Monday, March 27, 2017

Potential Heavy Metal Contamination from Growing Vegetable in Vehicle Tires

René Pierre (right, red cap) from Demòn, in the mountains of Bayonnais, Gonaïves is leaning on a vegetable tire bench that he re-built and re-planted after Hurricane Matthew knocked his tire garden down, along with important bits of his family's home.
Does using old tires for producing vegetable represent the risk of contamination by heavy metals?

Over the years, people have raised the concern with me that growing vegetables in old tires can lead to heavy metal contamination of the plants, and therefore would represent a health risk to the very people we are trying to help. I have struggled to get clear information about the risks, which has included an ongoing dialogue with several people related to Educational Concerns for Hunger Organization [ECHO].

In January 2016, ECHO published an article in their ECHO Development Notes titled "Tire Contaminants from a Container Gardening Perspective" which reviewed a number of articles, particularly one from the United Kingdom and one from Nepal. The one from the UK, "Environmental Health Implications of Heavy Metal Pollution from Car Tires" by J.M. Horner (1996) cannot be downloaded online but the abstract can be found at [Environmental Health Implications of Heavy Metal Pollution from Car Tires"]  and a request can be made for the full article.

The article from Nepal, "Studies and Determination of Heavy Metals in Waste Tyres and Their Impacts on the Environment" by P.R. Shakya et al (2006) is downloadable from the following link [Nepal Tire Contaminants Study]

You can download the ECHO article directly from a Google search using the title, "Tire Contaminants from a Container Gardening Perspective." Look for the [PDF] initials right before the title. Other avenues for the article require you to be a member of the ECHO Community (which is free and an excellent thing to be).

I have a whole lot of other downloaded articles related to contamination, some of which I have worked through somewhat thoroughly, others that I just read the abstract. There is a study from the 1990's commissioned by the Ontario government that tested the effects of tires soaking in fresh water. The researchers generally found very little toxicity to trout fingerlings [Ontario study of Aquatic Environments]. I found another study today that also had a focus on the aquatic effect of tires, but with a more negative result, "Rubber Tire Leachates in the Aquatic Environment" by Joyce. J. Evans in Reviews of Environmental Contamination and Toxicology. The following site will sell you the chapter for $29 and the whole book for $99. You can look at the first couple of pages for free: [Rubber Tire Leachates in the Aquatic Environment]. The difference between the two seems to be that the Ontario study looked at the effect of whole tires on aquatic environments in which the whole tires are submersed. The second study looks at what happens when the rubber is ground up and water leaches through the concentrated, ground up tire and then flows into the local aquatic system.

The two most recent studies that I have looked at a little more thoroughly both come from Sweden. "Metal Emissions from Brake Linings and Tires: Case Studies of Stockholm, Sweden 1995/1998 and 2005" by David S.T. Hjortenkrans (2007). You can download it at [Swedish Article]. The title looks complicated but the basic information about concentrations is simple and clear and found on page 5227, 2nd paragraph under the tables.  I just found the 2nd Swedish article today. The title is great, "When the Rubber Meets the Road: Ecotoxicological Hazard and Risk Assessment of Tire Wear Particles" by Anna Wik (2008) [When the Rubber Meets the Road].

If I told you I had read all of these articles, even just the ones I have downloaded and  printed out, from front to back, I hope you would not believe me. If I told you that I have understood at least three-quarters of what I have read, you might believe me, but I would still be lying. I guess I've gotten maybe half of it all at best. This is NOT my area of expertise. Chemistry, and especially Biological Chemistry is fundamental to understanding soils and growing plants. I think I am solid enough when it comes to understanding pH, Cation Exchange Capacity and at least the basics of the whole Nitrogen:Carbon relationship. But tires are complex. They are not just natural rubber. In fact, the excerpt from the Rubber Tire Leachates study includes the observation that tires today are mostly made of synthetic substances rather than from natural rubber. The Swedish Doctoral Thesis ("When the Rubber Meets the Road"), lists the following materials for the tire tread: synthetic and natural rubbers (40-60%), Carbon black and silica (20-35%), Mineral oils (15-20%), Sulphur (1%), Zinc oxide (1.5%). There is something like 2% of three or four other types of substances as well.

Here's what I think I do understand.

None of these articles are actually looking at the way we use tires.

In the ECHO arcticle, Ben Fisher and other ECHO staff members had to struggle with the same thing. They had to extrapolate from the information provided, applying it to the vegetable tire scenario as best they could, without knowing exactly how everything fits within a very different context.

The article from the UK used fragments of tire leached with solutions with a pH of 2.5.  That study was simulating the conditions of a pile of waste tires exposed to acid rain.

The Nepal study actually burned the tire samples and measured the heavy metals in the ash. That simulated very well what happens in Nepal where many families use cut up tires as a fuel source for warmth.

"When the Rubber Meets the Road" looked at the bits that come off the tires and contaminate the environment. Like the Nepal study, they measured the total concentration of heavy metals in the tire treads. I like the fact that they look at the treads, but we are not rolling our tires on the ground to grow vegetables.

