Siting restrictions and proximity of Concentrated Animal Feeding Operations to surface water

Proximity and connections to surface waters may play significant roles in determining impacts of manure spills. As occurred in many U.S. states, Minnesota adopted in 2000 more stringent regulations on Concentrated Animal Feeding Operations (CAFOs) including restrictions on siting new facilities near surface waters. The objectives of this study were to determine whether CAFO proximity to surface waters decreased following the siting restrictions and to evaluate implications of siting restrictions. Permit dates, locations, and distances to nearest surface water bodies for 111 west central Minnesota CAFOs were determined based on satellite imagery, historical records, and correspondence with regulatory officials. Average distance between surface waters and facilities permitted after 2000 was greater than for facilities permitted before 2000. The increase in average distance between CAFOs and public surface waters was significant for open water (1790 m, p = 0.03), but not for streams (280 m, p = 0.47). Decreased CAFO proximity to surface waters should benefit water quality, but after 2000 facilities continued to be permitted close to hydraulic connections not covered by the siting restriction. Comprehensive manure spill tracking and long term targeted water quality monitoring are needed to evaluate effectiveness of siting restrictions and other strategies for protecting surface waters from manure spills.     

Minimizing air pollution exposure: A practical policy to protect vulnerable older adults from death and disability

Air pollution causes an estimated 200,000 deaths per year in the United States alone. Older adults are at greater risk of mortality caused by air pollution. Here we quantify the number of older adult facilities in Los Angeles County who are exposed to high levels of traffic derived air pollution, and propose policy solutions to reduce pollution exposure to this vulnerable subgroup. Distances between 20,362 intersections and 858 elder care facilities were estimated, and roads or highways within 500 of facilities were used to estimate traffic volume exposure. Of the 858 facilities, 54 were located near at least one major roadway, defined as a traffic volume over 100,000 cars per day. These 54 facilities house approximately 6000 older adults. Following standards established for schools, we recommend legislation mandating the placement of new elder care facilities a minimum of 500 ft from major roadways in order to reduce unnecessary mortality risk from pollution exposure.     

Process modification in the scouring process of textile industry

The effects of scouring parameters on the scouring efficiency, including the weight ratio of de-sizing agent and fabric (5–80 g/g fabric), temperature of de-sizing agent tank (60–90 °C) and dipping time (2–8 s), were investigated. The results demonstrated that weight loss of sizing agent was significantly observed only in the de-sizing agent tank particularly in the first de-sizing tank and was found to a small extent in water tank. The optimum condition in the scouring machine was found at a de-sizing agent to fabric ratio of 20 g/g fabric, with a temperature of the first de-sizing agent tank of 80 °C, a temperature of the second de-sizing agent tank of 90 °C, and dipping time of fabric of 7 s. According to these conditions, more than 89% of the sizing agent was eliminated and only 3.52 mg/g fabric of sizing agent remained in the scoured fabric which was in an acceptable range for feeding to the down stream process known as dyeing process. Application of our results to actual textile plant has shown that there is a cost reduction due to improved utilization of rinse water, chemicals and energy in the process and consequent decreases in the generation of wastewater. Furthermore, the production capacity was increased from 30 m/min to 34.4 m/min.     

Fostering pollution prevention in small businesses: the Enviroclub initiative

The Enviroclub initiative was developed by three federal government agencies (Canada Economic Development for Quebec Regions, Environment Canada and the National Research Council Canada) to assist small and medium sized enterprises (SMEs) in improving their profitability and competitiveness through enhanced environmental performance. An Enviroclub consists of a group of 10–15 SMEs, each of which carries out one profitable pollution prevention project. To support this practical experience, business participants attend 4 days of workshops on various themes related to environmental performance, spread out over a period of about 6 months. Enviroclubs have been undertaken in several regions of Quebec, and are delivered by not-for-profit organisations, mainly Enviro-Access and the Centre québécois de développement durable. Projects implemented in seven Enviroclubs brought annual savings of CAD$5.1 million and multiple environmental benefits including annual reductions in resource use, such as water (536,000 m³), petroleum products (225,000 litres), wood (11,300 m³) and emissions, such as greenhouse gases (17,100 tonnes equivalent CO₂), hazardous wastes (708 tonnes) and toxic substances (53 tonnes).     

