A project designed using local plants and finding just how well it survived the severe drought


Photo credit: New World Associates, Landscape Architects

Surviving the Drought

Posted by New World on Monday, April 3, 2017 Under: Drought
It’s great to visit a project designed using local plants and finding just how well it survived the severe drought we’ve been experiencing in Cape Town over the last few years!

Bloemhof Electricity Headquarters was constructed in winter 2013 and had established over 3 summer seasons before the water was turned off in November 2016 with the onset of Stage 3B water rationing, no irrigation! This is the ultimate test of a planting scheme’s success.

We visited site in late March 2017 after 5 months of a very hot, dry and windy summer wondering what we would find. Thankfully, it was a success! Over 90% of the planting survived, probably over 95% in ground, but only about 50% of roof planters survived sadly. That was the end of over 3 years of good growth and full development of the shrubs.

The secret to the success can be put down to good soil preparations, careful plant choice, and the advantage of 3 years establishment albeit that the last two summers were in drought. Irrigation was always limited on the project to hand watering on an as-needed basis, so the plants were slowly weaned off wet nursery conditions.

It was interesting to see that the soil conditions were patchy and a couple dry places with higher plant losses or droughting occurred. It remains to be seen if these plants will recover from dropping their leaves, a typical drought response, or if the plants have succumbed. Wild Rosemary seemed to suffer the most in one area drier than elsewhere.

On the other hand, there were beds in the car parks naturally watered from permeable paving; the restios planted there, which are typically quite drought sensitive and died elsewhere, were thriving, lush and green, from all the water that penetrated the paving and was directed under their roots.

Lessons learnt: good soil preparations, and we used a soil wetter called Terracottem to boost soil water retention, composting, mulching, and good plant research and selection, came together to produce a scheme that has substantially survived the drought, saving on replanting costs and reducing precious potable water consumption.

Read: http://new-world-associates.com/blog/surviving-the-drought

TerraCottem for erosion control of sandy soils all over the world


Photo credit: WVC

Erosion control of sandy soil by appying TerraCottem soil conditioner in the Antwerp harbour area

by Prof. Dr. Willem Van Cotthem (Ghent University, Belgium)


With the purpose of creating a new dock in the vicinity of Antwerp (Belgium), a large area was covered with sandy bottom sediments of the river Schelde, excavated by dredging. As these newly formed sandy soils are mostly nutrient deficient, it is extremely difficult to cover them with a vegetation layer to control wind erosion.  Their fertility and water retention capacity is generally too low, so that seeding with traditional grass species is mostly inefficient.  Even if these grasses germinate after some good rains, the young plants perish because the sand is unable to retain sufficient moisture and nutrients.

As a result of this drought and nutrient poverty, the young grasses will soon dry, which automatically leads to erosion, particularly in between the seeding lines of the grasses (see picture above).

In order to sustain an efficient vegetation layer on newly formed sandy soils, one has to condition those soils to improve their water retention capacity and fertility.  Thats’s where the soil conditioning technology TerraCottem (www.terracotten.com) plays an important role.

The TerraCottem soil conditioners are a proprietary mixture of more than twenty components each from different groups all assisting in the plant growth processes in a synergetic way (see: http://www.terracottem.com/terracottem-soil-conditioning-technology):

  • The growth precursors play a very important role in the initial growth phase of the plant. They activate root cell elongation and differentiation, and promote leaf development and biomass production.  In addition, roots are encouraged to grow more rapidly to depths where more water is present.
  • The cross-linked hydroabsorbent polymers absorb and store water that is normally lost to evaporation and leaching, reducing the volume and frequency of necessary irrigation by up to 50%.  This water is then kept at the disposal of the plant that accesses the stored water on demand through its root hairs, keeping the water in the root zone for a longer period of time.
  • The specially selected fertilizers provide balanced nutrition to the plants based upon macro and microelements.
  • TerraCottem’s carrier materials are selected for their chemo-physical properties (CEC, WRC, etc.) and their characteristics which allow homogeneous distribution of all components.

In view of an optimal development of a grass layer (turf), TerraCottem Turf has been developed. “Based on the TerraCottem principle, it contains zeolite, a 100 percent natural volcanic mineral that helps increase soil fertility and water retention.  The product’s benefits are further boosted by the inclusion of turf specific fertilizers and humic acids which have a positive effect on water retention capacity, soil structure and microbiological activity.   All this, to get quicker grass establishment, enhanced root and plant growth and improve the quality of turf, seeded grass and sprigs.”

At the start of our experiment in the Antwerp harbour area, the yellow sandy surface was completely barren and wind erosion was dramatic.  The experimental perimeter was divided into two parts:

(1) Left side of the photo above: The untreated part where a mixture of traditional grasses was directly sown in the sandy soil.

(2) Right on the photo: The TerraCottem-treated part (100 g per square meter, to a depth of 30 cm).

Thanks to some good rains, the grasses of the untreated part germinated and developed into a vegetation layer in which the seeding lines remained visible weeks after the start of the experiment.  During windy periods, sand grains were blown out from these uncovered parts between the grass lines.  Wind erosion and drought effect continued and finally the grasses died (see brown grasses in the picture).

Due to the improved water retention capacity and the higher fertility at the TerraCottem-treated part, the grasses developed soon into a closed turf layer, where wind erosion was totally reduced (see green “pasture” at the right hand side of the picture).

This experiment showed clearly that the soil conditioner TerraCottem is an excellent tool in the combat of erosion.  It deserves to be applied at the largest scale in the combat of desertification and all the applications to mitigate drought.




Disposable diaper farming (Willem Van Cotthem)

Read at :


“Drastic Measures

How about taking Willem Van Cotthem’s idea (“Diaper Farmer”) a step further and scattering a million or so used baby diapers over a desert? The hydrogel would absorb dew that settles overnight, and the diaper contents would provide nutrients.  The remainder of the diaper should disintegrate rapidly in the hot sun, and our dumps would be relieved of tons of waste.

Jack Bass

West Hartford, Conn.”