The Ontario study was similar to using tires for vegetables in the sense that they looked at the impact on the whole, un-fragmented tire. It was also similar in the sense that they looked at the direct impact of potential leachates from water flowing over the intact tires on living beings--trout fingerlings instead of spinach, carrots, peppers and tomatoes. This study models our situation more closely than the others because it measures real time, direct impact on living things, while the others destroy the tires in ways that do not in any way represent how we use the tires.

Perhaps most convincingly for me, the absolute amounts of heavy metals potentially in the tires is actually very very low.


I understand that there are four heavy metals that are of concern which have been found in tires. They are lead, cadmium, chromium and zinc.

The following examples are given in grams. A gram is smallish unit of mass, so obviously fractions of grams are even less. There are about 450 grams in one pound. There are about 28 g in one ounce. Medicines are almost always measure in milligrams, which is 1/1000th of a gram. PPM  stands for "parts per million." What that means is that 1 ppm is  1/1,000,000 (one one-millionth) of a gram of heavy metal for each gram of tire material.


In all of the studies, the lead that was found in the tires did not come from the manufacturing. It accumulates on the tires as the roll along the road, picking it up from other sources. Brake linings, for example, have a significant amount of lead.

The UK study found concentrations of between 8.1 and 22.33 ppm (parts per million) lead in the liquid leached from the tire fragments.

On average, a truck tire weighs about 40 pounds, or about 18 kg. Using the higher concentration, this gives a total of  0.40 g potential lead that would be leached out of a whole tire.

The Swedish study actually found less lead in their tires. They got a concentration of 1.1 ppm, the equivalent of a total of 0.0198 g in the whole pickup tire. Again, the Swedish study focused on the tire tread because they wanted to know what was coming off the tire and dispersing as a contaminant into the environment.

Note: Because different studies examined different parts of the tire, I am assuming that the concentration of heavy metals remains constant for the whole tire in order to try and get a sense of the range of the heavy metals in a whole tire.

The UK study found up to 3 ppm of cadmium, the equivalent of 0.054 g per large pickup-sized tire. The Swedish study found 1.1 ppm of cadmium, the equivalent of 0.040 gram in the whole tire.

The UK study did not look at chromium. In the Swedish study, they found 8.6 ppm in the tread, which extrapolates to 0.155 g per tire, if concentrations remain constant for the whole tire.

(Ben Fisher in the ECHO article notes that at  Redeemer University College they tested a tire sample and found 0.9 ppm cadmium, about the same as the Swedish study).

Zinc is a nutrient for both plants and animals, but in excessive concentrations, it can cause damage to both. If the soil is highly contaminated with zinc, it will probably kill the plants. On the other hand, if humans cease to be exposed to or to consume excessive Zinc, the symptoms will generally disappear, according to the information presented by Ben Fisher in the ECHO article.

In the UK study, they found as much as 6012 ppm, the equivalent of  108.2 g in an entire truck tire. The Swedish study found as much as 12,000 ppm, the equivalent of 206 g in the whole tire.


When we create vegetable tire gardens in the Yard Garden program, or in my home yard, for example, we are not shredding the tires, we are not completely submerging them in water and we are not exposing them to highly acidic conditions. We do cut off one sidewall, but the soil is not exposed in any way to that area that we slice. We also turn the tires inside out, so the soil is exposed to the tire tread. In this sense, the numbers from the Swedish study are the most applicable. On the other hand, once the tires are planted, the rubber in our tires is no longer "hitting the road" so we are not contaminating our soil with bits of tire that rub off from friction.

One of the article notes that biological action will continue to degrade the tire. Our goal is to create soils that are extremely biologically active, so this type of degradation will continue to occur inside along the tire tread, but it will occur without the aid of constant saturation with water, abrasion by wind, exposure to ultraviolet rays, or mechanical friction. The outside of the tire will continue to be exposed to sun and wind and that will result in certain levels of degradation but should not effect the soil inside the tire for many years.

So, given that these articles suggest that the TOTAL amount of lead, cadmium and chromium is less than one gram in the whole tire each, AND that those fractions of grams are not generally exposed to being released from the rubber, it seems abundantly clear that these heavy metals do not pose any serious health risk. Zinc, although present in much higher amounts, is also highly unlikely to pose any real risk because 1) the zinc is ALSO bound up into the tread and if it leaches or degrades out, it is likely that it will do so at relatively slow rates; 2) the zinc may kill the plants rather than render them poisonous for us and 3) increased intake of zinc by families, up to a point, could potentially have positive health effects.

In terms of the cocktail of other chemicals that make up a tire, they are also a potential concern. A brief e-mail conversation that I had with the Dr. Edward Berkalaar at Redeemer University College suggested that some hydrocarbons in tires can be taken up by plant roots. On the other hand, a note in the ECHO article cited information demonstrating that potentially toxic hydrocarbons would be a high risk for contamination only at a high pH. Ben Fisher does not mention the cut-off pH that the article thought the hydrocarbons would become more active, but "high" in terms of pH would normally start at 8.0 and above.

