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Pieter Hoff

Forget geo-engineering and multi-lateral political accords. Could the answer to global warming –not to mention the impending global water and food crises, be found in a device that mimics the effects of bird droppings and is little more complicated than a bucket?

Earlier this year, after seven years and six million Euros in development, Dutch horticulturalist and inventor Pieter Hoff unveiled a gadget he calls the Groasis Waterboxx. It’s an incubator that works without power or irrigation and Hoff reckons it can help save the planet.

“Yes it is a bucket, but an intelligent bucket,” says Hoff. “My ambition is to use it to reforest five billion hectares of poor quality land, reducing levels of carbon in the atmosphere, increasing global food production and rebuilding depleted water tables around the world.”

Global salvation in a bucket may sound like a tall claim, but for all the rhetoric, the Groasis is astonishingly simple and very very plausible. US-based Popular Science magazine is certainly convinced. Last month it declared the Groasis one of the top ten inventions of 2010.

Simple low tech design

It may be an award winner, but the technology in the Groasis couldn’t be simpler because Hoff designed it with no moving parts to keep costs down. So it’s just a ring-shaped plastic container or bucket with a lid that allows saplings or seeds to be planted in the centre opening. The bucket chamber is initially filled with 16 litres of water and there are two holes on the lid that allow it to be topped up by rainfall and condensation.

Near the bottom is a smaller hole with a wick that touches the soil. This allows water to seep out at the rate of about fifty millilitres a day. It runs into the soil, creating a damp water column that the sapling’s roots can follow as it grows

Now 50 mls a day may not sound like much, but according to Hoff, it is a ‘Goldilocks’ amount: neither too much nor too little. If the plants or saplings have more water than 50 mls, they don’t develop their root systems fully and become feeble water junkies, dependent on irrigation for survival.

The water savings per plant are enormous. “A major problem in establishing plants and trees, especially in hot areas is that ninety per cent of precipitation evaporates. A young vine for instance can use up to 1400 litres of water a year and most of that is wasted.” Multiply that figure by thousands or tens of thousands and agriculture in arid areas soon becomes untenable.

One per cent water consumption

In contrast the Groasis uses as little as one per cent of the water used in conventional irrigation. “With the Groasis, water can’t evaporate from the chamber because it has a lid and it cannot evaporate from the ground beneath because it is shaded by the Groasis. So it provides just enough water for plants and saplings to establish themselves with no on-goingcare,” explains Hoff.

It is this shading of the ground that mimics the effects of bird droppings. “In nature seeds aren’t buried they are spread by birds and animals in their droppings and they are sown on top of the soil. The droppings cover the soil, preventing evaporation and creating a small humid patch beneath that encourages the tap root,” says Hoff.

So why, how, could this ‘bucket’ possibly help with global warming? According to Hoff, trees soak up or bind CO2 at an average rate of five tons per hectare per year. “Mankind has cut down roughly two billion hectares of forest in the last two thousand years, and allowed much of it to be grazed by sheep and cattle. This has degraded the quality of land making it hard and less permeable. So when it rains, rather than sinking in, it just runs off.” Studies conducted by NASA have found a link between deforestation in some parts of the world and a lack of precipitation in others.

Reforestation sequesters carbon

As a consequence soils across the world have dried out, making them less receptive to trees. “If we reforest the two billion hectares we have lost, they will absorb 10 billion tons of carbon a year, which coincidentally (and it is a coincidence) is roughly the amount of carbon mankind produces every year using fossil fuels. “

Hoff, who is not a global warming dogmatist and happily lives with the idea that it is not necessarily caused by man even implies that deforestation may have significantly contributed to rising carbon levels.

The main reason forests haven’t regenerated spontaneously is that they face a viability problem in early life. Until trees’ tap roots find what Hoff refers to as the “capillary hang water zone”, (moist soil that lies a couple of meters below the surface), they cant establish themselves. So during the first year or so they are vulnerable. This is what causes huge swathes of land to remain treeless and it is this problem that the Groasis is designed to address.

But what apart from cheapness and huge water savings, does the Groasis add to existing technology? After all there is already highly complex irrigation equipment available that allows farming to be carried out in all sorts of hostile environments. We can already plant trees anywhere if we want to. You might argue that it is the political will, not a clever bucket that is lacking.

Simple, cheap and decentralised

One of its great advantages is that because it is cheap and simple, decisions can be decentralised. If you live on a barren mountainside you can go out and buy a couple of Groases and start growing trees today with no government intervention.

It turns out that bringing marginal land back into productive life won’t be quite as hard as you might imagine says Hoff because surprisingly once they are established, trees can grow pretty much anywhere –including in deserts and on hard rocks .

“Both sand and rock contain sufficient nutrients. Tree roots grow by producing one cell which finds a small moist crack in the rock or soil and then doubles again and again,” explains Hoff. And they are amazingly powerful. Hoff says roots can exert forces of up to 50 kilogrammes per square centimetre which means they can easily grow in rock if they can find water quickly enough. It is even easier for them to grow in the sandy soil of deserts, he says.

The benefits of reforesting poor quality land could be immense argues Hoff. Not only could they sequester enormous amounts of carbon, they could produce substantial amounts food and alter the composition of the soil, making it far more water retentive.

Successful trials

This is all theory so far. But so far it has been trialled successfully in Spain, Morocco and California. In the Morocco tests some trees were grown with the box, while some were grown without, but still watered regularly. In the end, 88 percent of the boxed trees grew up to be strong, while 11 percent were considered weak. With the unboxed trees, however, only 10.5 percent turned out strong, while 89.5 percent died.

But if all goes to plan, there will also be another major beneficiary: Pieter Hoff himself who hopes to sell “billions” of smart with buckets at prices starting at E6 each, which he says he makes one Euro, (roughly one dollar), each. Does he not think this calls into question his enthusiasm and perhaps taints some of his arguments?

While many entrepreneurs might bristle at their integrity being questioned, Hoff takes it easily in his stride. “I am not a puritan ideologue. I am a business man and I am not ashamed to say I hope to be successful, very successful. There’s nothing wrong with making money providing it is done with integrity and honesty. “

Besides, he has invested millions of Euros of his own money in the Groasis and despite the fact that he thinks it is a game-changing invention, there is no guarantee of success. “There are many brilliant inventions that have come to nothing. Invention is just ten per cent. The other ninety per cent is marketing.” ENDS

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