Comparing intensive,extensified and organic grassland farming in southern Germany by process life cycle assessment

To reduce the environmental burden of agriculture, suitable methods to comprehend and assess the impact on natural resources are needed. One of the methods considered is the life cycle assessment (LCA) method, which was used to assess the environmental impacts of 18 grassland farms in three different farming intensities — intensive, extensified, and organic — in the Allgäu region in southern Germany. Extensified and organic compared with intensive farms could reduce negative effects in the abiotic impact categories of energy use, global warming potential (GWP) and ground water mainly by renouncing mineral nitrogen fertilizer. Energy consumption of intensive farms was 19.1 GJ ha⁻¹ and 2.7 GJ t⁻¹ milk, of extensified and organic farms 8.7 and 5.9 GJ ha⁻¹ along with 1.3 and 1.2 GJ t⁻¹ milk, respectively. Global warming potential was 9.4, 7.0 and 6.3 CO₂-equivalents ha⁻¹ and 1.3, 1.0 and 1.3 CO₂-equivalents t⁻¹ milk for the intensive, extensified and organic farms, respectively. Acidification calculated in SO₂-equivalents was high, but the extensified (119 kg SO₂ ha⁻¹) and the organic farms (107 kg SO₂ ha⁻¹) emit a lower amount compared with the intensive farms (136 kg SO₂ ha⁻¹). Eutrophication potential computed in PO₄-equivalents was higher for intensive (54.2 kg PO₄ ha⁻¹) compared with extensified (31.2 kg PO₄ ha⁻¹) and organic farms (13.5 kg PO₄ ha⁻¹). Farmgate balances for N (80.1, 31.4 and 31.1 kg ha⁻¹) and P (5.3, 4.5 and −2.3 kg ha⁻¹) for intensive, extensified and organic farms, respectively, indicate the different impacts on ground and surface water quality. Analysing the impact categories biodiversity, landscape image and animal husbandry, organic farms had clear advantages in the indicators number of grassland species, grazing cattle, layout of farmstead and herd management, but indices in these categories showed a wide range and are partly independent of the farming system.     

Ammonia and nitrous oxide emissions following land application of high and low nitrogen pig manures to winter wheat at three growth stages

Nitrous oxide (N₂O) and ammonia (NH₃) emissions from surface applied high (HN) and low (LN) nitrogen pig manures were measured under field conditions. Manures were band-spread to a winter wheat crop at three growth stages—mid-tillering, stem elongation and flag leaf emergence. The N₂O flux rates were measured using the static chamber technique while NH₃ volatilisation was assessed using a micrometeorological mass balance technique with passive flux samplers. The N₂O emissions were episodic in nature with flux rates observed ranging from 2.8 to 31.5 g N₂O–N ha^?1 day^?1 (P < 0.001). Higher N₂O emissions generally occurred after rainfall events. Highest N₂O losses were observed from the HN treatment with LN manure use decreasing emissions by 18% (P < 0.03). The NH₃ volatilisation rates were highest within 1 h of manure application with 95% of emissions occurring within 24 h (P < 0.001). Cumulative N loss was highest at mid-tillering as low crop canopy cover and increased wind-speeds enhanced NH₃ loss (P < 0.001). Highest emissions were measured from the HN manure (P < 0.03). Total ammoniacal N loss ranged from 6 to 11%. Crop N uptake and grain yield were unaffected by application timing or manure type. Therefore, the use of LN manures decreased gaseous emissions of N₂O and NH₃ without any adverse effects on crop performance.     

Lodging in rice can be alleviated by atmospheric CO2 enrichment

The projected increase of atmospheric CO₂ concentration [CO₂] is expected to increase yield of agricultural C₃ crops, but little is known about effects of [CO₂] on lodging that can reduce yield. This study examined the interaction between [CO₂] and nitrogen (N) fertilization on the lodging of rice (Oryza sativa L.) using free-air CO₂ enrichment (FACE) systems installed in paddy fields at Shizukuishi, Iwate, Japan (39°38′N, 140°57′E). Rice plants were grown under two levels of [CO₂] (ambient = 365 μmol mol⁻¹; elevated [CO₂] = 548 μmol mol⁻¹) and three N fertilization regimes: a single initial basal application of controlled-release urea (8 g N m⁻², CRN), split fertilization with a standard amount of ammonium sulfate (9 g N m⁻², MN), and ample N (15 g N m⁻², HN). Lodging score (six ranks at 18° intervals, with larger scores indicating greater bending), yield, and yield components were measured at maturity. The lodging score was significantly higher under HN than under CRN and MN, but lodging was alleviated by elevated [CO₂] under HN. This alleviation was associated with the shortened and thickened lower internodes, but was not associated with a change in the plant's mass moment around the culm base. A positively significant correlation between lodging score and ripening percentage indicated that ripening percentage decreased by 4.5% per one-unit increase in lodging score. These findings will be useful to develop functional algorithm that can be incorporated into mechanistic crop models to predict rice production more accurately in a changing climate and with different cultural practices.     

