Root water conductivity of some herbaceous species.

In this study, the values of water conductivity of roots are reported for eleven crops and grapevine. For some crops, two methods (pressure chamber and transpiration method) were compared. The effects of salt and water stress were evaluated on different crops , as the effect of chloride mercury treatment, nitrogen deprivation and the interactive effects of salt, water, nitrogen and mercury stress. Root water conductivity was evaluated, for almost all the crops, during the whole plant cycles. The transpiration method always showed values of root water conductivity higher than the pressure chamber. In almost all the species, the mercury chloride reduced root water conductivity during all the plant cycle. Nitrogen deprivation and salt stress induced higher root water conductivity reduction than mercury stress. Water stress induced also a reduction but its effect on root water conductivity was lower than that of nitrogen and salt stress. Mercury chloride treatment did not show any effect on nitrogen and salt stressed plants, while in the water stressed plants its effect was additiv

The Ecoremed protocol for an integrated agronomic approach to characterization and remediation of contaminated soils

Definition of a site as contaminated: Problems related to agricultural soils Massimo Fagnano.......... pp. 1-5 Geography of soil contamination for characterization and precision remediation of potentially contaminated sites Giuliano Langella, Antonietta Agrillo, Angelo Basile, Roberto De Mascellis, Piero Manna, Pierpaolo Moretti, Florindo Antonio Mileti, Fabio Terribile, Simona Vingiani.......... pp. 6-15 Assessing the bioavailability of potentially toxic elements in soil: A proposed approach Claudia Rocco, Diana Agrelli, Maria Tafuro, Antonio Giandonato Caporale, Paola Adamo.......... pp. 16-22 Use of the native vascular flora for risk assessment and management of an industrial contaminated soil Donato Visconti, Nunzio Fiorentino, Adriano Stinca, Ida Di Mola, Massimo Fagnano.......... pp. 23-33 Assisted phytoremediation for restoring soil fertility in contaminated and degraded land Nunzio Fiorentino, Mauro Mori, Vincenzo Cenvinzo, Luigi Giuseppe Duri, Laura Gioia, Donato Visconti, Massimo Fagnano.......... pp. 34-44 Bioassays for evaluation of sanitary risks from food crops cultivated in potentially contaminated sites Luigi Giuseppe Duri, Nunzio Fiorentino, Eugenio Cozzolino, Lucia Ottaiano, Diana Agrelli Massimo Fagnano.......... pp. 45-52 Responses of bacterial community structure and diversity to soil eco-friendly bioremediation treatments of two multi-contaminated fields Valeria Ventorino, Vincenza Faraco, Ida Romano, Olimpia Pepe.......... pp. 53-58 Monitoring and modelling the role of phytoremediation to mitigate non-point source cadmium pollution and groundwater contamination at field scale Mario Palladino, Paolo Nasta, Alessandra Capolupo, Nunzio Romano.......... pp. 59-6

Tecniche di gestione della fertilità del suolo in una coltura di pomodoro.

Due tipi di sovescio (favino puro e favino + avena) con due epoche di interramento (inizio aprile e fine aprile) in combinazione fattoriale, sono stati confrontati in una azienda sperimentale della Campania, per valutare gli effetti sulla produzione di pomodoro. Dai primi risultati, si può evidenziare come la fertilità residua del terreno, dovuta alla precessione di leguminose, è stata sufficiente a sostenere almeno in parte le produzioni di pomodoro (311 q ha-1). Gli apporti di N sono stati più alti nel caso del sovescio di favino puro e con l’interramento tardivo: 72 e 142 kg ha-1 di N per il favino e 45 e 80 kg ha-1 di N per il sovescio misto, rispettivamente nelle due epoche di interramento. Il rapporto C/N delle biomasse è stato più alto nel caso del sovescio misto e dell’interramento tardivo. Dai dati ottenuti dopo l’interramento dei diversi tipi di sovescio, appare evidente come la presenza della graminacea ha depresso le produzioni, a causa del minore apporto e della più bassa disponibilità di N minerale (438 e 346 q ha-1 rispettivamente con il sovescio di favino e di favino+avena). Non ha avuto effetti sulla produzione il ritardo di circa 20 giorni dello sfalcio e dell'interramento delle colture da sovescio (398 e 386 q ha-1 rispettivamente per il sovescio precoce e tardivo)

Potential role of compost and green manure amendment to mitigate soil GHGs emissions in Mediterranean drip irrigated maize production systems

