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There is a worldwide focus on reducing the environmental impacts of livestock manure management. In China, there are different manure treatment and application modes, including complete treatment to remove nitrogen (N) for direct discharge into watercourses. But we lack a systematic quantitative comparison of the environmental losses that occur from different management modes. We used an example farm of 10,000 finisher pigs to quantitatively analyze the annual N losses from land application (LA) and treatment to remove N from manure to the level of discharge consent (DS) under 24 sub-modes. This is an important study to unravel the effect of choice of different manure management systems on subsequent N losses. The results showed that the N losses from the LA mode (52.6% of total N excretion) were significantly lower than that from the DS mode (75.9%). Compared with other sub-modes, N emission from whole slurry injection was the smallest, accounting for 43.2% of total N excretion. NH 3 –N was the main source of N loss which accounted for 72.9% and 50.2% in LA and DS mode, respectively. The lowest N emission of LA mode with mitigation options, including slurry store covers, composting with bio-filter deodorization and injection application, was 28.8% of total N excretion, which is only 42.2% of N emission from DS mode with mitigation options. Insights from this systematic study of different manure management modes in China show the imperative of control ammonia emission for China, and provide guidance to the sustainable manure management in rapidly developing countries. [Display omitted] • The N losses from 24 manure management sub-modes were quantitative assessed. • N losses from land application model were 30% lower than standard discharge model. • Gaseous emissions were the main loss pathway in which NH 3 –N was the main source. • Policy and technology guidance should focus on NH 3 mitigation in key stages. [ABSTRACT FROM AUTHOR]

Increasing tropospheric ozone poses a potential threat to both above- and belowground components of the terrestrial biosphere. Microorganisms are the main drivers of soil ecological processes, however, the link between soil microbial communities and ecological functions under elevated ozone remains poorly understood. In this study, we assessed the responses of three crop seedlings (i.e., soybean, maize, and wheat) growth and soil microbial communities to elevated ozone (40 ppb O 3 above ambient air) in a pot experiment in the solardomes. Results showed that elevated ozone adversely affected ecosystem multifunctionality by reducing crop biomass, inhibiting soil extracellular enzyme activities, and altering nutrient availability. Elevated ozone increased bacterial and fungal co-occurrence network complexity, negatively correlated with ecosystem multifunctionality. Changes in the relative abundance of some specific bacteria and fungi were associated with multiple ecosystem functioning. In addition, elevated ozone significantly affected fungal community composition but not bacterial community composition and microbial alpha-diversity. Crop type played a key role in determining bacterial alpha-diversity and microbial community composition. In conclusion, our findings suggest that short-term elevated ozone could lead to a decrease in ecosystem multifunctionality associated with changes in the complexity of microbial networks in soils. • Elevated ozone reduced ecosystem multifunctionality. • Changes in microbial community composition were linked to ecosystem functioning. • Elevated ozone negatively affected crop seedling growth and soil microbial activity. • Crop type shaped soil microbial community composition. [ABSTRACT FROM AUTHOR]

Eutrophication is a major water pollution issue and can lead to excessive growth of aquatic plant biomass (APB). However, the assimilation of nutrients into APB provides a significant target for their recovery and reuse, and harvesting problematic APB in impacted freshwater bodies offers a complementary approach to aquatic restoration, which could potentially deliver multiple wider ecosystem benefits. This critical review provides an assessment of opportunities and risks linked to nutrient recovery from agriculturally impacted water-bodies through the harvesting of APB for recycling and reuse as fertilisers and soil amendments. By evaluating the economic, social, environmental and health-related dimensions of this resource recovery from ‘waste’ process we propose a research agenda for closing the loop on nutrient transfer from land to water. We identify that environmental benefits are rarely, if ever, prioritised as essential criteria for the exploitation of resources from waste and yet this is key for addressing the current imbalance that sees environmental managers routinely undervaluing the wider environmental benefits that may accrue beyond resource recovery. The approach we advocate for the recycling of ‘waste’ APB nutrients is to couple the remediation of eutrophic waters with the sustainable production of feed and fertiliser, whilst providing multiple downstream benefits and minimising environmental trade-offs. This integrated ‘ecosystem services approach’ has the potential to holistically close the loop on agricultural nutrient loss, and thus sustainably recover finite resources such as phosphorus from waste. [ABSTRACT FROM AUTHOR]

