2012-06-20 16:42:13    CRIENGLISH.com      Web Editor: yangyang66

With the fast development of urbanization in the world especially in China, megacities such as Beijing and Shanghai will face the challenges of transportation, water and land for food, especially vegetables. Against this background, one company in Sweden has developed the innovative concept of urban agriculture grown aboveground using treated wastewater. CRI’s Chen Xuefei in Stockholm has an exclusive interview with Hans Hassle, CEO of Plantagon, an urban agricultural company in Sweden.
Q: When we talk about agriculture, we always think of rural areas. When you talk about urban agriculture, what does this mean? What kind of crops are you referring to?
A: Urban agriculture refers to the industrial production of food inside city areas or urban areas and normal vegetable production you can very well grow in urban agricultural systems.
Q: How can urban agriculture be applied to China’s megacities?
A: Especially in China where you see the rapid development of huge cities, we will see a future problem with transportation costs. The distance from the farmer to the consumer will continue to be extended. Where are we going to produce enough food? And that is the second reason. Because there isn’t enough land in the nearby area. The free land will not be enough. That is the second reason for urban agriculture. We have to find how it will be possible to extend growable cultivation areas in the whole world. And this will, of course, affect China very much.
Q: Do you mean growing aboveground?
A: Exactly. As soon as you talk about urban agriculture, you always talk about using as little land as possible and producing as much food as possible with as little energy and water consumption as possible. But if we stick to the first part, using very little land and growing a lot of food, then you have to grow the food vertically. So you have to build vertical greenhouses or you have to use facade systems on existing buildings, because we can’t use the ground. The footprint on the ground has to be minimal.
Q: Are there climate restrictions when doing this?
A: For normal technology, there will be climate restrictions, because, for example, in tropical areas, you have to protect the crops from pollution and other things in cities. And then you also can control the climate in the system. So start from working with closed systems. But once you start from working with closed systems, you can control the climate there. In that sense, you can grow it anywhere in the world, even though it might sound a little strange that you grow it in a tropical area.
Q: What about the cost?
A: The cost is much higher than normal. On the other hand, we don’t use so much land. When you transport crops between two cities, you don’t need the middlemen cost. You cut away the transportation and other costs that you would have as a normal grower, so even if you have to invest more, in a vertical farm inside the city, you get that money back with a distant transport model. You also save a lot of money where the customers are.
About 60 percent of the total cost goes from the grower to the consumer, the middleman’s cost. And as we grow where the consumers are, we can sell directly to the consumers. So when you look at the payback time, it is very sound. The payback time is about five to seven years.
Q: If you don’t use soil, then how do you grow?
A: We grow in liquid and then we use a certain kind of stone. The stone absorbs water the same way that soil does. Instead of using soil, we use a very clean stone. It is nutritious. For your question about how we can ensure the food is good, it is because we can control the system. There is no dirty water coming in from the outside.
Everything that goes in from the outside into the greenhouse is clean. Everything coming out of the greenhouse is also very clean. So we use gray water, and then we clean the gray water and put it into the greenhouse. So nothing is coming without control into the system. That is why we know that it is very healthy food. Q: When you say that you use gray water, is that part of a circular economy?
A: Yes, that’s right.