Exceedance of modern ‘background’ fine-grained sediment delivery to rivers due to current agricultural land use and uptake of water pollution mitigation options across England and Wales

Excessive loss of fine-grained sediment to rivers is widely recognised as a global environmental problem. To address this issue, policy teams and catchment managers require an estimate of the ‘gap’ requiring remediation, as represented by the excess above ‘background’ losses. Accordingly, recent work has estimated the exceedance of modern ‘background’ sediment delivery to rivers at national scale across England and Wales due to (i) current agricultural land cover, cropping and stocking, and (ii) current land use corrected for the uptake of on-farm mitigation measures. This sectoral focus recognises that, nationally, agriculture has been identified as the principal source of fine sediment loss to the aquatic environment. Two estimates of modern ‘background’ sediment loss, based on paleolimnological evidence, were used in the analysis; the target modern ‘background’ (TMBSDR) and maximum modern ‘background’ (MMBSDR) sediment delivery to rivers. For individual (n = 4485) non-coastal water bodies, the sediment ‘gap’ in excess of TMBSDR and MMBSDR, due to current land cover, cropping and stocking, was estimated to range up to 1368 kg ha⁻¹ yr⁻¹ (median 61 kg ha⁻¹ yr⁻¹) and 1321 kg ha⁻¹ yr⁻¹ (median 19 kg ha⁻¹ yr⁻¹), respectively. The respective ranges in conjunction with current land cover, cropping and stocking but corrected for the potential impact of on-farm sediment mitigation measures were up to 1315 kg ha⁻¹ yr⁻¹ (median 50 kg ha⁻¹ yr⁻¹) and 1269 kg ha⁻¹ yr⁻¹ (median 8 kg ha⁻¹ yr⁻¹). Multiplication of the estimates of excess sediment loss corrected for current measure uptake, above TMBSDR and MMBSDR, with estimated maximum unit damage costs for the detrimental impacts of sediment pollution on ecosystem goods and services, suggested respective water body ranges up to 495 £ ha⁻¹ yr⁻¹ and 478 £ ha⁻¹ yr⁻¹. Nationally, the total loss of sediment in excess of TMBSDR was estimated at 1,389,818 t yr⁻¹ equating to maximum environmental damage costs of £523 M yr⁻¹, due to current structural land use, compared to 1,225,440 t yr⁻¹ equating to maximum damage costs of £462 M yr⁻¹ due the uptake of on-farm sediment control measures. The corresponding total loss of sediment in excess of MMBSDR was estimated at 1,038,764 t yr⁻¹ equating to maximum damage costs of £462 M yr⁻¹, compared with 890,146 t yr⁻¹ and £335 M yr⁻¹ correcting excess agricultural sediment loss for current implementation of abatement measures supported by policy instruments. This work suggests that the current uptake of sediment control measures on farms across England and Wales is delivering limited benefits in terms of reducing loadings to rivers and associated environmental damage costs.     

Soil-profile organic carbon and total nitrogen during 12 years of pasture management in the Southern Piedmont USA

Soil organic C (SOC) and total soil N (TSN) sequestration estimates are needed to improve our understanding of management influences on soil fertility and terrestrial C cycling related to greenhouse gas emission. We evaluated the factorial combination of nutrient source (inorganic, mixed inorganic and organic, and organic as broiler litter) and forage utilization (unharvested, low and high cattle grazing pressure, and hayed monthly) on soil-profile distribution (0–150 cm) of SOC and TSN during 12 years of pasture management on a Typic Kanhapludult (Acrisol) in Georgia, USA. Nutrient source rarely affected SOC and TSN in the soil profile, despite addition of 73.6 Mg ha^?1 (dry weight) of broiler litter during 12 years of treatment. At the end of 12 years, contents of SOC and TSN at a depth of 0–90 cm under haying were only 82 ± 5% (mean ± S.D. among treatments) of those under grazed management. Within grazed pastures, contents of SOC and TSN at a depth of 0–90 cm were greatest within 5 m of shade and water sources and only 83 ± 7% of maximum at a distance of 30 m and 92 ± 14% of maximum at a distance of 80 m, suggesting a zone of enrichment within pastures due to animal behavior. During 12 years, the annual rate of change in SOC (0–90 cm) followed the order: low grazing pressure (1.17 Mg C ha^?1 year^?1) > unharvested (0.64 Mg C ha^?1 year^?1) = high grazing pressure (0.51 Mg C ha^?1 year^?1) > hayed (?0.22 Mg C ha^?1 year^?1). This study demonstrated that surface accumulation of SOC and TSN occurred, but that increased variability and loss of SOC with depth reduced the significance of surface effects.     

