Effects of organic fertilizers on soil physicochemistry and on the yield and botanical composition of forage over 3 years

Organic wastes have been reported to reduce saturation of the exchange complex by Al in Al-rich acid soils. For 3 years, the main soil fertility properties were studied in plots sown with mixed pasture species. These plots were fertilized with cattle slurry, dairy sludge (DS), or granulated broiler litter (BL) in comparison with mineral fertilizer. Al saturation levels were low after the initial inorganic liming treatment (19.00-33.71%) but tended to rise under all treatments (21.09-61.37%) except BL (8.45-30.98%), which was also associated with the highest average soil pH and the highest average levels of exchangeable Ca2+, Mg2+, and K+. Treatment DS performed similarly to mineral fertilizer in most respects, but it led to greater available P levels. Under the dry conditions of the second and third years of the study, BL and DS treatments were associated with significantly greater forage yields than the other treatments. Under DS treatment, available P levels were too low to allow the maintenance of mixed pasture, clover being eliminated by the less P-dependent species.     

Dynamics of phosphorus and phytate-utilizing bacteria during aerobic degradation of dairy cattle dung

During organic wastes degradation, P is transformed which may affect its availability. In this study, the dynamics of P and the occurrence of phytate-utilizing bacteria (PUB) were evaluated during aerobic degradation of dairy cattle dung in laboratory-scale reactors for 105 d. The results showed an increase of water-soluble inorganic P (Pi) (from 570 to 1890 mg kg(-1)) and biomass P (from 390 to 870 mg kg(-1)) during the initial 40 d. After this period, water-soluble Pi remained constant (around 1500 mg kg(-1)) and biomass P decreased (around 220 mg kg(-1)) probably due to the decrease of easily available C in dung. Under the acidic conditions in the first 20 d there was an increase in concentration of Al (25 mg kg(-1)) and Fe (27 mg kg(-1)) ions. These ions were no longer detectable in the alkaline conditions occurring after 40 d. In the same period, the Ca concentration increased (from 1170 to 2370 mg kg(-1)) and chemical speciation revealed permanent association of Ca ions with Pi. Sequential P fractionation showed a decrease of organic P in NaHCO(3), NaOH and HCl fractions and an increase of residual P (25-52% with respect to total P). Analysis by (31)P NMR also showed a decrease (from 14% to 1.6%) of phytic acid content during final experimental period (60 and 105 d). The bacteriological analysis revealed various PUB involved in degradation of the dung. Two morphotypes, genetically characterized as Enterobacter and Rahnella, which were dominant under higher content of residual P, showed strong utilization of phytate in vitro.     

Quality considerations of European PM emission inventories

This paper reviews information on emission inventories of particulate matter (PM) in Europe. A large body of scientific literature is available to cover many different aspects. Studies focus on specific sources or source sectors (road transport as well as off-road machinery, domestic heating, industry, agriculture, and natural sources), among which especially road transport emissions are clearly best established. Emission inventories comprising all sources are available for specific European regions, often pointing out regional differences, but also for the entire continent. Still these inventories often are not able to satisfy the needs. Due to PM specific circumstances such as the large number of sources, very different release pathways and differences of the individual particles in terms of chemical composition or size, it is very difficult to appropriately handle measurement conditions to arrive at adequate emission factors, especially when emission points cannot be defined clearly. Information on fugitive emissions (caused by wind shear, material transfer processes or other mechanical forces from non-point sources) is sparse, except for road traffic emissions where recent data seems to converge. The problem of data gaps concerns activities in industry (quarries), agriculture, but also natural particles like sea salt and wind-blown dust. Comparing complete inventories to independent efforts in assessing emissions, e.g. atmospheric measurements combined with source apportionment, allows to better understand and quantify the reliability of inventory data. Methodological improvements and harmonization currently under way in Europe will focus efforts and allow for more reliable PM inventories in the near future.     

Air pollution impacts of speed limitation measures in large cities: The need for improving traffic data in a metropolitan area

Assessing the effects of air quality management strategies in urban areas is a major concern worldwide because of the large impacts on health caused by the exposure to air pollution. In this sense, this work analyses the changes in urban air quality due to the introduction of a maximum speed limit to 80 km h^?1 on motorways in a large city by using a novel methodology combining traffic assimilation data and modelling systems implemented in a supercomputing facility. Albeit the methodology has been non-specifically developed and can be extrapolated to any large city or megacity, the case study of Barcelona is presented here. Hourly simulations take into account the entire year 2008 (when the 80 km h^?1 limit has been introduced) vs. the traffic conditions for the year 2007. The data has been assimilated in an emission model, which considers hourly variable speeds and hourly traffic intensity in the affected area, taken from long-term measurement campaigns for the aforementioned years; it also permits to take into account the traffic congestion effect. Overall, the emissions are reduced up to 4%; however the local effects of this reduction achieve an important impact for the adjacent area to the roadways, reaching 11%. In this sense, the speed limitation effects assessed represent enhancements in air quality levels (5–7%) of primary pollutants over the area, directly improving the welfare of 1.35 million inhabitants (over 41% of the population of the Metropolitan Area) and affecting 3.29 million dwellers who are potentially benefited from this strategy for air quality management (reducing 0.6% the mortality rates in the area).     

