Nitrogen source effects on soil nitrous oxide emissions from strip-till corn

Nitrogen (N) application to crops generally results in increased nitrous oxide (NO) emissions. Commercially available, enhanced-efficiency N fertilizers were evaluated for their potential to reduce NO emissions from a clay loam soil compared with conventionally used granular urea and urea-ammonium nitrate (UAN) fertilizers in an irrigated strip-till (ST) corn ( L.) production system. Enhanced-efficiency N fertilizers evaluated were a controlled-release, polymer-coated urea (ESN), stabilized urea, and UAN products containing nitrification and urease inhibitors (SuperU and UAN+AgrotainPlus), and UAN containing a slow-release N source (Nfusion). Each N source was surface-band applied (202 kg N ha) at corn emergence and watered into the soil the next day. A subsurface-band ESN treatment was included. Nitrous oxide fluxes were measured during two growing seasons using static, vented chambers and a gas chromatograph analyzer. All N sources had significantly lower growing season NO emissions than granular urea, with UAN+AgrotainPlus and UAN+Nfusion having lower emissions than UAN. Similar trends were observed when expressing NO emissions on a grain yield and N uptake basis. Loss of NO-N per kilogram of N applied was <0.8% for all N sources. Corn grain yields were not different among N sources but greater than treatments with no N applied. Selection of N fertilizer source can be a mitigation practice for reducing NO emissions in strip-till, irrigated corn in semiarid areas.     

The role of water in the information exchange between the components of an ecosystem

Living organisms and ecosystems have been shown to be sensitive to very weak signals originating very far away. The dynamics governing these phenomena is discussed in the framework of Quantum Field Theory. This phenomenon gives an indication on the dynamics responsible for the exchange of information in ecosystems. The peculiar role of coherent water is stressed. It is shown that energy is able to travel in a coherent medium in form of solitons, without any losses.     

The Contribution by the Study of the Algae Forms (Phytoplankton and Periphyton) as Integrators of Physicochemical and Microbiological Data in the Varenna Stream

Physico-chemical, microbiological, ichthyotoxicological conditions and microalgae of Varenna stream were studied in samples taken in 12 collecting stations. The data reported indicate a marked deterioration proceeding downstream e.g. an increase of bacterial population, concentration of suspended solids, COD and variations in the composition and abundance of phytoplankton and periphyton.     

Presence of Cd‐binding proteins in pre‐exposed and not pre‐exposed cadmium brine shrimp Artemia

The presence of metal binding proteins has been variously suggested as indicating involvement in uptake, storage, transport and elimination of toxic metals and in the routine metabolism of metals in mammals and a variety of marine invertebrates. This report describes results on the characterization of Cd‐BPs obtained from cadmium pre‐exposed and not pre‐exposed Anemia. The effect of pre‐exposure in the Cd‐binding protein induction in Artemia is discussed.     

Characterization of syngas produced from MSW gasification at commercial-scale ENERGOS Plants

Characterization of the syngas produced in the gasification process has been performed at commercial-scale Energy-from-Waste plants under various conditions of lambda value and syngas temperature. The lambda value from the gasification process is here defined as the ratio of the gasification air to the total stoichiometric air for complete combustion of the fuel input. Evaluation of the syngas calorific value has been performed by three different methods, i.e., estimation of the syngas calorific value from continuous in-line process measurements by mass and energy conservation equations, measurement of the syngas composition based on gas chromatography and calculation of the Gross Calorific Value from the measured composition, and direct continuous measurement of the calorific value using based on gas calorimeter.     

Use of selected autochthonous soil bacteria to enhanced degradation of hydrocarbons in soil

A mixed population of soil hydrocarbon degrading bacteria was used to accelerate the biodegradation of a petrochemical waste. An aromatic hydrocarbon storage tank bottom was mixed with soil (10% w/w). After a month 43% of the hydrocarbons were degraded in uninoculated and in fertilized soil, while 65% were degraded in inoculated soil. Nutrient supplemented vermiculite seems to be a good possibility to produce effective hydrocarbon degrading inoculants.     