Long-term impact of a gliricidia-maize intercropping system on carbon sequestration in southern Malawi

Tree/crop systems under agroforestry practice are capable of sequestering carbon (C) in the standing biomass and soil. Although studies have been conducted to understand soil organic C increases in some agroforestry technologies, little is known about C sequestered in simultaneous tree/crop intercropping systems. The main objective of this study was to determine the effect of agroforestry practice on C sequestration and CO₂-C efflux in a gliricidia-maize intercropping system. The experiment was conducted at an experimental site located at the Makoka Agricultural Research Station, in Malawi. The studies involved two field plots, 7-year (MZ21) and 10-year (MZ12), two production systems (sole-maize and gliricidia-maize simultaneous intercropping systems). A 7-year-old grass fallow (Grass-F) was also included. Gliricidia prunings were incorporated at each time of tree pruning in the gliricidia-maize. The amount of organic C recycled varied from 0.8 to 4.8 Mg C ha⁻¹ in gliricidia-maize and from 0.4 to 1.0 Mg C ha⁻¹ in sole-maize. In sole-maize, net decreases of soil carbon of 6 Mg C ha⁻¹ at MZ12 and 7 Mg C ha⁻¹ at MZ21 in the topsoil (0–20 cm) relative to the initial soil C were observed. After 10 years of continuous application of tree prunings C was sequestered in the topsoil (0–20 cm) in gliricidia-maize was 1.6 times more than in sole-maize. A total of 123–149 Mg C ha⁻¹ were sequestered in the soil (0–200 cm depth), through root turnover and pruning application in the gliricidia-maize system. Carbon dioxide evolution varied from 10 to 28 kg ha⁻¹ day⁻¹ in sole-maize and 23 to 83 kg ha⁻¹ day⁻¹ in gliricidia-maize. We concluded that gliricidia-maize intercropping system could sequester more C in the soil than sole-maize.     

On wear resistance of tool steel

Maintaining a reasonably low cutting tool wear when producing forming tools is a general challenge in the development of new forming tool materials. The tool life of a hot forming tool steel (H13) has been significantly improved by reducing its Si-content from 1.0 to 0.06 wt.%. However, this modified H13 (MH13) also displays a reduced cutting tool life due to higher cutting forces and a stronger tendency to form built up layers (BUE) on the cutting edge. This paper explains why.Gleeble tests of MH13 revealed a significantly higher flow stress in the 820–900 °C temperature interval in MH13 compared to H13. Thermo-Calc simulations showed that when reducing the Si-content from 1.0 to 0.06 wt.% the initial temperature for ferrite-to-austenite transformation (A1) was reduced from 900 °C to 820 °C. Knowing that austenite has totally different mechanical and thermal properties than ferrite, the difference in A1 between the two steels explains the higher cutting forces and higher tendency for BUE-formation. The conclusion is that the difference in machinability between H13 and MH13 is primarily related to their difference in A1.An attempt was also made to find a new tool material composition that can combine the wear resistance of MH13 and the good machinability of H13. Thermo-Calc simulations were performed with slightly modified alloying content without changing its properties as a good forming tool material, with the aim to increase A1. For instance, reducing the Mn content from 0.5 to 0.05 wt.% proved to increase A1 from 820 to 850 °C.     

