Nitrogen runoff from fertiliser intensive land uses has become an issue worldwide, contributing to algal blooms, hypoxic waters and aquatic biodiversity losses. This study assessed potential nutrient pollution from blueberry farms in subtropical Australia and examines whether nutrient loads were driven by groundwater discharge and/or surface water runoff. Streams downstream of eight blueberry farms were compared to eight nearby control sites without any blueberry activity. In the 90 day sample period, there were three rain events >90 mm day⁻¹ that produced runoff sufficient to create flooding. Overall, the results revealed a clear link between blueberry farming and nitrogen runoff in headwater streams. While NOX (nitrate + nitrite) was the dominant nitrogen species downstream of blueberry farms, dissolved organic nitrogen (DON) was the dominant species in control sites. The concentrations and loads of NOₓ were one order of magnitude lower in the eight non-blueberry (6.3 ± 2.0 μmol L⁻¹; 1.6 ± 1.2 kg N-NOX ha⁻¹ yr⁻¹) than the eight blueberry (56.9 ± 14.2 μmol L⁻¹; 21.8 ± 8.0 kg N-NOX ha⁻¹ yr⁻¹) sites. NOX concentrations and loads were highest following rain events. Radon (²²²Rn, a natural groundwater tracer) observations and low nitrogen concentration in groundwater samples further suggest that surface runoff dominates the delivery of nitrogen to the creeks investigated. NOX concentrations and loads in creeks correlated with blueberry farm density. At >15% of blueberry land use in a catchment, there was a detectable influence in NOX concentrations and loads in the headwater streams. Assuming that our load estimates can be up-scaled to annual nitrogen creek exports, and that local farmers use the recommended amount of fertiliser (121 kg N ha⁻¹ yr⁻¹), between 18 and 25% of the used fertiliser was lost to the creeks. This implies that there are opportunities for decreasing the use of fertilisers in this catchment and managing any nitrogen that escapes to the creeks.

Organic fertilizers, such as digestates and manure, are increasingly applied in agricultural systems because of the benefits they provide in terms of plant nutrients and soil quality. However, there are few investigations of N₂O emissions following digestate application to agricultural soils using process-based models. In this study, we modified the UK-DNDC model to include digestate applications to soils by adding digestate properties to the model and considering the effect of organic fertilizer pH. Using the modified model, N₂O emissions were simulated from two organic fertilizers (digested food waste and livestock slurry) applied to three farms in the United Kingdom: one growing winter wheat at Wensum (WE) and two grasslands at Pwllpeiran (PW) and North Wyke (NW). The annual cumulative gross (i.e. not excluding control emission) N₂O emissions were calculated using MATLAB trapezoidal numerical integration. The relative errors of the modeled annual cumulative emissions to the measured emissions ranged from −5.4% to 48%. Two-factor models, including linear, exponential and hyperbola responses, correlating total N loading and soil clay content to calculations of N₂O emissions and N₂O emission factors (EFs) were developed for calculations of emission fluxes and EFs. The squares of the correlation coefficients of the measured and two-factor linear modeled emissions were 0.998 and 0.999 for digestate and slurry, respectively, and the corresponding squares of correlation coefficients of the EFs were 0.998 and 0.938. The two-factor linear model also predicted that the EFs increased linearly with decreasing clay content and the maximum EFs for digestate and slurry were 0.95 and 0.76% of total N applied, respectively. This demonstrates that the modified UK_DNDC is a good tool to simulate N₂O emission from digestate and slurry and to calculate UK EFs using TIER 3 methodology..

Manure treatment technologies are rapidly developing to minimize eutrophication of surrounding environments and potentially decrease the introduction of antibiotics and antibiotic resistant genes (ARGs) into the environment. While laboratory and pilot-scale manure treatment systems boast promising results, antibiotic and ARG removals in full-scale systems receiving continuous manure input have not been evaluated. The effect of treatment on ARGs is similarly lacking. This study examines the occurrence and transformation of sulfonamides, tetracyclines, tetracycline degradation products, and related ARGs throughout a full-scale advanced anaerobic digester (AAD) receiving continuous manure and antibiotic input. Manure samples were collected throughout the AAD system to evaluate baseline antibiotic and ARG input (raw manure), the effect of hygenization (post-pasteurized manure) and anaerobic digestion (post-digestion manure) on antibiotic and ARG levels. Antibiotics were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the ARGs tet(O), tet(W), sul1 and sul2 were analyzed by quantitative polymerase chain reaction (Q-PCR). Significant reductions in the concentrations of chlortetracycline, oxytetracycline, tetracycline and their degradation products were observed in manure liquids following treatment (p < 0.001), concomitant to significant increases in manure solids (p < 0.001). These results suggest sorption is the major removal route for tetracyclines during AAD. Significant decreases in the epimer-to-total residue ratios for chlortetracycline and tetracycline in manure solids further indicate degradation is desorption-limited. Moreover, sul1 and sul2 copies decreased significantly (p < 0.001) following AAD in the absence of sulfonamide antibiotics, while tetracyclines-resistant genes remained unchanged. A cross-sectional study of dairy farms utilizing natural aeration and liquid-solid separation treatments was additionally performed to compare levels of antibiotics and ARGs found in AAD with the levels in common manure management systems. The concentration of antibiotics in raw manure varied greatly between farms while minimal differences in ARGs were observed. However, significant (p < 0.01) differences in the levels of antibiotics and ARGs (except tet(W)) were observed in the effluents from the three different manure management systems.

