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The configuration of a biologically active and fertile substrate consisting mainly of Martian regolith to facilitate the growth of edible plants during long-term manned missions to Mars constitutes one of the main challenges in spatial research. Regolith amendment with compost derived from recycled crew effluent crop waste generated by bioregenerative life support systems constitutes a substrate that may contribute to upgrade crew autonomy and long-term survival in space. In this context, the present work aimed to: i) study the geochemical and mineralogical composition of MMS-1 Mars simulant and the physicochemical and hydraulic properties of mixtures obtained by mixing MMS-1 and green compost at varying rates (0:100, 30:70, 70:30, 100:0; v:v); ii) evaluate the potential use of MMS-1 as growing medium of two lettuce cultivars; iii) assess how compost addition may impact on sustainability of space agriculture exploiting local resources. MMS-1 is a coarse-textured alkaline substrate consisting mostly of plagioclase, amorphous material and, to a lesser extent, zeolite, hematite and smectites. Although it can be source of nutrients, it lacks of organic matter, nitrogen (N), phosphorus (P) and sulphur (S), which may be supplied by compost. Both lettuce (Lactuca sativa L.) cultivars were able to grow on all mixtures for 19 days under fertigation. Red Salanova lettuce produced a statistically-greater dry biomass, leaf area and number than green Salanova. Leaf area and plant dry biomass were higher on 30:70 simulant/compost mixture. The shoot/root ratio of plants decreased as simulant in growth substrate increased. Lack of biological fertility and possible salt stress negatively impacted on plants grown in non-amended simulant. Our results show that it is possible to grow crops in Martian simulants adequately amended and fertilized. However, many remaining issue warrant further investigation concerning the dynamics of compost production, standardization of supply during long-term manned missions and representativeness of simulants to real Martian regolith.

The configuration of a biologically fertile substrate for edible plant growth during long-term manned missions to Mars constitutes one of the main challenges in space research. Mars regolith amendment with compost derived from crew and crop waste in bioregenerative life support systems (BLSS) may generate a substrate able to extend crew autonomy and long-term survival in space. In this context, the aim of our work was threefold: first, to study the geochemistry and mineralogy of Mojave Mars Simulant (MMS-1) and the physico-chemical and hydraulic properties of mixtures obtained by mixing MMS-1 and green compost at varying rates (0:100, 30:70, 70:30, 100:0; v:v); secondly, to evaluate the potential use of MMS-1 as a growing medium of two lettuce (Lactuca sativa L.) cultivars; thirdly, to assess how compost addition may impact on sustainability of space agriculture by exploiting in situ resources. MMS-1 is a coarse-textured alkaline substrate consisting mostly of plagioclase, amorphous material and secondarily of zeolite, hematite and smectites. Although it can be a source of nutrients, it lacks organic matter, nitrogen, phosphorus and sulphur, which may be supplied by compost. Both cultivars grew well on all mixtures for 19 days under fertigation. Red Salanova lettuce produced a statistically higher dry biomass, leaf number and area than Green Salanova. Leaf area and plant dry biomass were the highest on 30:70 simulant:compost mixture. Nevertheless, the 70:30 mixture was the best substrate in terms of pore-size distribution for water-plant relationship and the best compromise for plant growth and sustainable use of compost, a limited resource in BLSS. Many remaining issues warrant further investigation concerning the dynamics of compost production, standardisation of supply during space missions and representativeness of simulants to real Mars regolith.

Groundwater contamination is one of the major environmental problems throughout the world. This is partly because groundwater can transport a substance quite easily and even extensively toward a receptor. Agriculture is a weak link in this context since, for example, fresh produce irrigated with low-quality water is a major factor contributing to some human diseases. Apart from pathogenic microorganisms, a gross source of groundwater contamination is by volatile organic compounds (VOCs). In this paper, we present and discuss a monitoring activity of transport processes in the soil-vegetation-atmosphere continuum to evaluate the effectiveness of a sprinkler irrigation system specifically-designed to reduce the COVs’ concentrations in a contaminated site. For phytoremediation purposes, this test site is planted with poplar trees.

Cultivation of vegetables under plastic tunnels is a steadily growing farming system, nevertheless there are concerns about its environmental sustainability. This work tests a new cultivation system based on the application of photo-selective mulching films to the soil combined with beneficial microbes to improve crop yield, save irrigation water and enhance crop irrigation water productivity. A two-year project was carried out in three farms of southern Italy that practice cultivation in greenhouses with different soil characteristics. Photo-selective mulching films (PS) were used alone or in combination with microbial consortia (M) containing beneficial microbes (i.e. antagonistic fungi of the genus Trichoderma, mycorrhizal fungi of the genus Glomus and the plant growth promoting bacterium Bacillus subtilis) and compared with black plastic mulching (B). Soil temperature, soil water content, and irrigation water volumes were continuously monitored for eight cropping cycles including tomato, sweet pepper, lettuce, melon, and kohlrabi. Crop yields were assessed at the end of each cycle. PS films in combination with M significantly increased crop yields with respect to control, with the most positive effects on winter crops. Soil temperature under PS was consistently lower than that under B mulch. All mulching films allowed the saving of irrigation water compared with untreated control, but no difference was detected between PS and B. However, PS increases crop irrigation water productivity (CIWP) compared with B film in 25% of the experimental cases. In conclusion, our results indicate that combining PS films with beneficial microbes in cultivation under plastic tunnel greenhouses promotes crop yield and increases CIWP compared with control in 87.5% and 75% of the study cases, respectively.

Tree crops are representing one of most widespread agricultural systems in Mediterranean regions, thus contributing in a substantial way to the economy and productivity of primary sectors of the countries interested. Besides the aspects concerning their economical relevance, tree crops like vineyards, olive and orange orchards are also typical elements of the Mediterranean landscape, and their ecological role has been recently revitalised in consideration of their function as carbon sinks for the Kyoto agreement. The environmental and economical sustainability of these agricultural systems in arid and semi-arid zones has to cope with the availability and management of water resources for irrigation. During recent years there has been a substantial progress in understanding the evolution of evapotranspiration processes in cropping systems, and detailed models and measurement techniques have been set-up for describing the mass and energy exchanges in the soil-plant- atmosphere continuum. However, due to the complexity of rooting systems and aerial parts further steps are needed for a full comprehension of hydrological processes in tree crop systems, with special regard to water stress conditions. Within the research project P.R.I.N. 2008 “ Assessment of mass and energy fluxes for the irrigation management of Mediterranean tree crops ” different techniques for measuring evapotranspiration fluxes in tree crops will be developed and tested, from innovative methodologies based on remote sensing observations to in-situ observations (xylem-flow measurements and micro-meteorology). These data-sets have be interpreted by means of physical approaches, with a modelling perspective of the observed processes.