My sincere thanks go to Jack Bass for commenting on Bruce GRIERSON’s article, published in Popular Science, under the title “Diaper Farmer” – Willem van Cotthem’s super-soil harnesses the power of Pampers to turn dirt into lush gardens“.

2010-07 – Article published in Popular Science

I fully understand Jack Bass’ hypothesis that it might be possible to use diapers as such, but I am afraid that things are not that simple.

In order to react constructively upon Jack Bass’ hypothesis that we could make a desert area fertile by scattering used baby diapers over its surface, I want first to highlight the following elements of Grierson’s text :

  1. But water alone won’t make gardens flourish in sand.
  2. So van Cotthem invented a ‘soil conditioner’ called TerraCottem.  It’s an 8- to 12-inch layer of dirt impregnated with hydrogels, along with organic agents that nourish the natural bacteria in the soil.
  3. Until only recently, though, hydrogels were toxic, and skeptics doubted that they could ever be made safe for consumption.

1. The importance of water

According to our actual knowledge, plant life is totally impossible without water, every living plant cell containing a high percentage of it.  Seeds can only germinate if sufficient water is present to start up the cell divisions within the embryo in the seed.  Newly formed cells in the root(s), the stem and the leaflets need water to expand to their adult volume.  A growing seedling, before breaking out of the seed, is therefore full of water. Once the primary root leaves the seed coat to enter in contact with the soil, it needs to find some moisture in the small cavities of that soil or at the surface of the moistened soil particles.  If that minimal quantity of water is not available, the primary root will not continue its growth and die off rather quickly. So, water is absolutely necessary to get plants growing, particularly in sand.

But water alone won’t make gardens flourish in sand.

Seedlings, and later on young plants and even adult plants, need to absorb through their roots not only water, but a solution of mineral elements (nutrients) in water.  Therefore, if one wants to “make gardens flourish in sand“, a number of nutrients have to be dissolved in the soil moisture to enable their uptake by the roots and their incorporation in some synthesis processes of the biomass, the plant body.

For this reason, it is interesting to know that the different hydro-absorbent hydrogels, that we have chosen to be components of the TerraCottem soil conditioner, not only absorb water but also the solution of nutrients in water.  Inside the hydrogels, swollen into gel lumps when absorbing that solution, one will not only find a considerable amount of water, but also different major nutritive elements for the plants, e.g. Ca, Fe, N, P, K, S, …

This indicates clearly that the soil conditioner TerraCottem offers all the major elements for the plant’s growth, a lot of water and the major nutrients, to the absorbing roots.

Therefore, TerraCottem makes the gardens flourish in sand, water alone doesn’t.

2. The effect of TerraCottem on soil and plant

Grierson called TerraCottem: an 8- to 12-inch layer of dirt impregnated with hydrogels, along with organic agents that nourish the natural bacteria in the soil.

I want to precise that TerraCottem is NOT a layer of dirt impregnated with hydrogels, but a granular soil conditioner, a compound of more than 20 different substances (hydroaborbent polymers or hydrogels, mineral fertilizers, organic substances, rootgrowth activators and volcanic rock – for its exact composition see www.terracottem.com).

This compound of mineral and organic substances has to be mixed with an  8- to 12-inch layer of dirt in order to condition that “dirt” (the local soil), i.e. to give it a higher water retention capacity (with its hydrogels), a higher fertility (with its mineral NPK-fertilizers), a higher organic content (with its organic substances), a higher root activating property (with its organic root activators) and a higher air retention capacity (with its volcanic rock granules).

Mixing  a certain dosage of TerraCottem soil conditioner with a given volume of dirt or soil creates all the different improvements mentioned above, resulting not only in the nourishment of the natural bacteria and other organisms in the soil, but principally in a better plant growth, in particular a maximal biomass production with a minimal of water.  Yes, TerraCottem stimulates also the development of benign natural bacteria in the soil, and this in turn will activate the mineralisation process, setting free  a lot of beneficial elements.

3. Toxicity and usefulness of hydrogels

A general description of hydrogel properties can be found at gz.e:


To understand clearly the nature, composition and significance of hydrogel applications, one can find a lot of information on Wikipedia (search “Hydrogels”).

A clear view on the history of super-absorbent polymers is given in http://en.wikipedia.org/wiki/Superabsorbent_polymer

“Until the 1980’s, water absorbing materials were cellulosic or fiber-based products. Choices were tissue paper, cotton, sponge, and fluff pulp. The water retention capacity of these types of materials is only 20 times their weight – at most.

In the early 1960s, the United States Department of Agriculture (USDA) was conducting work on materials to improve water conservation in soils. They developed a resin based on the grafting of acrylonitrile polymer onto the backbone of starch molecules (i.e. starch-grafting). The hydrolyzed product of the hydrolysis of this starch-acrylonitrile co-polymer gave water absorption greater than 400 times its weight. Also, the gel did not release liquid water the way that fiber-based absorbents do.

The polymer came to be known as “Super Slurper”. The USDA gave the technical know how to several USA companies for further development of the basic technology. A wide range of grating combinations were attempted including work with acrylic acid, acrylamide and polyvinyl alcohol (PVA).”

Polyacrylate/polyacrylamide copolymers were originally designed for use in conditions with high electrolyte/mineral content and a need for long term stability including numerous wet/dry cycles. Uses include agricultural and horticultural. With the added strength of the acrylamide monomer, used as medical spill control, wire & cable waterblocking”

From the Wikipedia-data above can be deduced that not all the highly water absorbent hydrogels are safe to be used in nature.

One of the parameters of our screening tests when developing the soil conditioner TerraCottem was precisely this possible toxicity of the hydrogels.  At the end of the day we had to be sure that none of the TerraCottem hydrogels were toxic.

The TerraCottem website (www.terracottem.com) offers a lot of interesting information on the hydrogels, particularly in the section of

Frequently asked questions about the TerraCottem soil conditioning technology” :

Once for 100% sure about the non-toxicity of the water absorbing hydrogels, we were able to add to them substances belonging to different chemical groups without any danger of creating problems with soil treatment.

