AGRONOMIC STRATEGIES FOR SUSTAINABLE MANAGEMENT OF LOW-INTENSIFICATION HERBACEOUS CROPPING SYSTEMS

Climate change and population growth are putting a strain on the agricultural sector, which must increase productivity but at the same time find sustainable solutions. The domestication of wild species can prove important as a tool for mitigating climate change because they would be exploited in areas close to desertification or in any case marginal, bringing environmental benefits and also a valuable food supplement to meet the needs of the growing population. In particular, in Mediterranean environments, a halophyte, Crithmum maritimum L., is establishing itself, recently returned to the fore after being used by the maritime populations of the Mediterranean as a spontaneous plant. Sea fennel has shown adaptability in marginal soils and those subjected to stress such as salt intrusions and high temperatures, typical environmental issues of Mediterranean coastal areas. The growing interest in C. maritimum L. is motivated by the numerous uses: food, pharmaceutical, cosmetic, fodder and environmental (green roof). Crithmum maritimum L. can therefore be considered an emerging horticultural crop: the horticultural sector must have environmental sustainability as its objective and therefore optimize the distribution and choice of inputs to achieve an economic rationalization of resources but above all to have a lower environmental impact. In this perspective, biostimulants are recording a significant increase in use: according to the definition of Kauffman et al. (2007) they are materials, other than fertilisers, that promote plant growth when applied in low quantities so some studies have highlighted an improvement in the quality of the products and a support to the metabolism of the plant to defend itself from abiotic stress thus avoiding the administration of chemical inputs. Microbial biostimulants can be applied during the germination phase of the seeds and subsequently also in open fields where they are able to create a symbiosis in the root system of the plants and therefore be a sustainable agro-environmental solution. However, in the scientific literature we find fluctuating efficacy of the applications of biostimulants in the agricultural sector because they depend on the species and the pedoclimatic conditions. This PhD aims to evaluate the effects of microbial biostimulants on root biometric parameters (dry weight, lenght, diameter and number of tips) C. maritimum L. in the post-seed germination phases and in the phenological phases of pot cultivation of plants produced from seedbeds and prior to the transplantation phase in the field, therefore in incubator and greenhouse, two different growth environments with controlled parameters (light and temperature) to produce plant propagation material of two populations of C. maritimum L. Following the experimentation conducted in the two different controlled environments, the work of this PhD was concentrated in the open field with the administration of the biostimulant that performed best in a controlled environment in the year of transplantation of plants of two populations of C. maritimum L., the same ones studied in the greenhouse and in the incubator: in this case the study was carried out on the epigeal biomass through destructive (fresh and dry weight) and non-destructive (nutritional status detected indirectly with SPAD units) measurements. The results obtained may implement knowledge of the cultivation protocol of Crithmum maritimum L. subjected to low levels of cultivation.