The Ontario stud that I liked the best of all of them, found essentially that old tires soaked in water did not effect trout fingerlings in any measurable way; however they did find that new tires soaked in water could cause significant mortality. They got to where they could pinpoint that the substance associated with the mortality was one of the hydrocarbons--one or more of the "mineral oils" mentioned above.

Tires on the whole pose serious environmental risks. Disposal of them as trash where hundreds and even thousands are dumped in one relatively small area clearly has the potential to cause a serious environmental disaster. Grinding the tires up and then exposing them to sun and rain understandably creates conditions  for significant heavy metal contamination as the small particles degrade even more. There are probably many additional ways to store or recycle tires badly.

Based on the information currently available, using a tire essentially intact for growing vegetables is not a risky way to use old tires.

The article from Echo Development Notes proposes some best practices and I believe they are essentially correct. Here is my own version of those best practices:

1) Choose tires that can be turned inside out so that the soil medium is exposed to the tread. This is the part of the tire that has been studied the most, so any additional information that comes out will probably be most applicable. To test a tire, lean lightly on the top of a tire standing straight up. If it bulges in easily, it should turn inside out easily.

Turning the tire inside out also assures that water will flow through the soil, rather than puddling at the bottom of the soil profile, full of potential leachates.

2) Avoid tires that are retreads, or that have any kind of significant damage to the tread or the sidewalls. If the rubber has worn in any part of the tread to the point that wires are sticking out, do NOT use the tire for growing vegetables. This is especially important for tires made in China. In the Nepal study, the brand tested from China had much higher lead concentrations.

Also, if possible, choose tires that are less than 10 years old. Tires in the States have the date they were manufactured printed on very small print. Good luck with that part.

3) Wash the tire before using it to get any accumulated hydrocarbons and carbon black out and off the treads. A couple of good rains should also do the job, once the tire is prepared and turned inside out so that the water flows through the tire and does not puddle.

4) Use a soil mix high in organic matter. This is obviously best for the health of the plant. Also, the carbon will bind readily with any offensive metals. If you have the means to measure the pH, make sure it hovers between 6.0 and 6.5. This is best for most vegetables and it seems to avoid the extremes that could promote either the leaching of heavy metals or the activation of the hydrocarbons. High organic matter will tend to keep the pH within this range.

5) Include biochar in your soil mix. We have seen that biochar helps increase vegetable production AND it also helps bind any offensive metals. Biochar also helps create a sponge texture in the soil mix which will keep your moisture supply more consistent and your roots happier and healthier.

6) Use 4-6" of mulch around the plants. It conserves moister, reduces soil temperature and provides a slow and steady supply of nutrients. I mix our kitchen waste with sawdust from a local furniture maker and periodically apply this half to three-quarters rotted mix as a thick mulch to the tires. In my experience, this helps maintain and even increase the organic matter in the soil over time, resulting in healthier and more productive vegetables and flowers.

6) Plant anything you want in the tires. Ben Fisher notes in the ECHO article that root crops are most likely to pick up heavy metals, fruits such as tomatoes or peppers are the least likely and leaf-producing crops are intermediate. But really, we're talking about minuscule amounts of metals spread out over a pretty big space. It really is not an issue, especially if you have followed the ideas mentioned above. In terms of the zinc, here is an abstract of a study that looked at the sensitivity of four vegetables to zinc concentration: [Zince Sensitivity]. Let me know in the comments if you find out more.

7) If you have the resources, paint the tires on the outside. It adds to the aesthetics and is a fun part of making a tire garden with young people. It will also help protect the outer part of the tire from degradation from the sun. It will also reduce temperatures for the layer of soil just inside the tire wall.

PLEASE SHARE ANY IDEAS OR OBSERVATIONS. I have been breaking my brain over this contamination issue for a long time. Conversations with Martin Price at ECHO and others kept me fully in the game of creating tire gardens, not to mention the beautiful production I've seen again and again in other yards and in our own. But I feel like I have finally got things really clear. I think I have read Ben Fisher's EDN article at least a dozen times, but finally today, with all of the other information I've digested, I really feel like I have a handle on it all.

Tires are by far the best option for container gardening. They are cheap, durable and can be transported long distances on the backs of pack animals.

Here is a link to Youtube videos that demonstrate how to get started with a vegetable tire garden: How to start a tire garden--MPP, Haiti

Sack gardens are also an incredible idea, but that is another blog.

Jenny, Keila, Annika and my tire garden in Barahona. We had green peppers, tomatoes, Okinawa spinach, basil, garlic chives and eggplants, not to mention the flowers. May 2015.

Tuesday, March 21, 2017

Hurricane Matthew--How you can help the farmers of Haiti

"Hurricane Matthew destroyed their crops in the middle of the growing season. And they will need the most help NOW, as the new growing season begins."