Hossein OMIDIAN and Kinam PARK in the

“Biomedical Applications of Hydrogels Handbook”

express their concern about application of hydrogels in diapers as follows:

Although the absorbent hydrogels  can keep the skin area dry, there is a serious concern that these synthetic materials can increase the incidence of diaper dermatitis.  Their non-biodegradability, toxicity, and environmental pollution are also of concern.”

Recently, descriptions of some alternatives for these “toxic” diapers have been published, e.g. the gDiapers, and the diapers from Seventh Generation.

The gDiapers description mentions  two parts:  a washable cloth part and a disposable, flushable liner, breaking down in the toilet. The Seventh Generation disposable diapers are said to be chemical free.

Here is the Handbook’s interesting summary:

“Crosslinked hydrophylic polymers provide superior physical, chemical, and environmental properties in their wet state.  These features have made hydrogels invaluable in numerous disciplines including: hygiene, agriculture, biomedical, and pharmaceutical.  Successful design of a hydrogel for a specific application requires careful understanding of the application and the environment that the hydrogel is intended to serve.  Although challenging, a hydrogel can be tailored to address some special need in almost any discipline due to the wide spectrum of synthetic and natural hydrogel structures and processing technologies available.”

Several times, the hope has been expressed that the producers of disposable diapers would be willing to change the production process of their diapers to make them more environmentally friendly. However, websites of many disposable diaper manufacturers show only poor information on MSDS (Material Safety Data Sheets).

4. Properties of disposable diapers

Let me first list a number of interesting quotes from Wikipedia’s diaper description:

  • The decision to use cloth or disposable diapers is a controversial one, owing to issues ranging from convenience, health, cost, and their effect on the environment.
  • In the 20th century, the disposable diaper gradually evolved through the inventions of several different people.
  • Disposable diapers were introduced to the US in 1949 by Johnson & Johnson.
  • In 1956, Procter & Gamble began researching disposable diapers. Victor Mills, along with his project group including William Dehaas, both men who worked for the company, invented what would be trademarked “Pampers”.
  • Over the next few decades, the disposable diaper industry boomed and the competition between Procter & Gamble’s Pampers and Kimberly Clark‘s Huggies resulted in lower prices and drastic changes to diaper design. Several improvements were made, such as the introduction of refastenable tapes, the “hourglass shape” so as to reduce bulk at the crotch area, and the 1984 introduction of super-absorbent material from polymers known as sodium polyacrylate that were originally developed in 1966.

Nowadays, and all over the world, every child wares diapers from its birth until it is potty trained (some 8000 diapers in 2 to 4 years).  Due to their chemical composition, disposable diapers do not biodegrade easily, so that landfills contain a high percentage of these diapers.

Scientists studied the complete life cycle of different types of diapers (cloth ones and disposable ones): materials used, chemicals included, and energy consumed during production, usage and disposal. Their possible environmental impact on toxicity, acidification and eutrophication was analysed.  A number of these studies showed that most of today’s diapers contain some toxic chemicals, which makes them useless to improve the soil qualities.

For a better understanding of this problem, one can read the Wikipedia-description of diapers:


An interesting study on the “USE OF DIAPER POLYMERS AS SOIL CONDITIONER” was published by a Portugese team:

Shahidian S., Serralheiro R.P., Serrano J., Machado R., Toureiro C. and Rebocho J.
(see www.ramiran.net/ramiran2010/docs/Ramiran2010_0309_final.pdf)

In their introduction, the authors describe the properties and use of super absorbent polymers (SAP). They confirm that “Over the past years there has been a continuous reduction in their price and a generalized use of disposable diapers in the developed and some parts of the developing world. Although there are no global statistics, each child uses approximately 30 kg of polymers in his first two years of life, filling the landfills with around 400 kg of waste. However, diapers are not necessarily un-reusable waste, and SAPs have been successfully used as soil amendments to improve the physical properties of soil in view of increasing their water-holding capacity and/or nutrient retention, especially in sandy soils. SAP hydrogels potentially influence soil permeability, density, evaporation, and infiltration rates of water through the soils. Potentially, the hydrogels can reduce irrigation frequency and compaction tendency, stop erosion and water run off, and increase the soil aeration and microbial activity.

The objective of their study was “to evaluate the viability of recycling used diaper filling in agriculture, as a soil amendment. To achieve this goal, the effect of diaper filling on soil available water, crop water stress and production had to be studied, since diapers contain varying amounts of bleached cellulose fiber and other additives besides SAPs, which influence the overall effect of diaper addition to the soil.”

The study indicates that a diaper may contain as much as 10 g of SAP and that the polymer must be able to absorb liquids even when it is being pressed.

Concerning the use of polymers in agriculture, it was said that “over the past three decades both soluble and insoluble polymers have been used. Watersoluble polymers, such as polyacrylamides (PAM) have been used extensively to stabilize the soil structure and to increase infiltration and reduce runoff and erosion. Insoluble water-absorbing polymers can be divided into three main groups: the starch-graft co-polymers, the polyacrylate type widely used in disposable diapers, and the acrylamide-acrylate co-polymers, used in agriculture because of their great capacity to expand and absorb water under pressure, thus not only providing plants with water, but also helping to aerate the soil.”

The following beneficial effects of the hydrogels were listed:

  • reduce irrigation frequency;
  • reduce compaction tendency;
  • stop erosion and water run off;
  • increase the soil aeration;
  • increase the microbial activity.

A study of the effect of an amendment of sandy soil with highly cross-linked polyacrylamide on Aleppo pine seedlings during water stress  showed that the survival rates in 0.4% hydrogel were doubled,  allowing the seedlings to tolerate drought for 19 days.

Another study showed that water retention capacity of a sandy soil was significantly increased by 23 and 95% with addition of 0.03 and 0.07% polymer, respectively, and water use efficiency increased by 12 and 19% with the application of 0.03 and 0.07% w/w polymer, respectively.

