VOA科学技术2024--Scientists Explore How to Grow Crops on Mars

For future humans to survive long periods on Mars, growing food on the planet is a must.

It would be too costly¹ and risky² to rely upon rocket deliveries to meet the food needs of colonists³. With this in mind, scientists are exploring ways to improve space farming.

At Wageningen University & Research in the Netherlands, researchers work in a controlled greenhouse. They have identified a way that could improve crop production in simulated Martian soil, with different crops grown together. The method is called "intercropping." It was first invented by ancient Maya farmers in what is now Central America.

In their experiments, the researchers grew cherry tomatoes, peas and carrots together in small, round containers called pots. Tomatoes grown in this way produced about double the amount of tomatoes grown alone - or "monocropped" - in the same simulated Martian soil. The tomatoes were also bigger. They flowered and matured earlier, gave more fruit per plant and had thicker stems.

The amounts of peas and carrots did not increase with intercropping.

Rebeca Gon?alves is an astrobiologist and lead writer of the study published on Wednesday in the publication PLOS ONE. She said the research is the first time the intercropping technique was used in space soil.

"And the fact that it worked really well for one out of the three species was a big find, one that we can now build further research on," Gon?alves added.

The crops were grown in simulated Martian regolith, a soil with no organic matter. Created by researchers from the American space agency NASA, it is a near-perfect physical and chemical match to real Martian soil.

The researchers added useful bacteria and nutrients⁵. They also controlled the gases, temperature and humidity inside the greenhouse to match conditions expected in a Martian greenhouse.

For now, human bases on Mars are only seen in movies. But NASA, for example, is developing ways to send people to Mars in the 2030s.

"Mars is really far away. A flight now would take about nine months. If you want to live there as humans, you will have to grow your own crops at the site," said study co-writer Wieger Wamelink. He is a plant ecologist at Wageningen and head of B.A.S.E., a company that develops lunar and Martian greenhouses.

"Flying in food is very costly and also vulnerable... Our main goal is to use as much as possible from the resources at the site," he added.

Intercropping involves growing plants with properties that could help each other grow. The method makes the best use of resources including water and nutrients.

The researchers said the tomato plants in intercropping may have benefited from being close to the pea plants. That is because the peas are good at turning nitrogen from the air, with the help of bacteria introduced into the soil, into an important nutrient⁴.

The carrots produced fewer crops from intercropping and the peas had no change, Gon?alves said.

"It is very important how you select the crop species that you combine, because the tomato did profit from the peas, but the carrot most certainly did not. This was probably due to lack of light. The tall tomato and pea plants did out-compete the carrot by taking light from it," Wamelink added.

Overall, the tomatoes, peas and carrots grew well, though not as well as in Earth soil in the same greenhouse.

Words in This Story

simulate - v. to look, feel, or behave like

mature - n. having or showing the mental and emotional qualities of an adult

stem- n. the main long and thin part of a plant that rises above the soil and supports the leaves and flowers

species - n. group of animals or plants that are similar and can produce young animals or plants

site - n. the place where something is, was, or will be located

vulnerable - adj. easily hurt or harmed physically⁶, mentally, or emotionally

profit - v. the advantage or benefit that is gained from doing something

1 costly   

adj.昂贵的，价值高的，豪华的

参考例句：

• It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
• This dictionary is very useful,only it is a bit costly.这本词典很有用，左不过贵了些。

2 risky   

adj.有风险的，冒险的

参考例句：

• It may be risky but we will chance it anyhow.这可能有危险，但我们无论如何要冒一冒险。
• He is well aware how risky this investment is.他心里对这项投资的风险十分清楚。

3 colonists   

n.殖民地开拓者，移民，殖民地居民( colonist的名词复数 )

参考例句：

• Colonists from Europe populated many parts of the Americas. 欧洲的殖民者移居到了美洲的许多地方。 来自《简明英汉词典》
• Some of the early colonists were cruel to the native population. 有些早期移居殖民地的人对当地居民很残忍。 来自《简明英汉词典》

4 nutrient   

adj.营养的，滋养的；n.营养物，营养品

参考例句：

• Magnesium is the nutrient element in plant growth.镁是植物生长的营养要素。
• The roots transmit moisture and nutrient to the trunk and branches.根将水分和养料输送到干和枝。

5 nutrients   

n.（食品或化学品）营养物，营养品( nutrient的名词复数 )

参考例句：

• a lack of essential nutrients 基本营养的缺乏
• Nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》

6 physically   

adj.物质上，体格上，身体上，按自然规律

参考例句：

• He was out of sorts physically,as well as disordered mentally.他浑身不舒服，心绪也很乱。
• Every time I think about it I feel physically sick.一想起那件事我就感到极恶心。