A Martian colony by 2024?
A Martian colony by 2024? mars-one.com

It is possible to grow plants on Martian soil, researchers in the Netherlands have found.

In an experiment conducted over a period of 50 days, at least 14 plant species, including food plants, were grown on artificial Martian and lunar soil provided by Nasa, according to Xinhua.

About 4,200 seeds were planted in 840 pots stuffed with an imitation of Mars and Moon regolith, unconsolidated surface sand of the respective planets. The volcanic soil of Hawaii, and desert sand of Arizona were used for the sand concoction.

The Martian soil mixture was identical to the samples brought from Mars by Viking 1, the first spacecraft to successfully perform its six-year-long mission on Mars.

The unique study was led by Wieger Wamelink, ecologist at Dutch research institute Alterra of Wageningen University.

According to him, Martian soil did unexpectedly well.

"The outcome was quite a big surprise," said Wamelink. "Some species such as rye and cress were already sprouting within 24 hours. Eventually plants on Mars soil were even blossoming. We fertilized them with a brush, with some even seeding. It was exciting to watch. Tomato plants were growing and carrot plants even had small carrots, cress formed seeds."

He added: "We did not know what would happen when we added water to the soil. What turned out is that the Martian soil holds water well, while the moon sand did not."

To the researchers' amazement, all plants germinated in the Martian soil. Rye and cress, the agricultural crops, germinated best, while wild plants germinated badly.

Wamelink's research team found that plants grown on Martian sand did much better than on the nutrient-poor Earth sands extracted from 10-metre-deep layers around the river Rhine.

"I was very surprised when we found out plants grew better in the Mars soil than in the Earth soil. The Earth soil that we used was quite clean, a kind of river soil, relatively poor in minerals. But I didn't expect the Mars soil to produce better plants," Wamelink told Euronews.

However, the lunar soil yielded scanty germination, with poor growth recorded for all the species. Many germinated plants did not last by the end of the experiment. Agricultural crops did not fare well, but after 50 days a few of them including rye, carrot, cress, reflexed stonecrop and red fescue were alive, but not in a very healthy state.

"There are a few reasons for the poor performance on the moon, besides that it does not hold water well," said Wamelink.

"We sent the sand to our lab. Moon sand contains aluminum, which is poisonous for plants. In addition, the soil pH (acidity) is too high. There is not enough acid in the soil. But it would certainly be possible to grow plants on the moon. Only you have to manipulate the sand. This could be done by planting some specific plants absorbing the aluminum from the soil. And acidity can be easily lowered by adding acid," he said.

The recent research on the fertility of Mars-like soil is linked to the "Mars One" project led by Dutch entrepreneur Bas Lansdorp, who is heading a non-profit organisation, Mars One, aimed at building a permanent human settlement on Mars by 2025.

Wamelink wants to continue with the experiment. "We want to see when the plants are safe to eat," the ecologist said.

"In the next phase, we want to grow a tomato. We want to see if it is possible to yield enough to feed people."

Growing tomatoes on Mars could be an uphill task, as Martian soil is expected to be laden with heavy metals which would be taken up by the plant, making it toxic to consume, implying that extra-terrestrial farming will require a lot of sand manipulation.