Search Results (5)

Long-term human residence on the Moon is an inevitable trend in lunar exploration, necessitating the development of Bioregenerative Life Support Systems (BLSSs). In BLSSs, plant cultivation serves as the core functional unit, requiring substantial amounts of cultivation substrates. Lunar soil has potential as a cultivation substrate, but its suitability for plant growth must be improved to meet life-support requirements. As a fine-grained, organics-free, in situ resource, lunar soil’s high compaction significantly restricts crops’ root access to oxygen, water, and nutrients. While the addition of organic solid waste—a byproduct of BLSSs—could alleviate compaction, issues such as salinization, incomplete decomposition, and the presence of pathogens pose risks to crop health. In this study, we introduced earthworms into wheat cultivation systems to gradually digest, transfer (as vermicompost), and mix solid waste with a lunar soil simulant substrate. We set five experimental groups: a positive control group using vermiculite (named as V) as the optimal growth substrate, a negative control group using pure lunar soil simulant (LS), and three treatment groups using lunar soil simulant with solid waste and 15 (LS+15ew), 30 (LS+30ew), and 45 (LS+45ew) earthworms added. Our results demonstrated significant improvements in both compaction (e.g., bulk density, hydraulic conductivity) and salinization (e.g., salinity, electrical conductivity), likely due to the improved soil aggregate structures, which increased the porosity and ion adsorption capacity of the soil. Additionally, the microbial community within the substrate shifted toward a cooperative pattern dominated by significantly enriched plant probiotics. Consequently, the cultivated wheat achieved approximately 80% of the growth parameters (including production) compared to the control group grown in vermiculite with nutrient solution (representing ideal cultivation conditions), indicating sufficient nutrient supply from the mineralized waste. We can conclude that the earthworms “complementarily” improved the lunar soil simulant and organic waste by addressing compaction and salinization, respectively, leading to comprehensive improvements in key parameters, including the microbial environment. This study proposes a conceptual framework for improving lunar soil for crop cultivation, and it innovatively introduces earthworms as a preliminary yet effective solution. These findings provide a feasible and inspiring foundation for future lunar agriculture. Full article

Mars exploration will foresee the design of bioregenerative life support systems (BLSSs), in which the use/recycle of in situ resources might allow the production of food crops. However, cultivation on the poorly-fertile Mars regolith will be very challenging. To pursue this goal, we grew potato (Solanum tuberosum L.) plants on the MMS-1 Mojave Mars regolith simulant, pure (R100) and mixed with green compost at 30% (R70C30), in a pot in a cold glasshouse with fertigation. For comparison purposes, we also grew plants on a fluvial sand, pure (S100) and amended with 30% of compost (S70C30), a volcanic soil (VS) and a red soil (RS). We studied the fertility dynamics in the substrates over time and the tuber nutritional quality. We investigated nutrient bioavailability and fertility indicators in the substrates and the quality of potato tubers. Plants completed the life cycle on R100 and produced scarce but nutritious tubers, despite many critical simulant properties. The compost supply enhanced the MMS-1 chemical/physical fertility and determined a higher tuber yield of better nutritional quality. This study demonstrated that a compost-amended Mars simulant could be a proper substrate to produce food crops in BLSSs, enabling it to provide similar ecosystem services of the studied terrestrial soils. Full article

Higher plants will play a key role in human survival in Space, being able to regenerate resources and produce fresh food. However, the creation of a fertile substrate based on extra-terrestrial soils is still a challenge for space cultivation. We evaluated the adaptability of soybean (Glycine max (L.) Merr.) cultivar ‘Pr91M10′ to three substrates, the Mojave Mars regolith Simulant MMS-1, alone (R100), and in a mixture with blond sphagnum peat at two different volumes, 85:15 (R85P15) and 70:30 (R70P30), in plants directly sown on the substrates or transplanted after sowing on peat. The low pH of peat (4.34) allowed the mitigation of the alkalinity of the Mars regolith simulant (pH 8.86), lowering the initial pH to neutral (6.98, R85P15), or subacid to neutral (6.33, R70P30) values. Seed germination reached the highest percentage in the shortest time in the mixture of regolith simulant with 15% of peat. The cultivation substrate did not affect the plant growth and nutritional status. However, a significant interaction between the substrate and planting method was found in several growth parameters, with the highest positive effects observed in plants resulting from direct sowing on the regolith mixture with peat. Full article

The realization of manned missions for space exploration requires the development of Bioregenerative Life Support Systems (BLSSs) to make human colonies self-sufficient in terms of resources. Indeed, in these systems, plants contribute to resource regeneration and food production. However, the cultivation of plants in space is influenced by ionizing radiation which can have positive, null, or negative effects on plant growth depending on intrinsic and environmental/cultivation factors. The aim of this study was to analyze the effect of high-LET (Linear Energy Transfer) ionizing radiation on seed germination and seedling development in eye bean. Dry seeds of Dolichos melanophthalmus DC. (eye bean) were irradiated with two doses (1 and 10 Gy) of C- and Ti-ions. Seedlings from irradiated seeds were compared with non-irradiated controls in terms of morpho-anatomical and biochemical traits. Results showed that the responses of eye bean plants to radiation are dose-specific and dependent on the type of ion. The information obtained from this study will be useful for evaluating the radio-resistance of eye bean seedlings, for their possible cultivation and utilization as food supplement in space environments. Full article

Ultraviolet (UV) is a component of the solar radiation with a wavelength in the range of 100 ≤ λ ≤ 390 nm that is almost entirely shielded by the terrestrial atmosphere, but not in space. The effects of UV-C (100 ≤ λ ≤ 280 nm) on plants mainly depend on: (i) the applied UV-C radiation dose and quality, (ii) the different plant species and varieties used, and (iii) the phenological phase of irradiated plants. UV-C radiation can be extremely dangerous also at low exposition times. On the other side, considering that terrestrial plants under sunlight are naturally exposed to low doses of UV-C, the question is how much UV-C could be beneficial for plants cultivated in space, in relation to (i) protection of plants from pathogens, (ii) increase of the concentration of important dietary supplements, and (iii) regulation of some physiological processes. The research on UV-C should be more addressed to better evaluate the damages and benefits in UV-C-exposed photosynthetic organisms, involving plants useful for Bioregenerative Life Support Systems (BLSSs). Full article