Hermetic joining of 316L stainless steel using a patterned nickel nanoparticle interlayer

This paper evaluates the use of a nickel nanoparticle (NiNP) interlayer for making hermetic joints in 316L stainless steel substrates via diffusion brazing. Different NiNP inks were prepared using commercial nanopowder (～9 nm) and in-house synthesized nanoparticles. Syringe pump deposition of ～9 nm NiNP ink and diffusion brazing at 900 °C for 30 min under 2 MPa resulted in a hermetic joint up to the tested pressure of 70 psi. In-house synthesis of NiNPs was carried out in ethylene glycol by the reduction of NiCl₂·6H₂O in the presence of hydrazine (N₂H₄) as a reducing agent. X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM) results confirm the presence of pure fcc-Ni with an average particle size of 5.4 ± 0.9 nm. An as-synthesized suspension of NiNPs was patterned onto 316L stainless steel laminae via automated dispensing to a thickness of ～3 μm and bonded at 800 °C for 30 min at a pressure of 2 MPa. The diffusion-brazed test article was also found to be hermetic up to 70 psi. An examination of the bond line using scanning electron microscopy (SEM) showed good uniformity and continuity.     

Evaluation of two soil carbon models using two Kenyan long term experimental datasets

RothC and Century are two of the most widely used soil organic matter (SOM) models. However there are few examples of specific parameterisation of these models for environmental conditions in East Africa. The aim of this study was therefore, to evaluate the ability of RothC and the Century to estimate changes in soil organic carbon (SOC) resulting from varying land use/management practices for the climate and soil conditions found in Kenya. The study used climate, soils and crop data from a long term experiment (1976–2001) carried out at The Kabete site at The Kenya National Agricultural Research Laboratories (NARL, located in a semi-humid region) and data from a 13 year experiment carried out in Machang’a (Embu District, located in a semi-arid region). The NARL experiment included various fertiliser (0, 60 and 120 kg of N and P₂O₅ ha⁻¹), farmyard manure (FYM—5 and 10 t ha⁻¹) and plant residue treatments, in a variety of combinations. The Machang’a experiment involved a fertiliser (51 kg N ha⁻¹) and a FYM (0, 5 and 10 t ha⁻¹) treatment with both monocropping and intercropping. At Kabete both models showed a fair to good fit to measured data, although Century simulations for treatments with high levels of FYM were better than those without. At the Machang’a site with monocrops, both models showed a fair to good fit to measured data for all treatments. However, the fit of both models (especially RothC) to measured data for intercropping treatments at Machang’a was much poorer. Further model development for intercrop systems is recommended. Both models can be useful tools in soil C predictions, provided time series of measured soil C and crop production data are available for validating model performance against local or regional agricultural crops.     

Response of “Alamo” switchgrass tissue chemistry and biomass to nitrogen fertilization in West Tennessee,USA

Switchgrass (Panicum virgatum) is a perennial, warm-season grass that has been identified as a potential biofuel feedstock over a large part of North America. We examined above- and belowground responses to nitrogen fertilization in “Alamo” switchgrass grown in West Tennessee, USA. The fertilizer study included a spring and fall sampling of 5-year old switchgrass grown under annual applications of 0, 67, and 202 kg N ha^?1 (as ammonium nitrate). Fertilization changed switchgrass biomass allocation as indicated by root:shoot ratios. End-of-growing season root:shoot ratios (mean ± SE) declined significantly (P ≤ 0.05) at the highest fertilizer nitrogen treatment (2.16 ± 0.08, 2.02 ± 0.18, and 0.88 ± 0.14, respectively, at 0, 67, and 202 kg N ha^?1). Fertilization also significantly increased above- and belowground nitrogen concentrations and decreased plant C:N ratios. Data are presented for coarse live roots, fine live roots, coarse dead roots, fine dead roots, and rhizomes. At the end of the growing season, there was more carbon and nitrogen stored in belowground biomass than aboveground biomass. Fertilization impacted switchgrass tissue chemistry and biomass allocation in ways that potentially impact soil carbon cycle processes and soil carbon storage.     