Addition of an hydrogel to saline soil improved seedling growth of a salt tolerant poplar species during a period of 2 years. Root length and surface area of treated poplars was 3.5 fold more than those grown in untreated soil. Hydrogel treatment enhanced the Ca2+ uptake and increased the capacity of that salt-tolerant poplar to exclude salt (i.e. reduces contact with Na+ and Cl-).  This is another interesting aspect of hydrogel amendment, improving plant growth on somewhat saline soils.

The SAPs used in agriculture are polyelectrolyte co-polymers, often composed of acrylamide and potassium acrylate. This makes them swell much less in the presence of monovalent salts and collapse in the presence of multivalent ions, present in the soil or in fertilizers.

Most SAPs are moderately bio-degradable in the soil, converting finally to water, carbon dioxide and organic matter, leaving no undesirable chemicals in the soil or in the environment. No adverse effect has been shown on microbial populations and their toxicity for mammals is almost nonexistent.

In its experiments, the Portugese team used only new diapers in order to isolate the influence of the diaper SAP and fiber from that of the urea and other organic compound present in used diapers. The treatment plots received 100g per square meter of dry diaper content (the equivalent of 10 diapers), which was mixed in the 0.2 m topsoil prior to planting. This is roughly equivalent to 0.2 g per kg of soil. Thus, diaper filling (cellulose and SAPs) were added to soil at the lower limits recommended by literature. Where other researchers found that SAPs enhance available water in the soil, the Portugese team reported that the adding of diaper filling had a negative effect on both available soil water and crop production. Thus, their data are not in line with the general findings: SAPs increase crop survival and biomass production. It was therefore decided to carry out further experiments, especially with different concentrations of diaper fillings and different crops in order to encounter the right balance for using diaper fillings as a soil ameliorant.

5. Components of a typical disposable diaper

The basic components of a typical disposable diaper are already described in detail by Richer Investment Diaper Consulting Services (2007):


  1. A back sheet, preventing liquids from leaking out of the diaper, made of plastics (polyethylene) or breathable cloth-like material.
  2. A special tissue paper with high elasticity and wet strength, used as a carrier for the pad.
  3. Hot melts (resins, oils, tackifiers) to glue the different components of the diapers (pad and elastics).
  4. Hydrophobic Non-woven: top sheet for the leg cuffs to prevent leakage, made of polypropylene resin.
  5. Hydrophylic Non-woven: top surface that is in contact with the skin, with surface surfactants allowing the liquids to flow into the diaper core.
  6. Elastics in cuffs for waist and legs, made of polyurethane of polyester foam.
  7. Lateral tapes for mechanical grip, made of velcro or polypropylene adhesive tabs.
  8. Frontal tapes to facilitate multiple repositioning of the lateral tape, made of polypropylene film.
  9. Cellulose pulp from pine trees in the pad for absorbing liquids in the void capillaries between the fibers.
  10. Acquisition and distribution layer between the top sheet and the absorbent core to provide a sense of dryness by additional separation between the pad and the skin, made of non-wovens or fibers.
  11. Sodium polyacrylate (super-absorbent polymer or SAP): fine granules to improve liquid retention and keep the pad thinner (less pulp).  In contact with water, the sodium detaches itself and the polymer absorbs water, solidifying into a gel.
  12. Top Sheet surface add-on lotions, like Aloe vera, vitamin D or E, almond oil, oat extract, jojoba, etc.
  13. Decorated films (different inks) and wetness indicators.


6. Disposable diapers and the environment in the past

The American Real Diaper Association described a number of diaper facts (health, environment, dryness and rash, cost):


Here are some facts about the environment:

  • Based on their calculations, they estimated that 27.4 billion disposable diapers are consumed every year in the U.S. and 92% of all single-use diapers end up in a landfill.
  • In 1988, nearly $300 million dollars were spent annually just to discard disposable diapers, whereas cotton diapers are reused 50 to 200 times before being turned into rags. No one knows how long it takes for a disposable diaper to decompose, but it is estimated to be about 250-500 years.
  • Disposable diapers are the third largest single consumer item in landfills, and represent about 4% of solid waste.
  • Disposable diapers generate sixty times more solid waste and use twenty times more raw materials, like crude oil and wood pulp.
  • The manufacture and use of disposable diapers amounts to 2.3 times more water wasted than cloth.
  • Over 300 pounds of wood, 50 pounds of petroleum feedstocks and 20 pounds of chlorine are used to produce disposable diapers for one baby EACH YEAR.
  • In 1991, an attempt towards recycling disposable diapers was made in the city of Seattle, involving 800 families, 30 day care centers, a hospital and a Seattle-based recycler for a period of one year. The conclusion made by Procter & Gamble was that recycling disposable diapers was not an economically feasible task on any scale.

7. Disposable diapers and the environment in the future

It goes without saying that the discarding of disposable diapers is one of the major problems for the environment (see figures above).

Taking into account :

  • That the global landfills contain billions of tons of used disposable diapers (4 % of all solid waste);
  • That the disposable diapers are still made of synthetic materials that biodegrade extremely slowly in landfills;
  • That the presence of some toxic synthetic materials in today’s diapers may create a number of health problems;
  • That the presence of water absorbing sodium acrylate






25,000 die each day

Photo credit:

Community garden in Niou (Prov. Kourweogo, Burkina Faso) in 2009 – Project Committee Maastricht-Niou and TC-Dialogue Foundation (Belgium) started in 1988. – Soil conditioned with TC – Photo Willemien 2009 Niou Jardin Communautaire P2250398 copy 2.


Although success stories to alleviate hunger exist, 25,000 die each day – (bewing)

Commented by Prof. Dr. Willem Van Cotthem (Ghent University, Belgium)

published at: https://desertification.wordpress.com/2007/03/31/469/

In Bewing http://bewing.wordpress.com/2007/03/28/25000-die-each-day/#comment-693:


“About 25,000 people die every day of hunger or hunger-related causes, according to the United Nations. This is one person every three and a half seconds, as you can see on this display. Unfortunately, it is children who die most often.Yet there is plenty of food in the world for everyone. The problem is that hungry people are trapped in severe poverty. They lack the money to buy enough food to nourish themselves. Being constantly malnourished, they become weaker and often sick. This makes them increasingly less able to work, which then makes them even poorer and hungrier. This downward spiral often continues until death for them and their families.”

