Mars Exchange
Food for Mars: Rye Harvest

Food for Mars: Rye Harvest

by Natasha Schön on Monday, 17th August 2015 in Food for Mars, People, Wieger Wamelink

The rye has finally been harvested. It was looking overripe, but the seeds were still hanging on to the head of the plant. Well done seeds and thanks, also on behalf of the writing, photographing and filming journalists. Also, the rye plants had a pleasant surprise ‘prepared’ for us. This is the eighth post in a blog series about experiments conducted by a team of ecologists and crop scientists of Wageningen UR. The goal of these experiments is a proof of concepts for providing the first (human) Martians with ‘own-grown’ fresh food. Find the links to our first seven blog posts below!

Plants are grown in trays in this experiment and they have small holes in them to allow water to leak out if it is given in quantities that are too large. However, in the first experiment the small pots were often too dry, so we did not want any water to be lost. Loss of water would also possibly mean loss of nutrients and heavy metals. Loss of nutrients we do not want, but the latter, heavy metals, might be okay (and avoid the problems heavy metals could cause) but, as the effect of heavy metals is still part of the experiment, to lose them would also be a problem. Holes in a tray can also be used by roots, since they tend to grow through them when seeking nutrients. With no special measures they would grow into the table, thus influencing the outcome of the experiment. To prevent all this there is simple solution; we put the trays in a second tray without holes which prevents water from leeching and roots from growing into the tablecloth. For a long time I did look underneath to review what was going on in the space between the trays. Last week I was expecting lots of roots to be dangling from the bottom of the first tray but, much to my surprise, there was nothing of the kind. There are only a very small number of roots poking through the bottom of the trays so, apparently, the trays are wet enough and there is no real shortage of nutrients, both of which are good news.

It seems that there can be no blog post without peas. When I was at the International Association of Vegetation Science (IAVS) conference in Brno to present the first experiment, I visited the Mendel museum. The Augustinian friar Mendel was a monk who experimentally proved the way the heritage of genes works (AA*aa=Aa; Aa*Aa=AA+2Aa+aa, as nowadays taught in every secondary school biology lesson) in the nineteenth century. Clearly, he also loved peas because they featured in many of the experiments he conducted. To spread the pollen of the plants he used a paint brush - just as we did. So not much has changed in 150 years; although his brush will have contained animal (pig) hairs, and ours has artificial nylon hairs.

Back to the rye and its surprise. Many plants have now formed new shoots, something they do when they have enough space and nutrients (which is something that all grasses can do - in principle). We therefore had to be very careful during the harvest; we did not want to clip the new shoots. This means that, if the experiment will last long enough, we could have a second harvest from the rye. If we are able to secure funding to continue the experiment for even longer we might even have more than two harvests.

Story contributed by Wieger Wamelink, a Senior Ecologist at Alterra. 

More Information:

Roots dangling out of the first tray, exploring the space in between the two trays for water and nutrients.

Drawing of the peas Mendel worked with, using a paint brush just as we did (Mendel museum Brno, Czech-republic).

The harvested Rye in the bag from the Mars soil simulant before they go in the ‘oven’ to dry at 28 0C (82.4F).

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