Soil C storage as affected by tillage and straw management: An assessment using field measurements and model predictions

Soil tillage and straw management are both known to affect soil organic matter dynamics. However, it is still unclear whether, or how, these two practices interact to affect soil C storage, and data from long term studies are scarce. Soil C models may help to overcome some of these problems. Here we compare direct measurements of soil C contents from a 9 year old tillage experiment to predictions made by RothC and a cohort model. Soil samples were collected from plots in an Irish winter wheat field that were exposed to either conventional (CT) or shallow non-inversion tillage (RT). Crop residue was removed from half of the RT and CT plots after harvest, allowing us to test for interactive effects between tillage practices and straw management. Within the 0–30 cm layer, soil C contents were significantly increased both by straw retention and by RT. Tillage and straw management did not interact to determine the total amount of soil C in this layer. The highest average soil C contents (68.9 ± 2.8 Mg C ha^?1) were found for the combination of RT with straw incorporation, whereas the lowest average soil C contents (57.3 ± 2.3 Mg C ha^?1) were found for CT with straw removal. We found no significant treatment effects on soil C contents at lower depths. Both models suggest that at our site, RT stimulates soil C storage largely by decreasing the decomposition of old soil C. Extrapolating our findings to the rest of Ireland, we estimate that RT will lead to C mitigation ranging from 0.18 to 1.0 Mg C ha^?1 y^?1 relative to CT, with the mitigation rate depending on the initial SOC level. However, on-farm assessments are still needed to determine whether RT management practices can be adopted under Irish conditions without detrimental effects on crop yield.     

Use of life cycle assessment methodology for determining phytoremediation potentials of maize-based cropping systems in fields with nitrogen fertilizer over-dose

Using the life cycle assessment (LCA) method, we analyzed the effects of different cropping systems (sole maize (CK), maize + soybean (CST) and maize + groundnut (CGT)) on the environment. The comprehensive index of environmental impacts varied in the order, sole maize > maize + groundnut > maize + soybean, with corresponding intercropping values of 0.1295, 0.1229 and 0.0945, respectively. The results showed that intercropping maize with suitable plants (e.g., groundnut and soybean) could reduce the adverse effects of over-application of nitrogen fertilizer on the environment. The study further showed that the LCA method may be a convenient and effective approach for analyzing the environmental impact of fertilizer management in agricultural fields.     

Effects of different diets on utilization of nitrogen from cattle slurry applied to grassland on a sandy soil in The Netherlands

Dietary adjustments have been suggested as a means to reduce N losses from dairy systems. Differences in fertilizing value of dairy slurry as a result of dietary adjustments were evaluated in a 1-year grassland experiment and by long-term modelling. Slurry composition of non-lactating dairy cows was manipulated by feeding diets with extreme high and low levels of dietary protein and energy. C:N_total ratio of the produced slurries ranged from 5.1 to 11.4. To evaluate their short-term fertilizer N value, the experimental slurries (n = 8) and slurries from commercial farms with variable composition (n = 4), were slit-injected in two grassland fields on the same sandy soil series in the north of The Netherlands (53°10′N, 6°04′E), with differences in sward age and ground water level. The recently established grassland field (NEW) was characterized by lower soil OM, N and moisture contents, less herbs and more modern grass varieties compared to the older grassland field (OLD). Slurry was applied in spring (100 kg N ha⁻¹) and after the first cut (80 kg N ha⁻¹) while in total four cuts were harvested. Artificial fertilizer N treatments were included in the experiment to calculate the mineral fertilizer equivalent (MFE) of slurry N. The OLD field showed a higher total N uptake whereas DM yields were similar for the two fields. Average MFE of the slurries on the OLD field (47%) was lower than on the NEW field (56%), probably as a result of denitrification of slurry N during wet conditions in spring. Slurries from high crude protein diets showed a significantly higher MFE (P < 0.05) compared to low crude protein diets. No significant differences in MFE were observed between slurries from high and low energy diets. On both fields, MFE appeared to be positively related to the ammonium content (P < 0.001) and negatively to the C:N_total ratio of the slurry DM (P = 0.001). Simulation of the effect of long-term annual application of 180 kg N ha⁻¹ with highest and lowest C:N_total ratio suggested that both slurries would lead to an increase in annual soil N mineralization. Both soil N mineralization and SOC appeared to be substantially higher in equilibrium state for the slurry with the highest C:N_total ratio. It is concluded that in a situation with slit-injection, the reduced first-year N availability of slurry with a high C:N_total ratio as observed in the grassland experiment will only be compensated for by soil N mineralization on the very long term.     

