally easier and less chancy than making and applying biochar. Yet, a hugelkultur bed will not be as long-lived as one with a load of biochar.

Hugelkultur is the practice of piling soil and organic material on top of a bunch of logs and sticks to form a mound (mainly on contour) which can capture runoff in order to grow plants like a super high raised bed. +paul wheaton published a DVD about it and  +Sepp Holzer put some good instructions on Paul's richsoil website.

I've been using hugelkultur to augment swales in order to reduce erosion on the back slope of my property. My previous post about infiltration berms brought me to consider hugelkultur not as an alternative to biochar, but as another opportunity to put biochar to good use. Filling …

Filling the Berm

Image
Biochar is well suited to Environmental Site Design (ESD) for stormwater management applications. Its ability to absorb up to six times its weight in water and its long drying time can be used in slowing down runoff to maintain discharge timing while increasing infiltration and evapotranspiration.

Many ESD standard practices include a gravel underlayment to promote drainage. Some of those same ESD practices do not contribute sufficiently to meeting the Channel Protection Volume (Cpv) requirement, i.e. the amount of water that is allowed to run off from a 24-hour one year storm (that is, the average of the largest 24-hour storms historically occurring in an area each year). Since Cpv is sometimes difficult to meet with ESD alone, traditional structural practices must sometimes augment the more distributed ESD practices.

One of the practices that does not contribute to Cpv is infiltration berms. These are long mounds
built orthogonally to the flow of runoff. They consist of 6" of …

Filling the Niches

Image
While our structural practices have barriers to innovation inherited from earlier versions of the Maryland Stormwater Design Manual that would impede adoption of Stockholm's approach to planting trees, the newer Environmental Site Design (ESD) practices appear to be more flexible. In Calvert County, additional flexibility is written into the stormwater ordinance that allows alternative treatment methods to be approved and used, as long as they meet the performance criteria of the Manual.

Among the ESD practices that lend themselves to inclusion of biochar in their construction are green roofs, reinforced turf, micro-bioretention, rain gardens, landscape infiltration and infiltration berms. The specifications for these practices not only offer biochar niches, but call for the added  performance that biochar so uniquely provides.


Green Roofs: the planting media spec calls for "a soil-like mixture," the base gravel layer could also be mixed with biochar, allowing longer root…

Breakthrough!

Image
Fragipan is one thing, but what about soils that are highly compacted from the top down? This is a problem common in urban landscaping, and not uncommon in parts of suburbia as well. Compaction makes it hard to start and grow plants, including trees, which serve many important functions, especially in cities. The solution is excavation and replacement of the compacted soil with a suitable growing medium.

In Stockholm, Sweden, one enlightened leader grasped the choice of replacement growing medium as an opportunity to introduce biochar into the mix whenever trees are being planted in civic landscaping projects. Biochar brings many advantages over commonly used peat moss, including its resistance to compaction. The biochar techniques used by Bjorn Embrén, head of landscaping for the city, were developed over decades and have shown stupendous results in the growth rate and survival of trees. The mixes they use include relatively little soil, but massive amounts of various grades of grave…

Biochar to Improve Soil Drainage and Save the Bay

Image
In Maryland, the Environmental Site Design (ESD) standard for water runoff is that it should mimic woods in good condition. This is difficult when impervious surfaces are being added, since the water collected and treated in stormwater management devices must then exceed what would be impeded and filtered if woodlands completelycovered the unbuilt portions of the site, i.e. the additional effectiveness required increases with the amount of impervious surface introduced. The Design Manual qualifies the standard to require that it be achieved to the Maximum Extent Practicable (MEP). This is not as big of an escape clause as it may appear, since the manual also includes a checklist that helps determine whether the design process demonstrates a sincere MEP effort.

The idea of using wooded areas as the standard for all sites is very suitable for Maryland, as a glance at Google Earth will show how very wooded our state is. Yet, rumor has it that the next update to the manual will not be so …

Storming and Norming lead to Underperforming

Image
Just from my brief exposure so far, I have concluded that the management of stormwater runoff is typical of our engineered environment in that much effort is put into the design and construction of a device, after which ensues a lifetime of neglect. It's not due to lack of regulation or even oversight, but a lack of attention by owners and a failure of governance. A well constructed stormwater pond can degrade due to erosion, poor control of vegetation, or flowpath blockages and remain that way for years, all the while earning its full TMDL credit, though performing only half as well as it should. The local authorities are loath to penalize or even notify violators of their maintenance obligations out of fear of having a negative economic impact on business. State and federal enforcers are just as remiss.

