Could we grow food on Mars? UNE Sci Flicks chat with Dr Chris Guppy

Published 21 February 2022

For the first UNE Sci Flicks event of 2022, we’re delving into the 2015 film, The Martian, which tells the story of astronaut Mark Watney and his quest for survival while stranded on Mars.

In the film, Mark uses his skills as a botanist to grow his own food and water, and it got us thinking… could this actually be possible?

At the Sci Flicks screening this Thursday 24 February at Armidale’s Belgrave Twin Cinema, UNE Associate Professor in Soil Fertility, Dr Christopher Guppy, and Lecturer in Crop Science, Dr Richard Flavel, will answer this very question in a Q&A session, using current UNE research to help separate the science fiction from the fact.

In the lead up to the event, we spoke to Dr Guppy about the growing conditions on Mars, and whether future research might see crops grown on different planets in the future. Here's what he had to say:


Could we actually grow food on Mars, and hypothetically, how would we go about doing this?

Yes, but not necessarily in the way depicted in the movie. If we were to grow food on Mars, it would most likely need to be done hydroponically initially, using artificial light. Without the protective influence of a thick atmosphere, the radiation from the sun would mutate and damage the crops if grown on the ‘surface’.

What is the soil like on Mars?

The ‘soil’ on Mars is not actually defined as soil, as soil needs to contain some organic matter. Martian soil, for obvious reasons, does not. It is more properly called ‘regolith’. The sandy, red soil depicted in the movie is unlikely to exist. A few centimetres of the surface soil is oxidised, however, when you go further down, it’s likely grey underneath.

Some studies have shown Martian soil simulants hold water better than Earth's soil – why is water retention important when growing crops?

It is actually not just about water retention, but about water release. Clay soils here on Earth hold plenty of water, but they also hold on to it pretty tightly. In contrast, sandy soils, like you may find at the beach, don’t hold onto water very well at all and it drains away quickly. However, if root systems are present they can extract that water pretty well! There is an ideal amount of clay, silt and sand in a soil that both holds on to water and releases it to plant roots efficiently. We call it a ‘loam’. Water retention though, is critical for growing crops, particularly in Australian soils where crops are often grown on stored soil moisture.

How do we achieve optimum soil health for growing crops?

Optimum fertility requires the necessary soil chemistry, physics and biology. This means the soil needs to supply the nutrients, water and biology to encourage plant growth.  Plants do modify the soil environment and make it better, but there are some constraints in soils that even plants can’t overcome.

What work is UNE currently doing in this space?

UNE has many projects in soil health. There is a large and active Soil Carbon group examining how carbon accumulates in soil and how quickly it cycles. There are large projects looking at amendment subsoils to try and increase root activity in soils at depth and increase the volume of soil that plant roots can explore and extract water and nutrients from. We also have many PhD students looking at phosphorus and potassium and nitrogen cycles in soil and trying to increase their availability to plants.

Do you think all of the research that's being done in soil science will mean it will someday be possible to grow our food on other planets?

Absolutely. Soil science is the most important science on the planet!


Event details:

  • When: Thursday 24 February, 6:15pm
  • Where: Belgrave Twin Cinema, Armidale.
  • Who:  Anyone in the community who is keen to watch a great film, and learn the science behind what's being shown on the big screen.
  • Entry: You can purchase tickets via the Belgrave Twin Cinema website.
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