On the relationship between PM2.5 concentrations and regional-scale primary PM emissions for the United Kingdom: an issue of subsidiarity

A site-specific particulate matter PM source apportionment model has been used to estimate the contributions from local primary PM emissions, regional primary PM emissions and the regional background to PM_2.5 concentrations at 102 monitoring site locations and to the centres of 1 km × 1 km grid squares across the United Kingdom. The local primary PM contributions have then been compared with Europe-wide urban PM_2.5 increments estimated at 50 km × 50 km in European-scale integrated assessment models. It is concluded that Europe-wide PM increments used in policy analyses grossly underestimate urban PM concentrations obtained from the site-specific PM source apportionment model for the United Kingdom. Europe-wide urban PM_2.5 increments estimated at 5 km × 5 km scale are significantly improved, particularly for London, but underestimate those for smaller towns and cities by factors of 2–3. These underestimations have important air quality policy ramifications. Although environmental policies may well be best formulated at the European scale, the underpinning air quality modelling may be best carried out at the local scale.     

Using supercritical carbon dioxide as solvent to replace water in polyethylene terephthalate (PET) fabric dyeing procedures

Dyeing fabrics in supercritical carbon dioxide (SCD) instead of water can save energy, reduce water use and prevent pollution. The special pilot plant was designed to test dyeing procedures in supercritical carbon dioxide and the analyses of the results indicate major benefits as compared to water based procedures. The dyeing of polyethylene terephthalate (PET) fabric in supercritical carbon dioxide using special pilot plant was investigated. Disperse dye, C.I. (color index) Disperse Blue 79, was used in this study. After dyeing, rinsing in supercritical carbon dioxide, which removes the excess dyes, was also discussed. At the same dyeing conditions, K/S (color yield) of dyed fabric significantly increased with increasing the dye concentration from 1% o.w.f. (on weight of fabric) to 5% o.w.f. Dyeing temperature and pressure had a strong influence on the color yield. When the temperature rose above 110 °C, the increase in color yield was obvious. At 20 MPa, 120–130 °C, dyeing reached equilibrium after 60 min. The excess dye of the dyed PET fabric was small. The suitable condition in supercritical carbon dioxide for removal of excess dye from the dyed fabric was 70 °C, 20 MPa. The PET fabric dyed in supercritical carbon dioxide had good fastness and physical properties.     

Performance and water-use efficiency (single-leaf vs. whole-canopy) of well-watered and half-stressed split-root Lambrusco grapevines grown in Po Valley (Italy)

‘Lambrusco a foglia frastagliata’ grapevines (Vitis vinifera L.) were grown outdoors at Piacenza (44°55′N, 9°44′E, Po Valley, Italy) with the root system split between two 30-L pots and subjected from pre-veraison (17 July) to harvest (5 September) to soil drying of half of the root system (HS) induced by withholding water from one of the two pots as compared to well-watered (WW) vines (both pots daily recharged at field capacity). Volumetric soil-water content, pre-dawn and mid-morning leaf water potential, single-leaf gas-exchange as assimilation rate, stomatal conductance and transpiration were monitored throughout the trial. Whole-canopy gas-exchange as net CO₂ exchange rate (NCER) and transpiration were tracked from 31 August to 7 September on three vines per treatment on a 24-h basis using an enclosure method. Primary leaf carbon isotope (δ¹³C) composition, yield components and must composition were determined at harvest.Withdrawing water from one pot triggered a water stress response showing higher stomatal sensitivity to changes in air vapour pressure deficit, relatively low assimilation rates, high intrinsic and extrinsic water-use efficiency (WUE) and earlier cessation of shoot growth. Yet, mid-morning leaf water potential was consistently lower in HS treatment over stress as compared to WW, indicating an anisohydric adjustment. Canopy NCER given on a leaf-area basis showed mean daily rates ranging from 3.9 to 4.9 μmol m² s^?1 in WW canopies against 2.6–3.0 μmol m^?2 s^?1 in HS. Conversely, canopy transpiration rates varied from 0.915 to 1.157 mmol m^?2 s^?1 for WW to 0.630–0.714 mmol m² s^?1 in HS. Increased leaf-based intrinsic and extrinsic WUE in HS did not match the canopy response, which to some extent resulted in an opposite outcome, i.e. higher canopy WUE in well-watered vines especially in the morning hours. Likewise, δ¹³C did not differ between treatments. This suggests caution when point-time determinations of single-leaf-based WUE are extrapolated to the whole-canopy behaviour when assessing the water saving strategies of a given genotype. The stressed vines achieved no variation in yield level and components and had improved grape composition as to soluble solids and total anthocyanins. This optimal behaviour is likely due to earlier shoot growth cessation, enhanced maturity and a buffering leaf-to-fruit ratio (3.61 m² kg^?1) that mitigated the effects of post-veraison stress.