Senegal Toubacouta 2002-02
Senegal Toubacouta 2002-02

2002-02 : Toubacouta (Senegal) – Community garden for women in the Sahel region – Excellent production with only half of the normal quantity of irrigation water – Look at the dark, healthy, continuously moistened soil. –

Project TC-Dialogue with Philippe BEKAERT and Alain GOETGHEBUER (sponsors, Belgium) – Keur Bou Natte – Photo WVC 2002.

2003-03 Espargos-Pretoria-06 copy
2003-03 Espargos-Pretoria-06 copy.jpg

Project of TC-Dialogue Foundation – Evaluation mission 2003-03 with Etienne Van Steenberghe and Marc PIlle : Cabo Verde (Isla do Sal – Escola Pretoria) – Splendid school garden – Former schoolyard transformed into a “garden of Eden”, producing fresh vegetables for the lunches at school, thanks to the application of the TerraCottem (TC) soil conditioner. See the happy children ?  

Photo WVC 2003-03 Espargos-Pretoria-06 copy.jpg


P1000569 copy 1
P1000569 copy 1.jpg

UNICEF Project with TC-Dialogue Foundation 2005-2007: Saharawis refugee camp of Smara (S.W. Algeria) – Sahara desert sand transformed into a magnificent family garden (25 m2, sufficient to feed the family). Soil conditioner TerraCottem applied in october 2006; first vegetables (red beetroot and carrots) harvested in november 2006. For the first time all the family members can eat fresh vegetables from their own garden. –

Photo WVC P1000569 2007 Smara TV4.JPG.


Hunger and famine belong to the most shocking and disastrous phenomena on this world. We all get really touched when seeing hungry children, mostly in the drylands, where poverty of the rural people is one of the basic reasons for this plague.

Therefore, it is striking that very positive results, obtained since the nineties with creation of community gardens for women (Burkina Faso, Senegal), school gardens (Cabo Verde, Burkina Faso) or small family gardens (Algeria), do not seem to convince international or national authorities to invest seriously in these easy to duplicate “best practices” to alleviate hunger and poverty.

If local farmers, mostly women, can produce more crops with half of the normal volume of irrigation water, simply by applying one single time a soil conditioner, why don’t we invest more in the multiplication of vegetable gardens for villagers and school children?

Have a look at my blog <www.desertification.wordpress.com>, see what we have done with UNICEF ALGERIA for the creation of family gardens in the refugee camps of the Sahraouis people in the Sahara desert, and you will be convinced that a nice solution for the hunger problem exists.

It suffices to apply it to break the downward spiral. I know that the rural population in the drylands lacks the money to buy enough food and being constantly malnourished, is becoming weaker and often sick. Fabulous amounts of money have been and are continuously spent on very diverse, ambitious, but sometimes non-sustainable programmes and projects. What if we would invest in the creation of kitchen gardens and school gardens, offering the rural people and their children a nice opportunity to produce their own food, even within a period of 2-3 months? Production of fresh food, full of vitamins and mineral elements, makes them increasingly more able to work, which then makes them even less hungry and a bit wealthier (possibility to bring vegetables to the local market).

I see no easier and better way to create an upward spiral. And remember, seeing is believing. That’s what the Saharawis have been telling us after registering the first successes with their new gardens and trees in the Algerian Sahara desert.  Why only here, in the most difficult circumstances ?  Why not in all the drylands ?

The day will come …


Plantation d’une haie vive au Burkina Faso


Photo credit : Henri GIRARD – AZN – Living hedge planted in 1998 with 100 g of TC soil conditioner per linear meter – Two rows of Cassia sieberiana

Plantation of a living hedge in Burkina Faso

in Guié/ Tankouti

Testing a soil conditioner by Henri GIRARD, AZN – Terre Verte Burkina

“Burkina Faso – woody savannah of Guié/Tankouri (Oubritenga Province) : mixed living hedge (composed of a sheep fence installed between two rows of Cassia sieberiana), planted with TerraCottem (TC) soil conditioner in 1998 (100 g of TC per linear meter, at the bottom of a ditch, 40 cm wide and 30 cm deep).  First pruning at 120 cm in March 2005.  Height of the hedge in 2006 : 280 cm (excellent growth without any irrigation).  Observations : regular survival of all seedlings in comparison with those on other sites in the region (Photos Henri GIRARD, AZN – Terre Verte Burkina-2006/01).”

2006-01-Haie-Tankouri-TC-40.jpg – 

Photo credit: Henri GIRARD – 2006-01: Living hedge planted in 1998 with 100 g of TC soil conditioner per linear meter – Two rows of Cassia sieberiana

“Burkina Faso – périmètre bocager de  Guiè/Tankouri (province d’Oubritenga) : haie vive haie  mixte (composée d’un grillage mouton enserré entre 2 lignes de Cassia  sieberiana), plantée  avec le TC en 1998 (100  grammes de TC par mètre linéaire, au fond d’une tranchée de 40 cm de large et 30 cm  de profondeur). Première taille à 120 cm en mars 2005. Hauteur de la haie  en 2006 : 280 cm (excellente croissance sans irrigation aucune). Observations: Régularité de reprise des pieds par rapport à  ceux d’autres sites dans la région  (Photos Henri GIRARD, AZN – Terre Verte Burkina–2006/01).”