Now that Environmental Site Design has downscaled the control of stormwater to smaller devices spread throughout a new development site, it will be interesting to see whether thi…

The Grass is Always Greener when You Can Sell It

Image
When my Watershed Stewards Academy instructor blithely offered that we should stop cutting our lawn grass for the sake of better nutrient and water retention I wasn't sure if she meant stop entirely or just let it grow longer than normal. I suspect the latter, which would also support the outside-the-box idea proposed by Gene Logsdon to grow fodder crops in lieu of turf. In my case, there is only a small area remaining on my property that would lend itself to grass. I went the conservation landscaping route a year ago and my mowing duties have been minimal since.

I've been thinking of planting grass on the strip remaining in front of my Kentucky fence. I've also been trying to come up with a good guerilla gardening idea for the right-of-way that fronts the forested lot under the power lines running on the far side of my street. Aside from the black raspberry plant I stuck there last week, this just might be the best way to go.

Growing long grass will push the limit on the…

An Offer You Can't Refuse

Image
Earthworks like swales are ways to direct and slow the flow of surface water, but the low hanging fruit for livestock farmers to reduce nutrient flows into the Bay is installation of riparian buffers. That is, they should build fences to exclude grazing livestock from access to streams. If they want to save on a big fence bill and have an even more helpful result, they should consider rotational grazing. In any case, simple fences that allow wildlife to get through are an important feature.

The Best Management Practice (BMP) with the next highest potential to achieve TMDLs is conservation tillage, which includes no till and minimum till. When you include biochar as a soil amendment (not yet recognized as a BMP, but deserves that distinction), humus formation is accelerated by perhaps a factor of 10. Conservation tillage relies on humus and plants to make up for the absence of artificial soil aeration. As the years go by, such soil-building measures make it possible to reduce fertilize…

Too Big to Swale

Image
Fortunately (and wittingly) we have avoided major overflow incidents from wastewater treatment plants here in Maryland for the past several years. Easier to overlook (and we have) are nonpoint sources of water pollution, which are classified as agricultural, urban, forest, and rural, i.e. septic systems. We have become pretty wise to containing hazardous materials, but the pollutants that are choking our bays and rivers with algae are everyday elements carried in the water seeping through or running over the land. There are over 500 potential water pollutants managed in various parts of Maryland, but one ubiquitous element, nitrogen, is the major problem nutrient feeding the algae invasion of our tidal waters.
Agriculture is the largest contributor to nitrogen pollution and likely to remain so for many years. This could be because agriculture has consolidated its operations disproportionately to its proper ecological scale. Farms these days, in spite of their vast acreage, are general…

Saving the Bay with Sewage

Image
With the increase in heavy rain events (the past two weeks here, for example), the chances of having a wastewater treatment plant overflow to the watershed are growing. These incidents occur often enough for us to understand how devastating they are to the Chesapeake Bay and its tributaries. All of the efforts going into reduce nonpoint source pollution can be obviated in a day by the point source pollution of a major overflow incident. Reporting of incidents is easy to check on the state's database.

Nonetheless, the suggestions by the University of Maryland's Center for Environmental Science to reverse a decades-long trend of deteriorating conditions in Calvert County's tidal waters still emphasized nonpoint source measures, such as upgrades to septic systems and riparian buffers. That's where I come in, as perhaps the first Master Watershed Steward in Calvert County (once I complete the Watershed Steward's Academy this fall and capstone project sometime next year…

No Free Lunch

Image
Here in the 19th wealthiest county in the nation, we are without a metropolitan area unless you count the piece where I live, which is lumped together with part of St. Mary's county. We have a lot of farms in either county, so there should be no lack of wholesome food.

That being the case, what is behind the long-standing campaigns to grow and distribute free food to the "hunger community" in our area? Do such organized efforts alleviate long-term poverty? Do they invite outsiders desperate for food?

Two programs that stand out most are Farming4Hunger and End Hunger in Calvert County. Farming4Hunger appears to have the more honest appellation, since hunger might be a product of their efforts. Ending hunger is, of course, impossible and disingenuous as a campaign name.

The phrase "hunger community" is used in the annual report of Farming4Hunger and smacks of a caste system that implies separation of persons who rely on handouts for food. Joining the hunger commu…