Russian researchers have proposed to use a fully oxidised wheat straw to replenish mineral elements in the substrate poovarodom life support systems in space. The authors found that this approach allows us to provide the plants with necessary nutrients and increase their productivity. The study is published in the journal Life Sciences in Space Research.
Bio-engineering closed life support system (LSS) allow you to maintain favourable conditions for life on other planets or in long-term space flights without the need for delivery of vital resources. In such systems, the cycle established all the necessary connections: oxygen, water and food.
To get energy and carbohydrates in DLC people can from wheat. The problem is that a large portion of the biomass of this plant not used for food. Because of this, in recent experiments with WCS — BIOS-3 in Russia and “Moon Palace” in China — the straw of wheat was one of the main vegetable waste. It is difficult to recycle because of the high content of lignin — the “stiff” plant cells. Because of this, it is extremely difficult to use minerals for plant nutrition.
In closed life support systems vegetable waste can be used to create pokvartirnogo of the substrate. Earlier experiments showed that this substrate is able to support plant life if the balance is maintained between speed of consumption of mineral elements by plants from their substrate and recovery of microorganisms from plant residues. However, DLC such balance is difficult to control due to characteristics of the substrate.
Scientists from the Institute of Biophysics, Krasnoyarsk scientific center, SB RAS invited to apply fully oxidized to soluble mineral elements of wheat straw as a mineral additive to the soil substrate. This method allowed to increase the productivity of plants and to create a new strategy for the processing of vegetable waste in closed life support systems.
Before adding straw Pochvovedenie substrate, it was oxidized to assimilable forms with the help of electric current in an aqueous solution of hydrogen peroxide. The researchers analyzed the straw with different degree of decomposition. It turned out that not enough oxidized straw reduces the yield of cultivated plants in nine times. According to the researchers, this occurs because of the formation of oxidized reaction products that inhibit the growth of crops. And the more oxidized was the straw, the higher the concentration of such substances in products of oxidation. If wheat straw is oxidized completely, adding it increased productivity three times. It’s a tieANO with plenty of available nitrogen, potassium, phosphorus and sulfur in the substrate.
This approach to creating the long-running DLC creates another problem. For the oxidation of this quantity of straw required a lot of hydrogen peroxide, to produce which is not just in space conditions. Moreover, the addition of a fully oxidized straw can damage the basis of pokvartirnogo substrate, as it consists of a mixture of vegetable wastes in various stages of decomposition.
“Now we are thinking to divide the straw into two pieces: one can be fully mineralizate hydrogen peroxide, and the other added to the substrate to maintain its structure. Implementation of this strategy will be the aim of future research for improving the root nutrition of plants cultivated on reused substrates in life support systems,” — said the lead author, researcher at the Institute of Biophysics KSC of SB RAS Vladimir Velichko.