Use of TerraCottem soil conditioner (TC) in Chinese greenhouses

Photo credit: WVC 1999-11

Use of TC in a Chinese greenhouse in HongHe (Gansu Province (P.R. China)


Report of the Chinese partner of a Belgian project set up by the TC-Dialogue Foundation

(1) English translation

(2) Chinese text

presented by Prof. Dr. Willem Van Cotthem (Ghent University – Belgium – Chairman of TC-Dialogue Foundation)







Photo WVC: Chinese greenhouse with garlic growing on soil treated with TC.
Photo WVC: Chinese greenhouse with garlic growing on soil treated with TC.
Photo WVC: Commemoration plate of the TC project in Hong He (Gansu Province, P.R. China).
Photo WVC: Commemoration plate of the TC project in Hong He (Gansu Province, P.R. China).
Photo WVC: Backside of the commemoration plate.
Photo WVC: Backside of the commemoration plate.





Community garden for women

Photo credit WVC 2000-07-02-Sorghum.jpg

During the rainy season the landowner occupies the field to plant Sorghum.  As the soil in the community garden (background) has been conditioned with TerraCottem in 1997 and the village women have since that year laboured the garden, sorghum production is significantly higher in the garden than in the surrounding fields.  See the 2-3 meter high sorghum in the background and the 50 cm high one in the foreground.


Community garden (Horticulture) in Burkina Faso

by Willem Van Cotthem (Ghent University – Belgium)

Together with my team of the Ghent University and in cooperation with the Dutch Committee Maastricht-Niou, I have set up different development projects in Burkina Faso since 1988. Reforestation and creation of community gardens for women have been the main topics (see other postings).

In 1997, we started the application of the soil conditioner TerraCottem (TC), as a project of the Belgian TC-DIALOGUE Foundation. In the community garden for women of the village of Niou (Kourweogo Province, Burkina Faso), some 2500 square meter of the vegetable garden were treated with that water and fertilizer saving soil conditioner. A smaller part of the garden remained untreated (control plot).

Capacity building
Photo WVC 1997-07: Capacity building in the garden : members of the local women’s association Gueswende got information about TC-application and its role (Photo Monique Van Endert 1997)

First labour phase : preparing the garden beds (1 m broad to make cultivation actions from both sides more easy). The hard, sun dried soil is broken to a depth of 20 cm, a very difficult job because of the small and simple tools.

Preparing garden 01
Photo WVC 1997-07: Breaking the hard and dry soil was a very painfull job for every woman

Second phase : spreading the granular TC over the surface at the right rate (100 g TC per square meter equals 3 handfulls).

Photo 1997-07: Gueswende’s president showed the female members and some young men of the village how to distribute TC over the cultivation beds (Photo Monique Van Endert 1997)

As the application is really easy, all local women soon started to cover their garden beds with the white TC-granules.

Distribution TC 02
Photo WVC 1997-07: Every garden bed was treated with the optimal dosage of TC

Third phase : once the garden beds covered with TC, the women started mixing it with the soil by turning it over to a depth of 20 cm with their handmade digging hoes. They sustained their labour rhythm with a traditional song.

1997-07-Preparing garden 03
Photo WVC 1997-07-Preparing garden 03: Women singing while doing the hard work

In December 1997, we visited this community garden of Niou again, accompanied by Luc VAN LOON, journalist of the Belgian FLAIR magazine, who wrote different articles on development cooperation in Burkina Faso. Nice pictures were taken by photographer Monique VAN ENDERT. The desertified poor garden was totally transformed into a lush green oasis, surrounded by some trees, e.g. Eucalyptus trees, acidifying the soil underneath.

1997-12-01-General view 01 copy
Photo M. VAN ENDERT 1997-12-01-General view 01 copy – Five months after the start of the project, the community garden is like an oasis in the extremely dry area

Fourth phase : in this garden, each of 36 local women cultivated many beds with a number of vegetable species : tomato, cabbage, lettuce, onion, egg plant, raddish, red beet, potato etc. Some irrigation water was at hand in two garden wells and distributed with buckets. Thanks to the presence of the water stocking TC in the soil, only 50 % of the normal irrigation volume was needed to keep the garden beds in good condition, sufficiently humid to avoid hydric stress for the vegetables. Less irrigation needed, also means less labour and more time free for the family or other duties. Plant growth was remarkably good. With half of the irrigation water, production went up to the double.

1997-12-02-General view 02 copy
Photo M. VAN ENDERT 1997-12-02-General view 02 copy: The TC-treated garden was very productive and well kept (almost no weeds)

Each woman decided for herself what kind of vegetables to cultivate. Some produced tomatoes and potatoes, others onions and radishes, cabbages and egg plants or juicy lettuce. What a pleasant feeling to see the splendour of this garden and to listen to the happy women, chatting around the wells.

General view 04Photo M. VAN ENDERT 1997-12-04-General view 04: Garden beds in excellent condition, continuously moistened with the TC up to 20 cm deep

A community garden, where a large number of local women can work together, is also a daily meeting place to improve social contacts. Central point of such a garden is the well. Babies accompany their mother to the garden and stay in the shadow of the trees, where also mint tea is cooked.

General view 07Photo WVC 1997-12-07: Watering the vegetables only takes half of the normal time (50 % irrigation is sufficient to keep the soil humid).

The importance of TC-application in horticulture was easily shown when comparing the vegetable production with that in the non-treated part of the garden. Significant differences in plant production were registered.

1997-12-Non-treated part
Photo WVC1997-12-Non-treated part of the community garden: Less production of vegetables, significantly poorer than the TC-treated part.


Moreover, the women had to irrigate these untreated beds twice a day to keep the soil moistened. Only half of the production with a double volume of irrigation water ! Again a success story in the combat of desertification and the alleviation of poverty. Indeed, the women took a certain part of the vegetables to the local market, thus enhancing their annual income.

Originally published at:


Soil conditioner against urban desertification

Photo credit: Photo WVC 1999-06:

Australia Sydney Cockle Bay Wharf 2

Success project for TerraCottem (TC) in Australia

by Willem Van Cotthem (Ghent University – Belgium)

When preparing for the Olympic Games in 2000, the authorities of the City of Sydney decided to create a dramatic change in certain parts of the city by introducing spectacular plantations of trees, shrubs and flowering plants. To name only two wellknown areas in the city center that turned completely green in a very short period : Cockle Bay Wharf and Darling Harbour. The secret for this fantastic success : the use of TerraCottem soil conditioner (TC) in the containers at the waterside of Cockle Bay Wharf and on the roof top of Darling Harbour, where a huge hanging garden was created (www.terracottem.com).