Organic fertilization can preserve soil organic matter (SOM) and is foreseen as an effective strategy to reduce green house gases (GHGs) emissions in agriculture. However, its effectiveness needs to be clarified under specific climate, crop management and soil characteristics. A field experiment was carried out in a Mediterranean drip irrigated maize system to assess the pattern of soil CO2 and N2O fluxes in response to the replacement of a typical bare fallowemaize cycle under urea fertilization (130 kg N ha1 y1) (CONV) with: (i) bare fallow-maize cycles under two doses of compost (COM1 and COM2, 130 and 260 kg N ha1 y1, respectively) and (ii) a vetch-maize cycle, with vetch incorporation as green manure (130 kg N ha1 y1) (GMAN). Along the maize period (MP), reduced daily N2O emissions were detected in organic treated soils compared to CONV, mainly in the first stages of the cultivation, thanks to the slow release of available nitrogen from the organic substrates. Cumulative N2O fluxes (kg N2O-N ha1) in MP scored to 0.24, 0.14, 0.12 and 0.085 for CONV, COM1, COM2 and GMAN, respectively, with significantly lower emissions in GMAN respect to CONV. CO2 fluxes partially reflected the ranking observed for maize yields, with cumulated values (Mg CO2-C ha1) of 2.2, 1.5, 2.1, 2.1 for CONV, COM1, COM2 and GMAN, respectively, and significantly lower in COM1 respect to the other treatments. During the fallow period (FP), compared to CONV (0.77 Mg CO2-C ha1 and 0.25 kg N2O-N ha1), enhanced GHG fluxes were detected in COM treatments (about 0.90 Mg CO2-C ha1 and 0.37 kg N2O-N ha1, as averaged values from COM1 and COM2), likely driven by the slow prolonged mineralization of the added organic matter. GMAN showed comparable CO2 (0.82 Mg CO2-C ha1) and N2O emissions (0.30 kg N2O-N ha1), in consequence of restrained post-harvest residual N coupled with the counteracting effect of vetch uptake. Respect to the total yearly GHG emissions in CONV (about 194 kg CO2 eq ha1 y1), the overall results showed commensurate slightly higher GWP in COM treatments (þ11% as averaged value from COM1 and COM2). The yield-scaled global warming potential (GWP) resulted 60% higher and nearly doubled for COM2 and COM1 respectively, according to the lower COM yields, markedly dampening at halved compost dose. GMAN appeared the best performing organic treatment, with lower GWP (27%) and competitive yields respect to CONV. All treatments showed N2O emission factors consistently lower compared with the default IPCC 1% value

Biotechnological synthesis of succinic acid by actinobacillus succinogenes by exploitation of lignocellulosic biomass

Succinic acid is increasingly used in pharmaceutical industries, for the production of additives in food industries, in agriculture and in refinery processes as a precursor of many chemical compounds among which the most important is the succinate salt. It is also used as an ion chelator and surfactant, and for the biochemicals production. Currently, succinic acid is mainly produced through chemical petroleum-based processes, usually from n-butane using maleic anhydride. However, the use of petrochemical feedstocks raises serious environmental problems, due to the higher values of temperature and pressure required. The biotechnological production of succinic acid by microbial conversion of lignocellulosic biomass is attracting growing interest due to the environmental and economic advantages offered. This research is focused on the exploitation of Arundo donax (Giant reed) as a source of lignocellulosic biomass. Arundo donax is a perennial crop particularly suitable for energy production, as it offers high yields per hectare, even in partially fertile or polluted soils, not used for agriculture. Hydrolyzate of Arundo donax will be used as growth media for the Actinobacillus succinogenes 130Z, a bacterium typically found in the bovine rumen, that is recognized as one of the most promising for the biotechnological production of succinic acid, as it is able to produce higher concentrations of succinic acid. The experimental analysis is carried out to optimize the production of succinic acid taking into account the effect of the most critical parameters of the process (microbial biomass, pH, reducing sugars, volatile fatty acids, and succinic acid). Tests have shown that in 48h the sugars are completely biodegraded with a total production of bio-succinic acid of 5.9 g for 9.1 g of reducing sugars, an hourly production 0.12 g h-1 with a yield equal to 65%

Comparative assessment of autochthonous bacterial and fungal communities and microbial biomarkers of polluted agricultural soils of the Terra dei Fuochi

Organic and inorganic xenobiotic compounds can affect the potential ecological function of the soil, altering its biodiversity. Therefore, the response of microbial communities to environmental pollution is a critical issue in soil ecology. Here, a high-throughput sequencing approach was used to investigate the indigenous bacterial and fungal community structure as well as the impact of pollutants on their diversity and richness in contaminated and noncontaminated soils of a National Interest Priority Site of Campania Region (Italy) called “Terra dei Fuochi”. The microbial populations shifted in the polluted soils via their mechanism of adaptation to contamination, establishing a new balance among prokaryotic and eukaryotic populations. Statistical analyses showed that the indigenous microbial communities were most strongly affected by contamination rather than by site of origin. Overabundant taxa and Actinobacteria were identified as sensitive biomarkers for assessing soil pollution and could provide general information on the health of the environment. This study has important implications for microbial ecology in contaminated environments, increasing our knowledge of the capacity of natural ecosystems to develop microbiota adapted to polluted soil in sites with high agricultural potential and providing a possible approach for modeling pollution indicators for bioremediation purposes

Degradative actions of microbial xylanolytic activities on hemicelluloses from rhizome of Arundo donax.

Polysaccharidases from extremophiles are remarkable for specific action, resistance to different reaction conditions and other biotechnologically interesting features. In this article the action of crude extracts of thermophilic microorganisms (Thermotoga neapolitana, Geobacillus thermantarcticus and Thermoanaerobacterium thermostercoris) is studied using as substrate hemicellulose from one of the most interesting biomass crops, the giant reed (Arundo donax L.). This biomass can be cultivated without competition and a huge amount of rhizomes remains in the soil at the end of cropping cycle (10–15 years) representing a further source of useful molecules. Optimization of the procedure for preparation of the hemicellulose fraction from rhizomes of Arundo donax, is studied. Polysaccharidases from crude extracts of thermophilic microorganisms revealed to be suitable for total degradative action and/or production of small useful oligosaccharides from hemicelluloses from A. donax. Xylobiose and interesting tetra- and pentasaccharide are obtained by enzymatic action in different conditions. Convenient amount of raw material was processed per mg of crude enzymes. Raw hemicelluloses and pretreated material show antioxidant activity unlike isolated tetra- and pentasaccharide. The body of results suggest that rhizomes represent a useful raw material for the production of valuable industrial products, thus allowing to increase the economic efficiency of A. donax cultivation

Agronomic approaches for the remediation of contaminated soils

Contaminated soils can only be efficiently managed if proper procedures are adopted for evaluating the risks due to contamination as well as the actual volume of contaminated soil [...