Uncertainty assessment of the model RICEWQ in northern Italy

Model predictions are often seriously affected by uncertainties arising from many sources. Ignoring the uncertainty associated with model predictions may result in misleading interpretations when the model is used by a decision-maker for risk assessment. In this paper, an analysis of uncertainty was performed to estimate the uncertainty of model predictions and to screen out crucial variables using a Monte Carlo stochastic approach and a number of statistical methods, including ANOVA and stepwise multiple regression. The model studied was RICEWQ (Version 1.6.1), which was used to forecast pesticide fate in paddy fields. The results demonstrated that the paddy runoff concentration predicted by RICEWQ was in agreement with field measurements and the model can be applied to simulate pesticide fate at field scale. Model uncertainty was acceptable, runoff predictions conformed to a log-normal distribution with a short right tail, and predictions were reliable at field scale due to the narrow spread of uncertainty distribution. The main contribution of input variables to model uncertainty resulted from spatial (sediment-water partition coefficient and mixing depth to allow direct partitioning to bed) and management (time and rate of application) parameters, and weather conditions. Therefore, these crucial parameters should be carefully parameterized or precisely determined in each site-specific paddy field before the application of the model, since small errors of these parameters may induce large uncertainty of model outputs.     

The role of electromagnetic potentials in the evolutionary dynamics of ecosystems

It is discussed that the electromagnetic potential can cause the emergence of the coherent structures that in view of their coherence, openness and non-linearity, are able to self-organize and form various hierarchical levels of ecosystems. In the meantime the electromagnetic potential is also the physical agent acting as a messenger in these coherent structures. So it plays the task of reducing the number of independent microstates of a coherent system, becoming a candidate for implementing the concept of negentropy. Electromagnetic potential is shown to be essential for the self-organization and the time evolution of ecosystems, providing the mechanism for their non-locality, complexity and self-consistency (self-maintaining).     

Sorption kinetics of chlortetracyline and tylosin on sandy loam and heavy clay soils

Antibiotics may appear in the environment when manure, sewage sludge, and other organic amendments are added to soils. There is concern that the presence of antibiotics in soils may lead to the development of antibiotic-resistant bacteria which may spread to the rest of the environment. This paper aims at evaluating the sorption kinetics of two antibiotics frequently used in pig production. The results indicate that sorption of chlortetracycline (CTC) and tylosin (TYL) in sandy loam and clay occurs very fast. More than 95% of the CTC adsorption is completed within 10 min on both soils and of TYL within 3 h. These results suggest that 24-h soil and antibiotic solution mixtures is enough for sorption studies. Also, there is less likelihood that these antibiotics will leach through soil and appear in the ground water since their sorption on soils is very high unless they are carried by soil particles through preferential flow. There was also no effect of soil sterilization on sorption kinetics of these antibiotics thus suggesting that there is minimal probability of the antibiotics degrading by microorganisms during 24- to 48-h adsorption studies.     

Cytotoxic and genotoxic effects of metal(oid)s bioactivated in rocket leaves (Eruca vesicaria subsp. sativa Miller)

Rocket is an important source of essential elements. However, it may also accumulate toxic elements such as metal(oids). The objectives of the present work were (i) to study the uptake of arsenic, lead, cadmium and zinc in rocket grown in contaminated soils, (ii) to establish the genotoxic and cytotoxic activities of this vegetable material, and (iii) to study the modulator role of the glucosinolate and metal contents in the genotoxic/cytotoxic activities. Lead, cadmium and zinc leaf concentrations in our study were over the concentrations allowed by the statutory limit set for metal(oid) contents in vegetables. The accessions were non genotoxic at the different concentrations studied, although one of the accessions showed the highest mutation rates doubling those of negative control. The cytotoxicity assays with HL60 human leukaemia cells showed that the tumouricide activities of rocket leaves decreased with the increasing of metal(oid) concentrations and also with the decreasing of glucosinolate concentrations in their tissues. An interaction between metal(oid)s and glucosinolate degradation products contained in rocket leaves is suggested as the main modulator agents of the biological activity of the plants grown in metal-contaminated soils.