1999-06: Photo WVC: Cockle Bay Wharf became green in some weeks before the Olympic games
1999-06: Photo WVC: Cockle Bay Wharf became green in some weeks before the Olympic games
Photo WVC 1999-06: Cockle Bay Wharf ready for the Olympic games
Photo WVC 1999-06: Cockle Bay Wharf ready for the Olympic games

TerraCottem soil conditioner was applied to solve the problems of regular watering of the containers with trees, shrubs and ornamental plants, used to embellish the waterfront at Cockle Bay. The potting soil in the containers was mixed with TC at a dosage of 5 g TC per kg of substrate. As TC stocks water and nutrients, it limits the need for regular irrigation in a significant way. As it also stimulates root growth and microbiological activities in the substrate, it improves plant growth in a spectacular way, whilst reducing water and fertilizer consumption.

Photo WVC 1999-06: Sydney Darling Harbour rooftop garden
Photo WVC 1999-06: Sydney Darling Harbour rooftop garden

For the same need of limiting the volume of irrigation water and fertilizers, the City of Sydney decided to mix TC soil conditioner with the substrate on the rooftop (also less weight !). A number of weeks after planting and seeding with typical species of the 5 continents, this rooftop garden became a splendid success. It is visited every year by tenthousands of visitors.

A birdseye view on Darling Harbour rooftop garden
A birdseye view on Darling Harbour rooftop garden

These two success stories with TerraCottem soil conditioner in landscaping projects of a city like Sydney show that TC can be used in extreme conditions for saving water and fertilizer. What was realized within the “concrete desert” of this city, can also be achieved in other cities of the world and in all desertlike areas of the drylands.

Photo WVC 1999-06: Sydney Darling Harbour rooftop garden
Photo WVC 1999-06: Sydney Darling Harbour rooftop garden

Greening of a rooftop or an avenue is submitted to the same irrigation problems as a reforestation project or a vegetable garden in the drylands. TC can be used as an effective tool in the combat of desertification.

Originally published at:



How one can combat hunger and malnutrition in the desert

Photo credit: Martin Dewhurst

Engineer Taleb Brahim in one of the food producing gardens in the Sahrawi camps (Algeria)

Family gardens in refugee camps in the Sahara desert (S.W. Algeria)

Messages and photos published by Martin DEWHURST (UK) on Facebook

Small scale food production in the Sahrawi refugee camps, south west Algeria. In the July the average daytime temperature is 45°C.  - Photo Philip Hittepole - https://scontent-fra3-1.xx.fbcdn.net/hphotos-xpt1/v/t1.0-9/12112271_10153723290555844_4717751630392217978_n.jpg?oh=f47b818591fef4afc2d5528b2f87d4d2&oe=5695D8DE
Small scale food production in the Sahrawi refugee camps, south west Algeria. In  July the average daytime temperature is 45°C. – Photo Philip Hittepole – https://scontent-fra3-1.xx.fbcdn.net/hphotos-xpt1/v/t1.0-9/12112271_10153723290555844_4717751630392217978_n.jpg?oh=f47b818591fef4afc2d5528b2f87d4d2&oe=5695D8DE

There are a number of remarkable things about these gardens … where they are in the Sahara desert, the dedication involved in establishing the gardens, the lack of available resources, the difference the fresh food makes to families living with a constant threat of malnourishment.

Localised Food Growing in the Sahrawi refugee camps, South West Algeria. - Photo Philip Hittepole - https://scontent-fra3-1.xx.fbcdn.net/hphotos-xta1/v/t1.0-9/12122404_10153708485495844_807527384646669399_n.jpg?oh=06e8b65409137b33eb7f9c73d61c45ee&oe=568576D3
Localised Food Growing in the Sahrawi refugee camps, South West Algeria. – Photo Philip Hittepole – https://scontent-fra3-1.xx.fbcdn.net/hphotos-xta1/v/t1.0-9/12122404_10153708485495844_807527384646669399_n.jpg?oh=06e8b65409137b33eb7f9c73d61c45ee&oe=568576D3


Vegetable growing in the Sahrawi refugee camps, South West Algeria. (Dr. Willem Van Cotthem led the initial UNICEF funded "Family Garden Programme" in the camps) - Photo Philip Hittepole - https://fbcdn-sphotos-c-a.akamaihd.net/hphotos-ak-xaf1/v/t1.0-9/11990694_10153664767110844_6757289647486191923_n.jpg?oh=87d9fd29fd361979c2673d879a450a50&oe=56974400&__gda__=1456167604_68c0ed932731befbf95beedb034ee570
Vegetable growing in the Sahrawi refugee camps, South West Algeria. (Dr. Willem Van Cotthem led the initial UNICEF funded “Family Garden Programme” in the camps) – Photo Philip Hittepole – https://fbcdn-sphotos-c-a.akamaihd.net/hphotos-ak-xaf1/v/t1.0-9/11990694_10153664767110844_6757289647486191923_n.jpg?oh=87d9fd29fd361979c2673d879a450a50&oe=56974400&__gda__=1456167604_68c0ed932731befbf95beedb034ee570
A small child peeks from behind the sacks of dry food distributed in the Laayoune camp, South West Algeria. - Photo: Dominik Sipinski - Article here: http://www.joinmagazine.co.uk/article/a-permanent-crisis-in-the-desert/ - https://scontent-fra3-1.xx.fbcdn.net/hphotos-xft1/v/t1.0-9/11109666_10153449833530844_2918553993613655361_n.jpg?oh=95c08463cb5220695bf56ea0849cf96e&oe=5696E2C0
A small child peeks from behind the sacks of dry food distributed in the Laayoune camp, South West Algeria. – Photo: Dominik Sipinski – Article here: http://www.joinmagazine.co.uk/article/a-permanent-crisis-in-the-desert/
Sahrawi refugee camp. Photo by Olivia Wimmer part of a series entitled "Borrowed Land"  http://olivve.com/work/sahrawi-architecture/ - https://scontent-fra3-1.xx.fbcdn.net/hphotos-xtl1/v/t1.0-9/11951878_10153622287195844_3320971379922172524_n.jpg?oh=d5bc1e59c49a2172174fcbfe52dceb87&oe=568DEB72
Sahrawi refugee camp. Photo by Olivia Wimmer part of a series entitled “Borrowed Land”