 October 4th through the 6th, Hurricane Matthew hit Haiti head on.  
 It was the worst natural-human caused disaster that Haiti has suffered since the earthquake of January 12th, 2010. Hurricane Matthew's greatest impact was in Haiti's southwestern peninsula. Grand Anse, including the capital of Jeremie, was devastated. The report on the hurricane's impact on Haiti from  Wikipedia [Effects of Hurricane Matthew in Haiti ] suggests that virtually every tree in Grand Anse was knocked down. I avoided looking at many photos, but I did read a few accounts from folks on the ground who confirmed that that land looked like it had been bombed. Cindy Corell, one our colleagues in World Mission shared some of what she saw in her blog from November 2016 [Cindy Corell: November 2016]. All crops were lost and at least half of the farm animals. The departments of Sur and Nippe were also exceptionally hard hit, as was the northwestern peninsula. The first map below demarcates the wind levels suffered. The second gives actual rainfall. Links in the captions lead to the original sources.

From twenty years now of experience with tropical storms and hurricanes, I know that rainfall causes much more widespread damage than the wind in mountainous terrain such as Haiti and the Dominican Republic, although with winds of 145 mph in the southwest, the winds that smacked southwester Haiti certainly were the initial source of the utter devastation. After Hurricane Matthew had passed, however, rains continued to fall for three weeks throughout the country; they fell most heavily in the south and the northeast. In part due to the continued heavy rains, a new round of cholera has added to the misery [A Photographer's Journey Into Haiti’s Cholera Crisis].

Overview of track and wind forces

This image shows the amount of rainfall dropped by Hurricane Matthew over the life and track of the storm. IMERG real time data covering the period from Sept. 28 through Oct. 10, 2016 show rainfall from Hurricane Matthew before and after its interaction with a frontal boundary. Matthew caused extreme rainfall in North Carolina resulting in over 20 inches (508 mm) of rain. Credits: NASA/JAXA, Hal Pierce

The Haiti Mission Network of the Presbyterian Church (USA) is working to link people throughout the denomination engaged with Haiti. You can check out the Facebook page:

Haiti Mission Network-Presbyterian Church (USA)

If you want to check out the posts most pertinent to the situation with Hurricane Matthew, you will need to select (upper left hand corner) "2016", rather than "Recent." October and November have the most posts.

This past March 12th, 13th and 14th, we had a major Mission Network Get Together in Asheville, North Carolina. Buzz Durham from outside of Asheville coordinated  a host of volunteers to make it happen. His congregation, Grace Covenant Presbyterian Church was one of the main hosts. Our colleague Jo Ella Holman worked with Buzz, Cindy Corell, and me to think through some of the logistics. Cindy and I, together with Cindy's Haitian colleague from FONDAMA, Fabienn Jean participated in the event, which included between 35 and 40 people representing more than a dozen mission engagements. Our focus was how can we be effective and respectful partners of the work that Haitians are already doing.

Cindy Corell [Mission Connections] has some excellent posts on Facebook: Cindy Corell: Facebook

I had the pleasure of translating for Fabienne Jean as she described to the participants how FONDAMA is responding to the crisis in the south as well as other areas hit by the subsequent flooding.

I visited FONDAMA's office in December during a quick family trip and saw the initial stockpile of vegetable seeds that they had purchased to send out to the farmer organizations working in departments of Haiti most affected by Matthew.  Most of these seeds were sent to Grand Anse, Nippe, Sur and L'Ouest, as well as the Nordest. They had cabbage, lettuce, tropical spinach (amaranth), okra and black-eyed peas, all crops that can be ready to eat and to sell in less than three months. The spinach can be ready for the table in 30 days or less from the planting date.
Farmers in Haiti are durable people. Knock their house down, they will find a way to put it back up. But Hurricane Matthew destroyed their crops in the middle of the growing season. And they will need the most help NOW, as the new growing season begins. As many of you know, FONDAMA is a network of grassroots farmer organizations led by people who understand their constituency--because they are farmers themselves.

Their focus in December were vegetable seeds--fast growing food. Now, Fabienne explained, they are working with Presbyterian Disaster Assistance to provide seeds for staple crops--beans, corn, pigeon pea. Along with the seeds they will train trainers in agroecological techniques that can help farmers recuperate their land, even as they grow the food that will sustain their families. The trainers, Fabienne explained, come from throughout the remote rural areas of the mountainous Southwest. They live near the people with whom they will be working. In each community they will also establish seed banks, where farmers will repay their seeds, plus interest. The goal is for these seed banks to serve as buffers, to create resilience, so that farmers have greater security when the time to plant comes.

Fabienne explained that the work also include providing simple systems for treating water, the main source of cholera infections.

If they can find the funds, the leaders of FONDAMA hope to include a second stage to this program, helping families recover their farm animals, especially the goats and pigs.

Thank you to all of you who have already donated through PDA and other funding sites. Thank you also for your prayers and your concern. If you or your congregation feel called to donate now, PDA is still a great way to go.

Funds can be sent to PDA, ( which is working hand in hand with Fondama Haiti to help provide seeds and tools to the mountain farmers of Haiti.

 It is unfortunate that my first Haiti blog after so long is about a disaster. But it was probably the burning need to do something that brought me back here again, finally.

