Precision farming may be a fairly exact science these days, but growing plants in space is still a murky one.  Those in agriculture can appreciate the importance of growing food on board a space station or during a mission to Mars, but a new paper in the Botany Letters highlights the challenges scientists still face in this agricultural frontier.

The paper, published by Lucie Poulet and colleagues from the University of Clermont-Ferrand, Auvernge explains that even though plants have successfully been grown in space, long-term effects on growth and reproduction are not well known.

Since the 1960s, experiments conducted in space stations and research rockets have shown that plants can grow normally in microgravity provided factors such as confinement, lack of ventilation and elevated radiation levels are taken into account. However, microgravity can reduce cell growth, alter gene expression and change the pattern of root growth – all aspects which critically affect plant cultivation in space. 

Seeds produced in orbit also seem to have different composition and developmental stages from seeds grown on Earth. As well as affecting the performance and nutritional content of space seeds, this could damage the flavour of plants produced in space, which might become a problem for crews reliant on plant-based diets during long space missions.

Researchers are still seeking technologies for space agriculture that include efficient watering and nutrient-delievery systems, precise atmospheric controls for temperature, humidity and air composition, and low-energy lighting.  Finding the right breeds is also essential; plants with reduced size and high yields are being sought.

Lucie Poulet stated in her paper: “Challenges remain in terms of nutrient delivery, lighting and ventilation, but also in the choice of plant species and traits to favour. Additionally, significant effort must be made on mechanistic modelling of plant growth to reach a more thorough understanding of the intricate physical, biochemical and morphological phenomena involved if we are to accurately control and predict plant growth and development in a space environment.”