Organochlorine pesticide distribution in an organic production system for cow's milk in Chiapas,Mexico

The objective of this study was to evaluate the presence of organochlorine pesticides in samples of forage, soil, water, and milk in four units of an organic production system for cow´s milk (samples of forage, milk, soil, and water) in Tecpatan, Chiapas, Mexico. The organochlorine pesticides were extracted from forage, soil and water based on the USEPA (2005) guideline and from milk based on the IDF 1991 guideline. The pesticides were identified and quantified by gas chromatography with electron capture detector (CG-ECD). In general, the highest average concentration of total pesticides was found in the samples of milk and forage (311 ± 328 and 116.5 ±77 ng g^?1 respectively). Although, the production systems analyzed are organic, organochlorine pesticides were detected in all environmental samples (forage, soil, water, and organic milk). Although no values surpassed the defined limits of Mexican and International regulation it is advisable that a monitoring program of contaminants in these production systems is continued.     

Biological control of AFB1-producing Aspergillus section Flavi strains isolated from brewer's grains,alternative feed intended for swine production in Argentina

The aim of the present study was to investigate the inhibitory activity of lactic acid bacteria (LAB) isolated from brewer's grains on Aspergillus section Flavi growth and aflatoxin B₁ production. The Aspergillus strains tested were inhibited by all the LAB strains assayed. The isolates Lactobacillus brevis B20, P. pentosaceus B86, Lactococcus lactis subsp. lactis B87, L. brevis B131, and Lactobacillus sp. B144 completely suppressed the fungal growth and reduced aflatoxin B₁ production. In conclusion, LAB isolated from brewer's grains show a high inhibitory activity on fungal growth and aflatoxin biosynthesis by Aspergillus flavus and Aspergillus parasiticus. Further studies must be conducted to evaluate the success of in vitro assays under food environment conditions and to elucidate the antifungal mechanism of these strains.     

Improving bioavailability of phosphorous from cattle dung by using phosphatase immobilized on natural clay and nanoclay

The high P retention of acidic Andisols makes necessary to increase our technological approaches in pasture management in the animal system production. Here, we evaluated the clay- or nanoclay-acid phosphatase complexes for improving phosphorus mineralization from degraded cattle dung. We implemented an immobilization mechanism of acid phosphatase (AP) using natural clays (allophanic and montmorillonite) and nanoclays as support materials. Also, we evaluated the mineralization of organic P containing in decomposed cattle dung with clay- and nanoclay-AP complexes by incubation studies. Clays and nanoclays were characterized by microscopy techniques as atomic force and confocal-laser scanning microscopy. We found that these support materials stabilized AP by encapsulation. Our results showed that immobilization on allophanic or montmorillonite materials improved both the specific activity (4-48%) and the V_max (28-38%) of AP. Moreover, the enzyme had a better performance when immobilized on clay and nanoclay from Andisol than on montmorillonite materials. Phosphorous mineralization of cattle dung was regulated by water-soluble P present in the dung and P re-adsorption on allophanic materials. However, we were able to detect a potential capacity of AP immobilized on allophanic nanoclays as the best alternative for P mineralization. Further research with initially low water-soluble P containing organic materials is required to quantify the P mineralization potential and bioavailability of P from dung.     

Analytical improvements of hybrid LC-MS/MS techniques for the efficient evaluation of emerging contaminants in river waters: a case study of the Henares River (Madrid, Spain)

Purpose  

Instrumental capabilities and software tools of modern hybrid mass spectrometry (MS) instruments such as high-resolution mass spectrometry (HRMS), quadrupole time-of-flight (QTOF), and quadrupole linear ion trap (QLIT) were experimentally investigated for the study of emerging contaminants in Henares River water samples.     

Phytoremediation of phenol using Vicia sativa L. plants and its antioxidative response

Common vetch (Vicia sativa L.) is a legume species with an extensive agricultural use. However, the phytoremediation potentiality of this species has not been sufficiently explored because little is known about its resistance to inorganic and organic pollutants. In the present work, phenol tolerance of common vetch was assayed at different stages of growth. Germination index and germination rate decreased only at high phenol concentrations (250 and 500 mg L(-1)), whereas 30-day-old plants were able to tolerate this pollutant, with high removal efficiencies. The activities of antioxidative enzymes, such as peroxidase (POD) and ascorbate peroxidase, increased significantly with the highest phenol concentration, whereas superoxide dismutase activity, malondialdehyde, and H(2)O(2) levels remained unaltered. Besides, an increase in two basic isoforms of POD was observed in plants treated with phenol. The results suggested that common vetch has an efficient protection mechanism against phenol-induced oxidative damage. Moreover, it could tolerate and remove high phenol concentrations, avoiding serious phytotoxic effects. Thus, V. sativa could be considered an interesting tool in the field of phytoremediation.