• Energy Research

Water deficit limiting yields is one of the negative aspects of climate change. However, this applies particularly when emphasis is on biomass production (e.g. for field crops), but not necessarily for plants where quality, not quantity is most relevant. For grapevine development, mild water stress occurring during specific phenological phases is an important factor when producing good quality wines. It induces the production of anthocyanins and aroma precursors and then could offer an opportunity to increase winegrower's income. A multidisciplinary study was carried out in Campania region (Southern Italy), an area well known for high quality wine production. Growth of Aglianico grapevine cultivar, with a standard clone population on 1103 Paulsen rootstocks, was studied on two different types of soil: Calcisols and Cambisols occurring along a slope of 90 m length with 11% gradient. The agro-hydrological model SWAP was calibrated and applied to estimate soil-plant water status during three consecutive seasons (2011-2013). Crop water stress index (CWSI), as estimated by the model, was related to leaf water potential, sugar content of grape bunches and wine quality (e.g. content of tannins). For both soils, the correlations between quality measurements and CWSI were high (e.g. - 0.97** with sugar; 0.895* with anthocyanins in the grape skins). The model was also applied to explore effects of future climate conditions (2021-2051) obtained from statistical downscaling of Global Circulation Models (AOGCM) and to estimate the effect of the climate on CWSI and hence on grape quality. Effects of climate change on grape quality indicate: (i) a resilient behavior of Calcisol to produce high quality wine, (ii) a good potentiality for improving the quality wine in Cambisol. The present study represents an example of multidisciplinary approach in which soil scientists, hydro-pedologists, crop modellers, plant physiologists and oenologists have integrated their knowledge and skills in order to deal with the complex interactions among different components of an agricultural system.

Maize is a crucial global commodity, which is used not only for food, but also as an alternative crop in biogas production and as a major energy-supply ingredient in animal diets. However, climate change is jeopardizing current maize production due to its direct impact on weather instability and water availability or its indirect effects on regional climate suitability loss. Hence, new areas for sweet maize cultivation should be considered in the future. Therefore, this study focuses on the possibility of producing maize in a challenging environment in Southern Italy considering rainfed cultivation and two irrigation regimes (full and deficit). The experiment was conducted during two subsequent growing seasons under semi-arid Mediterranean climate conditions. The overall results indicated a significant difference in biomass and yield between irrigated and non-irrigated treatments, and between full and deficit irrigation. Sweet maize cultivated under deficit irrigation gained less biomass than under full irrigation and its development and fruit maturation were delayed. Under deficit irrigation, the plants gave lower yields and a higher percentage of the panicle weight consisted of kernels. Irrigation water productivity was higher for deficit than for full irrigated treatment. These findings indicate the feasibility of sweet maize production in semi-arid areas of Southern Italy using adaptive agricultural strategies including deficit irrigation and controlled water stress. Given the importance of maize production, understanding of maize growth and productivity in a challenging environment may support future agricultural programming and thereby contribute e to mitigation of the direct and indirect effects of climate change.

Given its high biomass and plasticity, Arundo donax L. is a promising ligno-cellulosic crop for cultivation in marginal lands in temperate climates. In order to test for adaptation to salinity, growth parameters of several A. donax clones were evaluated under two salt regimes in hydroponics. Mild NaCl stress (50 mM NaCl, 5.6 mS cm−1 EC, for 10 days) failed to discriminate between ecotypes, while a more severe NaCl treatment (150 mM, 18.8 mS cm−1 EC, for 21 days) enabled the identification of ecotypes maintaining plant growth under high salinity. Among several biometric parameters, 4th leaf width, and shoot and root DW consistently highlighted differences between ecotypes. Gas-exchange parameters also responded to severe NaCl treatment, while the photosystem efficiency was good, regardless of treatment. The results confirm that A. donax can be considered moderately tolerant to NaCl stress, with variation between ecotypes. Our screening protocol identified ecotypes with higher biomass production under severe NaCl treatment and can be useful for preliminary evaluation of NaCl tolerant clones for increasing productivity under salinity. The detected inter-ecotype variability could also be investigated to identify suitable clones for different environments.

The soil salinity increase in the Mediterranean basin is one of the consequences of the climate change. The aim of this study was to evaluate the adaptability of giant reed (Arundo donax L.) to salinity, in conditions of higher temperatures, in order to hypothesise the future use of giant reed under these conditions. The trial was carried out in pots under a permanent metal structure, open on the sides and with a clear PE on the top. Four levels of soil salinity in the range 3.3-15.5 dS m(-1) were imposed. The stem number of the most stressed treatment was about 45% lower than the control and also the stem height was lower than in all other treatments. The green and yellow leaf number decreased as the soil salinity increased, and their sum was significantly lower in the two most stressed treatments. Osmotic potential of the leaf sap was not affected by salinity. Leaf water potential and stomatal conductance in the saline treatments were lower than in the control. Assimilation rate showed similar pattern of stomatal conductance. Intrinsic WUE remained almost stable until July and increased during August under the most stressful conditions. PSII photochemistry was not affected by soil salinity. Biomass yield was not different from the control until to soil ECe 12.0 dS m(-1): only the most stressed treatment (15.5 dS m(-1)) caused yield losses (50%). Tolerance threshold to salinity was 11.2 dS m(-1) and the relative yield losses were 11.6% per dS m(-1).