A high-resolution 3-D model was developed to assess the impact of a diversion outfall at the Tarumi Sewage Treatment Plant (TSTP) on an adjacent seaweed farm in Osaka Bay, Japan. The model was extensively validated to ensure a reasonable agreement with in situ observations. The western part of the farm is largely influenced by tidal currents, whereas the eastern area is mainly affected by subtidal residual currents that are primarily due to surface wind stress. The released effluent is transported by counterclockwise residual circulation formed off the TSTP. The model reveals that the diversion adequately suppresses the influence on the farm. While the instantaneous effluent concentration is diminished by about 50%, the effluent accumulated on the farm decreased from 2.83 × 104 m3 to 2.01 × 104 m3 due to the diversion, demonstrating an approximately 28% reduction of the effluent from the TSTP by the diversion outfall.

Environmental antimicrobial resistance (AMR) has drawn increasing attention due to its great risk to human health. The aim of this study was to investigate AMR and genotyping of Vibrio parahaemolyticus isolates (n = 114) recovered from shrimp mariculture environment in China. The isolates exhibited a high rate of resistance to streptomycin (78.9%), ampicillin (64.9%) and gentamicin (53.5%). Furthermore, multi-drug resistance was highly prevalent (61.4%), in which 95.9% of these ampicillin-resistant isolates were primarily mediated by blaCARB-17. Surprisingly, doxycylcine, florfenicol, and trimethoprim/sulfamethoxazole (TMP/SMZ) resistance genes occurred in susceptible isolates. Moreover, 114 isolates were grouped into unique pulsed field gel electrophoresis patterns. These findings suggest the need for the prudent use of antimicrobial agents on mariculture farms, in order to control the dissemination of antimicrobial resistant V. parahaemolyticus.

Marine renewable energy development raised concerns over the impact of underwater noise. Here we assess the acoustic impacts of an operating tidal current turbine (Paimpol-Bréhat site, France) on marine fauna. Its source level (SL) has been measured in situ using 19 drifting transects at distances between 100 m to 2400 m from the turbine. SL ranged from 118 to 152 dB re1 μPa@1 m in third-octave bands at frequencies between 40 and 8192 Hz. It is comparable to the SL of a 19 m boat travelling at 10kt speed. This SL was used to estimate the impact of this noise type based on acoustic propagation simulations. The acoustic footprint of the device corresponds to a 1.5 km radius disk. Our results show that within this area of greatest potential impact, physiological injury of the hearing apparatus of invertebrates, fishes and marine mammals is improbable. Behavioral disturbance may occur up to 1 km around the device for harbor porpoises only. This is of little concern for a single turbine. However, greater concern on turbine noise impact, particularly on behavioral reactions has to be granted for a farm with up to 100 turbine. The lack of consolidated knowledge on behavioral disturbances identifies the needs for specific research programs.

Biochemical and molecular responses were evaluated in oysters Crassostrea brasiliana collected from three oyster farms, at Guaratuba Bay, southern Brazil, forming a pollutant gradient: Farm 1 (reference site - farther from the urban area), Farm 2 (intermediate site) and Farm 3 (nearest to the urban area). Oxidative stress markers, DNA damage and transcript levels of CYP2AU1, CYP2-like1, CYP2-like2, SULT-like, GPx-like, SOD-like, CAT-like, GSTmicrosomal-like, GSTomega-like, FABP-like and ALAd-like genes were analyzed in the gills. The levels of polycyclic aromatic hydrocarbons, linear alkylbenzenes and polychlorinated biphenyls were also evaluated in the soft tissues of the oysters and in the sediment of the Farms. Higher GSTomega-like, CYP2AU1 and FABP-like transcript levels, GR and G6PDH activities and lipid peroxidation levels were observed in oysters from Farms 2 and 3, suggesting pollutant effects on oysters. Alterations in oxidative stress markers also suggest a response against a prooxidant condition in C. brasiliana due to pollutant effects.