In my next blog, I want to share stories from the communities where Herve Delisma and I worked from April 2012 through April 2016 with yard gardens. MPP (Farmer Movement of Papaye) was able to send Herve and a small team to each of the three farmer organizations to visit with people who were also hit by the hurricane. The winds, even though much less, tore off a lot of roofs and destroyed homes throughout the mountains of Léogâne, Verettes and Bayonnais. Crops were lost as were the farm animals. Many of the yard gardens, however, survived.

But that is the next story!

P.S. The mission of FONDAMA and all of the Joining Hands organizations throughout the world is to address root causes of hunger. In Haiti, in addition to responding compassionately to the situation in the south, FONDAMA is gearing up to confront large corporations and the Haitian government itself as these entities move to grab land from small holder farmers for the creations of industrial parks, mega-plantations of bananas and other export crops, or for mining gold and other minerals.

Monday, September 21, 2015

Moringa oleifera--an NPR report

Here is an NPR report online about moringa.

"One doesn't need to do very much to prove that if you are hungry or nutritionally replete, then eating moringa as a source of vegetable protein in a varied diet is a good thing to do. We're beyond the need to prove that."

Jed Fahey, a nutritional biochemist at the Johns Hopkins Bloomberg School of Public Health who has been studying the plant for 20 years.

 Thank you, Gordon French, for the link.

NPR: Moringa
NPR: Moringa

Tesilia Desilus, with moringa leaf powder she produced at her home in Salas, Dofine (Verettes)  

Tuesday, September 8, 2015

Making Vegetable Tires: Some Links

Here is a link to a great blog on how to choose a tire that can be turned, and how to turn it.

Making a Tire Planter:
Making a Tire Planter

The best advice is at the end:

"Practice arching one eyebrow and staring haughtily back at the ignorant critics."

Also, here is the link again to the series of videos created by UUSC, Unitarian Universalist Social Committee:

How to Build Tire Gardens
How to Build Tire Gardens

I think I shared this link already, but just in case.

Friday, May 15, 2015

Follow up to Ferrocement cisterns in the mountains of Verettes

A quick follow up to the original blog. I spoke with Andre yesterday, Thursday May 14th. Ricot Joachim and Exode returned to Dofine this week to finish the project. They put the top on the cistern at MRPST's school/center, then went up into the mountains, and according to Andre, had already finished the second cistern and were headed toward the third. They are working with the same MRSPT masons, hopefully letting them do more and more of the work.

Andre had worked with Herve to get him up the mountain so that he can take photos and continue documenting the work.

Three or four days after the original workshop ended, Herve, Lucien and I sat together and wrote down all of the steps, and all of the measurements, for building a cistern. Hopefully I can get that document put together with the photos to create a manual that MPP can use in their training workshops.

Ferrocement workshop in the mountains of Verettes

Starting the workshop. We held the theoretical sessions outside the center, because primary school was in session. Participants are: civil engineer, Junior Lapaix (facing, green and grey polo shirt) in Dofine, a beautiful, fertile zone in the mountains of Verettes (Artibonite Department). Junior is sharing technical information about cement and cement construction with a group of Haitian masons from the farmer organization, MRPST. The masons are, from left to right, Fanord Toicius, Renaud Segné, Samuel Antoine,  and Clermius Pierre-Louis. Also participating were (continuing from left to right): Exode Pierre (red & white striped shirt), a mason from the farmer organization MPP (Peasant Movement of Papaye); Mark Hare, PCUSA Mission Co-worker; and Lucien Joseph, a member of MPP and part of the team helping carry out the activities of the MPP-FONDAMA Yard Garden Program. The workshop was held at MRPST's primary school and training center in Dofine from Tuesday, April 21st through Friday, April 24th. Coordinates for the center are: N 19.00151º, W 72.48059º. Photo by Herve Delisma. Note the Toyota Landcruiser enclosed truck in the background. It was purchased for the MPP-FONDMA Yard Garden Project with funds from the Presbyterian Hunger Program.
On Monday, April 20th, we arrived at MRPST's center, at the end of a long, rough road, well after dark. We were an interesting crew. I am from Ohio, but I have been a Mission Worker with PC(USA) for over fifteen years, working with rural families in Nicaragua and, for the last eleven years, in Haiti, with the Peasant Movement of Papaye (MPP, for its initials in Haitian Creole).

Junior Lapaix, born and raised in Haiti's Central Plateau, is a civil engineer who was in his last year of the University in 2010 when the earthquake brought the University crashing down. Since the earthquake he has been a member of MPP's technical team, helping execute the organizations' water projects that are part of the organization's program to make safe water available to rural communities.

Carel Sainfinis, our driver, was originally from Port au Prince. He and his wife lost their two-story house in the earthquake of 2010 and nearly all of their other material goods. That led them as refugees to MPP in the Central Plateau. Carel eventually become a driver for the organization and last year the family settled in a home of their own, in one of MPP's five eco-villages, built with funds from Presbyterian Disaster Agency (MPP Ecovillages). Carel frequently drives the Toyota Landcruiser for me, as part of my work coordinating the MPP-FONDAMA Yard Garden program. The work of the Yard Garden takes Herve, myself and our ad hoc team members all over the mountains of Verettes, Gonaïves and Léogâne.