Family gardens in the Algerian Sahara desert

Photo credit: Willem Van Cotthem


One of the family gardens in Smara refugee camp

Some people seem to have forgotten Peter KENWORTHY’s 2012-article:



but we didn’t. So, here it is :

The UN says that it seeks sustainability in its work and programmes, that it seeks “integration of the social, economic and environmental dimensions of sustainable development in policy-making at international, regional and national levels”.

And the UN’s Children’s Fund, UNICEF, says on its website that “UNICEF has worked from its founding on nutrition programming aimed at fulfilling every child’s right to adequate nutrition,” because “good nutrition benefits families, their communities and the world as a whole.”

But these principles have seemingly not been applied in the Tindouf refugee camps. Here approximately 150.000 Saharawis have been in a desert exile for 35 years, since their homeland, Western Sahara, was invaded by Morocco.

Over the last 25 years, the UN’s World Food Programme (WFP) has spent many millions of dollars on keeping the Saharawis in the camps from starvation – although malnutrition in the camps is still widespread and WFP funds for the camps are decreasing.

According to the WFP, “opportunities for self-reliance in the harsh, isolated desert environment where the [Tindouf refugee] camps are located are extremely limited, forcing the refugees to rely on international assistance for their survival. Malnutrition rates remain high, with acute malnutrition at a critical level of 18.2 percent, chronic malnutrition at 31.4 percent and underweight at 31.6 percent.”

But until it was abruptly terminated in late 2007, UNICEF ran a successful and seemingly sustainable family garden project in the camps. The project saw 1200 family gardens constructed in extremely adverse agricultural conditions, vegetables and fruit trees being produced by means of minimum water and fertilizer input, using special water-stocking soil conditioners, and agricultural techniques taught to the participating families and school children.

“Any neutral observer will understand that there is a dramatic difference between shipping food aid to the refugee camps for 35 years, as has the WFP, and creating local food production in a sustainable way, as has the UNICEF project,” says Botany Professor Willem Van Cotthem, who was a UN scientific consultant on the gardens project from 2005 to 2007.

Van Cotthem is still puzzled why the UN suddenly ended the project. “The enthusiasm about the successes with the family gardens in the camps was unprecedented,” he says. “All the Saharawi ministers and the President himself expressed their hope that UNICEF would continue that magnificent project until every refugee family had its own garden.”

And the reason for the terminations of the project was not a lack of information of the project’s accomplishments, he insists, nor any misgivings about its achievements. “Staff members of UNICEF, UNHCR and the World Food Programme visited the camps several times to observe the progress made. Medical doctors and consultants of UNICEF repeatedly confirmed that the consumption of fresh food and fruit had a very positive effect on the level of malnutrition.”

Small-scale family gardens that produce fresh food are widely accepted as being an important part of a successful food production, and subsequently on the nutritional intake of desert populations such as in the Tindouf refugee camps, and they are also a cheaper and more sustainable way of supplying food than shipping it from abroad, Van Cotthem insists.

“A growing production of vegetables and fruits forms the embryonic stage of a potential local market development in the camps,” he says. “And training the refugees in agricultural and horticultural techniques, as a group of experts and technicians did, is a rewarding investment in knowledge and skills that is applicable in any future situation, even if the dispute with Morocco gets settled and the refugees return home.”

According to Van Cotthem, the reason given for terminating the project was an Al-Qaeda-executed terrorist attack on a UN building in Algiers that killed over 60 people, including 17 UN staff members – an attack UN Secretary General Ban Ki Moon called an “abjectly cowardly strike.” “And if lack of funds is the reason for stopping the garden project,” says Van Cotthem, “then one cannot understand why a project for sustainable development of local food production is stopped in favour of shipping food.”

And Van Cotthem is adamant that the results of this omission, on top of food aid cutbacks, are and will be disastrous. “Malnutrition will enhance and hunger will be looming. Already in 2007-08 the level of food stocks in the camps was catastrophic. But the international organisations are fully in a position to compensate the reduction in shipped food by offering the Saharawis the chance to develop a maximum number of gardens.”

In the mean time, the Saharawis themselves and private initiatives such as the “Be Their Voice” –programme, which runs small-scale family gardens, have attempted to fill the gap left by the UN. But as the Saharawis are strapped for cash and NGO-driven programmes rely mostly on private donations to a mostly unknown refugee crisis, the capacity and scope of such projects is by no means sufficient.

Read More:

Willem Van Cotthem’s website

The case for Western Saharan independence

How farmers can adapt and survive in a changing climate

Photo credit: Willem Van Cotthem

TC-Dialogue Foundation (Belgium) horticultural project – Oualidia Morocco 2002-07 – testing TerraCottem soil conditioner

Could better soil management reverse global warming?

by Sami Grover


For folks who enjoyed my piece on gardens and carbon sequestration, Peter Bane offered this practical advice on enhancing carbon storage: engineer “soil climaxes”, and lots of them—meaning we need to grow plants, be they cover crops, annual food crops, or perennials, trees and shrubs, and then we need to cut them back before they flower. As plants get cut back, their roots die underground, leaving packets of food for the underground food web. And that food turns into guess what? Soil carbon.

For more on the fascinating interaction between soil and climate, I highly recommend The Soil Will Save Us by Kristin Ohlson. And in the meantime, we’d probably best build some gigantic solar farms too.

Read the full article: Treehugger


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