学进去

The second experiment on how to grow crops on Mars and moon soil simulant(模拟装置)has given a surprising outcome. As a result of what the researchers of Wageningen University & Research center in the Netherlands learned from their first experiment, they were able to grow ten different crop species. Tomatoes, peas, rye, garden rocket, radish and garden cress were harvested.

A few improvements have been made since the first experiment. Researcher Wieger Wamelink said, “We used trays instead of original small pots and added organic material (fresh cut grass) to the Mars and moon soil simulant. This solved the problem we had with watering in the first experiment and also added manure(肥料)to the soils.” In particular, the crop growth on the moon soil simulant showed improvement. While in the first moon soil experiment most plants died, in the next round they flourished, and the researchers could harvest from the same species as on the Mars soil simulant and the Earth potting compost(混合肥料)control.

The production of biomass(生物量)on the Mars soil simulant was lower than on Earth control, but it was a minor difference and caused by one of the trays that showed less growth. It was also not statistically different from the Earth control. “That was a real surprise to us,” comments Wamelink. “It shows that the Mars soil simulant has great potential when properly prepared and watered. The biomass growth on the moon soil simulant was less than on both other soils, about half of the biomass. Only the spinach(菠菜)showed poor biomass production.”

Although the researchers harvested several eatable crops, they did not eat them. The soils contain heavy metals like lead, arsenic and mercury and also a lot of iron. If the components become available for the plants, they may be taken up and find their way into the fruits, making them poisonous. Further research on this is necessary and that is one of the reasons why a crowdfunding(众筹)campaign has been started to finance the third experiment that will be all about food safety. If the crops prove to be safe enough to eat, the funders will be invited for dinner where a ‘Martian meal’ will be served that includes the harvested crops; at least for those who dare!