Herve Delisma is originally from Cité Soleil, in Port au Prince, but as a teenager, his mother sent him to live with his sister in the city of Hinche to get him away from the Cité Soleil gangs. Now he lives in an even more rural setting on the outside of Hinche near the community of Papaye. Herve and his wife, Kekèt, and their two children do a good job of producing food in their yard--when it rains.Herve also works as my assistant in the PDA-funded Yard Garden Program.

Lucien Joseph is a young man who left high school due to a vision problem that can't be corrected, with lenses. He was apprenticed to a furniture maker, but now works part time with his brothers in Port (au Prince). Lucien always returns home during the rainy season to plant and care for his gardens, and to work with Herve and me when we need him. With a beautiful plantation of moringa at his parents' home outside of Papye, Lucien is an effective promoter of yard garden systems.

Ricot Joachim is the head of MPP's security team, but he is also a farmer and a mason. He learned to build ferrocement cisterns (Ferrocement) when MPP selected him to participate in a series of workshops led by MPP agronomists (Agronomist) and masons; these instructors received their training in a permaculture (Permaculture) program in Brazil sponsored by European donor organizations.

Like Ricot, Exode Pierre is also a farmer and a mason, and a member of MPP. He has been Ricot's assistant in a series of ferrous-cement cistern projects throughout the Central Plateau. When I asked them how many cisterns they've done together, Ricot said "Huh. I can't even begin to count."

MRPST, the organization that welcomed us late in the evening on April 20th, was founded in 1998. MRPST (Peasants Without Land Revindicating for their Rights--Mouvman Revandikasyon Peyizan San Tè) began with half a dozen friends meeting clandestinely at the home of George Ulus, next door to the school where we held the workshop. The goal of the  movement was to take back land that had been, in one way or another, stolen from them, their parents and their grandparents by a man named Marc Etienne. Through a local farmer who served as his agent, this landowner made a lot of money from the land he appropriated by renting it back to the original owners. Cindy Corell, the companionship facilitator in Haiti for Joining Hands (Cindy Corell) is collecting stories of MRPST's struggles which have, all in all, been successful thus far.

Since 2012, Herve, Lucien and I have been working with the leaders of MRPST, helping them establish their own yard garden program. After a series of ups and downs, this year the organization's program has really begun to take off.

Now the leaders of MRPST had also been blessed to receive funds from the Hunger Program of the Presbytery of the James in eastern Virginia and some addition funds from the Water for Life Campaign, based in Portland, Oregon. In total, the organization received about $8,000 to build three cisterns, each with a capacity for about 3,500 gallons of  rainwater. The first was to be built at the organization's center as part of a workshop that would introduce the four MRPST masons in both the theoretical concepts and their practical application. Junior was responsible for the theoretical and Ricot, with the help of his assistant, Exode was responsible for the practical. Herve, Lucien and I were along to learn as much as we could, and to document. We were also able to direct funds from the Yard Garden program to help pay for the food for the workshop.

After three days of intense work, starting around 7:00 AM each day and finishing between 4:00 and 5:00 PM, the workshop came to a successful conclusion. The icing on the cake was the arrival of Valdir França and Jo Ella Holman from PC(USA) World Mission. Valdir França is the area coordinator for Latin America and Jo Ella Holman is the regional liaison for the Caribbean. Cind Corell, the companionship facilitator for Joining Hands, had coordinated their visit as part of sharing with them an on-the-ground look at her work coordinating the Joining Hands ministry with FONDAMA. FONDAMA is a network of  Haitian grassroots organizations working to renew Haiti's environment and establish food sovereignty. MRPST is a member of FONDAMA through their relationship with MPP.

Countless personal stories that brought a dozen and a half or so individuals together, supported by the joint efforts of half a dozen organizations, projects and agencies (MPP, MPP's Techncial Team, MRPST, FONDAMA PDA, PHP, World Missions, Presbytery of the James). If any of us had tried to intentionally bring all of these pieces together to make this workshop happen, we would have been called fools.

We would have been fools.

"For the foolishness of God is wiser than human wisdom, and the weakness of God is stronger than human strength."

"My message and my preaching were not with wise and persuasive words, but with a demonstration of the Spirit’s power, so that your faith might not rest on human wisdom, but on God’s power."
I Corinthians 1: 25, 2: 4-5 (NIV)


Now for the pictures.
(Photos by Herve Delisma and Mark Hare, unless otherwise indicated)

Most of the tools you need for the cistern. From left to right: Shovel and pick and an iron bar for digging the base of the cistern. The bar is for cracking rocks or hard pan. Two sheets of aluminum with handles for holding the mortar onto the frame and a cement trowel. A wood "float," used as a palette to hold the mortar you are adding to the structure, and to work the final layer that seals the cistern. Two sieves. The one above to get a sand that is slightly coarser--for the structure. The one below for finer sand that is used to seal the cistern. A sledge to help with the rocks when we were digging the base. Pliers for working with the binding wire. Bolt cutters (behind) to cut the metal framework. A hacksaw for whatever the bolt cutters can't take out.