Even if it is less polluting than other farm sectors, grape growing management has to adopt measures to mitigate greenhouse gas (GHG) emissions and to preserve the quality of grapevine by-products. In viticulture, by land and crop management, GHG emissions can be reduced through adjusting methods of tillage, fertilizing, harvesting, irrigation, vineyard maintenance, electricity, natural gas, and transport until wine marketing, etc. Besides CO₂, nitrous oxide (N₂O) and methane (CH₄), released from fertilizers and waste/wastewater management are produced in vineyards. As the main GHG in vineyards, N₂O can have the same harmful action like large quantities of CO₂. Carbon can be found in grape leaves, shoots, and even in fruit pulp, roots, canes, trunk, or soil organic matter. C sequestration in soil by using less tillage and tractor passing is one of the efficient methods to reduce GHG in vineyards, with the inconvenience that many years are needed for detectable changes. In the last decades, among other methods, cover crops have been used as one of the most efficient way to reduce GHG emissions and increase fertility in vineyards. Even if we analyze many references, there are still limited information on practical methods in reducing emissions of greenhouse gases in viticulture. The aim of the paper is to review the main GHG emissions produced in vineyards and the approached methods for their reduction, in order to maintain the quality of grapes and other by-products.

Coastal saline rice fields play an increasingly important role in rice production and associated greenhouse gas (GHG) emissions. However, few studies investigated the influences of nitrogen (N) fertilizer and soil ameliorant on GHG emissions simultaneously in this region. Thus, a field experiment was established to study the effects of different N fertilizers and soil ameliorant on global warming potential (GWP) and yield-scaled GHG intensity (GHGI) after accounting for carbon dioxide (CO₂) equivalent emissions of methane (CH₄) and nitrous oxide (N₂O), agrochemical inputs, and farm operations along with agronomic nitrogen use efficiency (NUE) during the rice season of 2016 in a coastal saline paddy in Lianyungang, China. The experiment was initiated with four N treatments (N0, no N; Nu, urea; Nm, organic-inorganic mixed fertilizer; Nw, organic fertilizer made from wheat straw) and two ameliorant (A) treatments (A0, no ameliorant; A1, 22.5 kg ha⁻¹ ameliorant). The results showed that three N fertilizers significantly increased the CH₄ emissions, N₂O emissions, GWP, and grain yield by 42.2% (p < 0.001), 57.1% (p < 0.001), 49.8% (p < 0.001), and 58.9% (p < 0.001), respectively. NuA1, NmA1, and NwA1 treatments obviously reduced the yield-scaled GHGI by 21.3%, 16.3%, and 12.4%, respectively, relative to the corresponding NuA0, NmA0, and NwA0 treatments. Overall, although three N fertilizers would increase the GWP, combining an ameliorant amendment with N fertilizer can effectively reduce the yield-scaled GHGI and meanwhile increase the grain yield, particularly the NmA1 strategy.

World recent concerns about the shortage of water resources and contamination of groundwater supplies have motivated scientists seeking for more efficient techniques in irrigation and fertilization of farms while taking the advantage of models. The objective of this study is to address how water and nitrogen (N) dynamics are affected by efficient management strategies and to evaluate the application of HYDRUS-1D model in these conditions. In terms of using management policies, different irrigation strategies, planting methods, and different N fertilization rates applied on safflower (Carthamus tinctorius L.) in volumetric field lysimeters. The irrigation regimes were ordinary furrow irrigation (OFI) and variable alternate furrow irrigation (VAFI) as a partial root drying (PRD) technique. The planting methods were on-ridge planting (P1) and in-furrow planting (P2) methods. The fertilizer levels were 0 (N0), 100 (N1), and 200 (N2) kg ha⁻¹ of urea as 0, 46, and 92 kg N ha⁻¹. Results showed that VAFI regime and in-furrow planting method favorably reduced the amount of drainage water below safflower root zone in comparison with the ordinary methods. Furthermore, VAFI regime satisfactorily decreased the seasonal nitrate (NO₃-N) leaching below the root zone, whereas differences between the leached NO₃-N in in-furrow and on-ridge planting methods were not significant. Moreover, VAFI regime did not show any negative effects on total N uptake in safflower seed and straw, whereas in-furrow planting accumulated higher N in comparison with the on-ridge planting method. In addition, safflower nitrogen (N) uptake was responsive to application of nitrogen, although the rate of increase in N accumulation was not significant between the application rates of 46 and 92 kg N ha⁻¹. The soil nitrate concentration decreased during the growing season indicating that safflower root system has a great ability in absorption of NO₃-N from soil N supplies. HYDRUS-1D model favorably predicted the drainage water, nitrate concentration of drainage water, crop N uptake, and residual soil NO₃-N concentration for safflower field. Therefore, it can be an applicable model for prediction of water and nitrogen dynamics, despite of two-dimensional flow conditions in furrow irrigation. It was concluded that VAFI strategy and in-furrow planting method are suitable alternatives helping farmers produce food while conserving water and preserving the environment.