Ricot Joachim, in the read shirt, starting to pick the soil for the base. After choosing a site close to the school/center, Ricot measured a diameter of 3.5 m and put a stake in the middle. Then he tied a string to the center stake, measure 1.75 m along the string, then tied another stake which he then dragged all the way around the center stake to mark the base. Ricot was an excellent teacher for the practical component of the workshop. He would work with the team until we understood what we were doing, then he would step back and watch, to see if we were really doing it correctly.

Renaud, from LaCroix, picking out the mark that Ricot had made, all around the center stake.

Laying a base of gravel in the base. We dug out something like 5 cm at the shallow end. Bondyebon is to the left, Exode to the right.

Ricot and Samuel (green shirt) with the pipe that will feed the water from the cistern into a faucet on the lower end. Fanord is to the left.

If I couldn't find something else to do, I made myself useful by dipping water from the canal that runs by the school and filtering it through a t-shirt into one of the two plastic barrels. Carel the driver helped me.

Pouring the base. The concrete base was 2 parts cement, 4 parts coarse sand and 6 parts gravel. You can see the 2" pipe that leads from the lower end of the base underneath and out.

Preparing the mesh for the base. Ricot cut two pieces, approximately 5 meters long. The mesh is made of 1/4" pieces of iron reinforcement bar welded together into a framework of 15 X 15 cm squares.

Then Ricot overlapped the two pieces and tied them together with binding wire (#16)

Then Ricot repeated approximately the same process he used to line out the hole. He measured a diameter of 3.5 m in every direction, then put a stake in the ground in the center. With a string that measured 1.75 cm, he walked around the center stake, but instead of using another stake, he borrowed a black Sharpie marker from me to mark where the mesh would be cut. As Exode continued to mark, Ricot began cutting with the bolt cutters.

When they were finished with the mesh, they laid it on top of the concrete base. The base was already mostly dry, so it was not embedded into the concrete. You can see they lbits of rebar, about 5 cm long, sticking up.

The next piece was for the sides. Ricot had us roll out the iron rebar mesh, 11.2 m long (the rolls of mesh are about 2 m wide).

On top of this, they lay one width of good quality chicken wire, also 11.2 m long. You can see that the width of the chicken wire was about 45 cm less wide than the rebar mesh.

Then they wove the two materials together

With almost everyone helping, they stood the framework up and walked it down and around the base, forming a nearly perfect round cage.

Then they tied the framework to the rebar mesh base. In four our five places, they also put in stakes and tied the stakes to the framework with binding wire, to help assure the framework would keep its shape. We finished all of this around 1 PM on Wednesday, April 22nd.
Early in the morning, Thursday April 23rd. Mixing the mortar for the first layer of plaster. The next morning, early, we all got up and began the process of plastering on the first layer of mortar. The mix for the mortar was 2 parts cement and 4 parts of the coarser sand. For more strength, the mortar needs to be only as wet as it has to be.

The team also invented a double ladder that went up and over the framework. This is because for every person plastering on the outside, someone has to be on the inside holding up an aluminum sheet with handles.

Lucien Joseph on the inside, holding up the aluminum sheet while Herve plasters. This is not a perfect process. A lot of times, the cement would fall instead of sticking to the framework. Ricot taught us to use our mistakes. The mortar falling around the edges, he explained, help in sealing the cistern's base.

Around and around, up and up. A look at what the plaster looks like from the inside.

After the cistern had its first layer, and the mortar had stiffened somewhat, Ricot showed us how to go around and fill in the holes. After the holes were filled in, we went and ate lunch.

Around 3:00 PM, we came back and kept going, adding two or three more layers of plaster all around on the outside, and one really thick layer of plaster on the inside.

Renaud, finishing up with the final layers on the outside.

Friday morning, April 24th, Ricot had us mix up a batch of mortar using the finest sand. This mix was to seal the cistern, and they did a layer on the inside and the outside. The mix was 1 1/4 parts cement and 2 parts fine sand. when this layer was starting to dry, they used the wooden floats to finish the sealing process. You can see Clermius with a piece of plastic bottle. He would throw a little water, then pass the float. Inside the cistern they did not use the wooden float; instead, they used a hard sponge.

Lucien and me, working on the gutters. The organization purchased 4" drainage pipe, which we cut on one side, then slid the pieces onto the tin roof. Herve and Lucien fixed the pipe using the #16 binding wire, wrapping it around the pipe and through any convenient spaces under the tin roofing. They are more confident on a home made wooden ladder than I am.

Local kids helping with the construction. Mario is on top of the double ladder, Anel is handing the mortar up. There are three or four masons inside to receive the mortar, which was for sealing the base of the cistern. On the roof you can see the PVC gutter, with the elbow just over the cistern. Herve, Lucien and I had to leave the final piece of the pipe for the folks from MRPST to put in, because the cistern was still too soft for us to lean a ladder from the inside.

Left to right: Samuel, Clermius, Renaud and Exode, sealing off the base with a thick coat of the mortar made with cement and fine sand (1 1/4 parts cement to 2 parts fine sand).

The almost finished cistern with the outlet for the water, ready to be connected to whatever type of faucet the organization wants. The top of the cistern has to wait until the cement has cured, at least 5 days, according to Ricot. The cistern also needs to be kept moist, sprayed with water at least twice a day. Or, Ricot explained, if it rains, you can start filling it with rainwater, as long as it has had 5 hours to harden. The team was finished by 10 AM Friday. Ricot and Exode were packed, bathed and dressed to head back to Papaye by 11 AM.
Valdir França (black shirt, far left) and Jo Ella Holman (beside him) listening to Mark Hare (blue shirt) translate for Ricot and the other masons. Valdir and Jo Ella arrived Thursday afternoon and listened to the masons as they explained what and why they were learning to build this type of cistern. Then later in the evening, they listened to the members of MRPST's executive committee tell the story about how MRPST came to be. Photo by Cindy Corell.
Mark Hare and Herve Delisma resting from working on the gutter, and frustrating Cindy Corell's efforts to get a decent picture. Photo by Cindy Corell (even if she won't admit it).

Wednesday, May 13, 2015

Biochar for Soil Mix

Buzz Durham (from Grace Covenant PC in Asheville, NC) in Léogâne, providing some ideas to workshop participants about using charcoal dust to create a biochar mix for vegetable tires. Buzz recommended starting with adding about 1 part charcoal powder to 6 parts "regular" soil mix. Our normal soil mix is 3 parts soil, 2 parts dried crushed manure (cow, horse and burro) and 1 part sand. So now we recommend 3:2:1:1, soil:manure:sand:charcoal powder. The exact proportion of soil and sand will depend on how heavy the soil is (how much clay it has) and also how fine the sand is. For example, I have a sand that is so fine, I just use it as soil, mixing it with the dried animal manure.  The next step is to fill the vegetable tires with the mix, wet them thoroughly, cover them with some type of mulch and leave them for a week to ten days. This give the charcoal time to convert into biochar--biologically active charcoal. Photo by Mark Hare
Biochar is charcoal used as a soil amendment. Like any charcoal, biochar is created by burning biomass of some type in the absence of oxygen (pyrolysis). Biochar is under investigation as an approach to carbon sequestration. (From Wikipedia: Wikepedia: Biochar).

As a soil amendment, we have started using charcoal powder in the soil mix we make for our vegetable tires. Because charcoal particles are extremely porous they can absorb water and nutrients. The tiny holes in each particle also create good places for beneficial microbes to live and develop.

All charcoal is not equal in terms of benefits, it turns out ("Gardening with Biochar" Gardening with Biochar). Some types of charcoal provide more nutrients ("bio-oil condensates") for the little beasties. More beasties (micro-organisms) means more life in the soil. Healthy soil means healthy plants. In addition to making nutrients in the soil more available to plants, a healthy soil micro-biology also provides plants a better defense from diseases caused by viruses and other pathogens.

In the mini-workshop that Buzz Durham led in Léogâne, September 2014, we used charcoal powder that had accumulated in the area within the local marketplace where charcoal merchants sell their product. The powder comes from the bits of charcoal that fall out of the sacks and then get crushed into powder by the weight of the sacks of charcoal sitting on it and by people constantly walking on it. The coordinator for farmer organization ODEPOL, Luxène Sommervil, collected two sacks of the powder there for free, and I brought one of them home to use in my family's vegetable tires here in Barahona (Dominican Republic).

If you don't have a local marketplace that sells charcoal, there are ways you can make charcoal in your backyard. Here is a demonstration of a simple way to do this, developed by Amy Smith from MIT: Amy Smith: Agricultural Charcoal. Commercial charcoal briquettes are not good because the material used to bind the charcoal may not be good for the soil.

One of the most important characteristics of the charcoal added as a soil amendment is that it is durable. We can add it once to our soil mixes and it will keep providing benefits for a very long time. The charcoal residues in the terra preta soils of the Amazonian rain forest are hundreds, possibly thousands of years old (Terra preta soils in the Amazon).

In terms of carbon sequestration, what this means is that by using a biochar system, we are capturing the carbon in the carbon dioxide (CO2) and storing it in ways that there is a net decrease in CO2 in the atmosphere.

Turning charcoal into biochar is something like learning to put the petroleum back in the ground, and then growing food with it.
Buzz detailing the benefits of using charcoal dust in soil mix. Photo by Mark Hare.

An experiment with biochar. The pot to the left has no biochar, the one in the middle has about 10% and the one to the right has about 20%. Photo from PowerPoint presentation by Larry Sthreshley, PC(USA) mission co-worker in the Democratic Republic of Congo. Used by permission.

A tire with tomatoes at our family's home in Barahona. The tire is filled with a mix of sandy soil, manure, compost and charcoal powder from Léogâne. Photo by Jenny Bent.

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