Dairy cattle housing is a significant source of NH3 and GHG emissions to atmosphere. However, the climate, temperature in particular, and the characteristics of the excreta of the housed cattle, may have a strong influence on the magnitude of such emissions. The objectives were to assess the effects of temperature and excreta characteristics of heifers, dry cows and lactating cows on potential NH3, N2O, CO2 and CH4 emissions. The experiment was conducted using laboratory chambers where constant amounts of urine and faeces were applied to a concrete floor. Potential NH3 and GHG emissions were measured over 120-h following application at 5, 15, 25 and 35 °C. Increasing temperature promoted a significant increase in NH3 emissions. At temperatures ≥15 °C, total NH3 emissions accounted for more than 100% of the urea–N content of the urine for the three dairy cattle types, indicating that other organic N compounds of urine and faeces are an important source of NH3. The cumulative amount of N2O released did not vary significantly with temperature and ranged from 1 to 2% of total N deposited. Cumulative CO2 emissions were ca. 14–58% of total C deposited and the cumulative CH4 emissions were significantly higher at 25 °C than at all other temperatures. It was concluded that increasing temperature from 5 to 35 °C significantly increased potential NH3, CO2 and CH4 emissions but did not significantly influence N2O emissions. Also, the diet supplied to lactating cows led to significantly higher NH3, N2O and CO2 emissions relative to heifers and dry cows. [Copyright &y& Elsevier]

Advanced slurry processing (anaerobic digestion, acidification and separation) is being promoted to generate renewable energy, reduce ammonia emissions and optimise storage and transport, respectively. However, these processes could affect slurry phosphorus (P) forms and bioavailability, and hence P dynamics in soil after application. This study investigated the effect of slurry processing, viz. separation, acidification and anaerobic digestion on P forms and distribution of cattle slurry, as well as P dynamics in soil following application of mechanically separated solid and liquid cattle slurry. The results showed that acidification and anaerobic digestion had little impact on TP distribution among particle fractions of slurry, but had substantial influence on P speciation and distribution. Acidification increased the dissolved inorganic-P (IP–H 2 O) proportion in cattle slurry, by reducing the mineral surface adsorbed (IP–NaHCO 3) and precipitated inorganic P (IP–HCl) proportion. Anaerobic digestion decreased OP-NaHCO 3 proportion by degradation and increased the IP-NaHCO 3 and IP-HCl proportion by adsorption and precipitation. Particles <63 μm accounted for over 65% of P present in cattle slurry. The above changes in whole slurry made by acidification and anaerobic digestion were dominated by the <63 μm fraction. Slurry-derived soluble inorganic-P in soil decreased with time, due to adsorption and microbial immobilisation. This decrease was slower in the soil amended with anaerobically digested slurry. Results suggest that anaerobic digestion and acidification change P speciation of separated solid and liquid slurry and the subsequent P dynamics in soil after application. • Acidification increased labile inorganic P in cattle manure by dissolution. • Anaerobic digestion increased labile inorganic P in cattle manure by degradation. • Particles <63 μm accounted for the majority of P present in cattle manure. • Anaerobic digestion increased mass proportion of the <63 μm particles. • Slurry processing controls soluble P in soil, but not the moderately labile P. [ABSTRACT FROM AUTHOR]

This chapter reviews contributions made to agricultural and environmental science and practice from research on temperate grassland carried out from 1982 to present at Rothamsted Research's North Wyke Research Station, Devon, UK. It describes the evolution of the research program and demonstrates the importance of sustained, interdisciplinary, and collaborative research. North Wyke has maintained a clear research focus, alongside an ability to adapt to changing grassland and environmental research needs and funding sources, and despite having changed affiliations on several occasions. The substantial contribution to agricultural and environmental science arising from the research station has influenced and continues to influence farm practice, research, and policy nationally and internationally. Some key topics have included nutrient cycling, farm waste management, gaseous emissions, biodiversity, grazing management, animal production (meat and milk), and forage quality. Currently, North Wyke Research Station is leading the way on taking increasingly holistic approaches to researching more efficient, sustainable approaches to grazing-livestock agricultural production. This involves the use of world-leading, facilities such as the North Wyke Farm Platform, comprising three farmlets, designed to test the productivity and environmental sustainability of contrasting temperate grassland beef and sheep systems. Future perspectives highlight key challenges facing the agricultural industry including climate change mitigation and adaptation, and the growing world population. Opportunities exist to tackle these challenges through technological advances, but also through increased integration of agricultural, environmental, economic and social research. North Wyke Research Station provides an example of a research facility where such challenges can be addressed. [ABSTRACT FROM AUTHOR]

Dairy farming generates large volumes of liquid manure (slurry), which is ultimately recycled to agricultural land as a valuable source of plant nutrients. Different methods of slurry application to land exist; some spread the slurry to the sward surface whereas others deliver the slurry under the sward and into the soil, thus helping to reduce greenhouse gas (GHG) emissions from agriculture. The aim of this study was to investigate the impact of two slurry application methods (surface broadcast versus shallow injection) on the survival of faecal indicator organisms (FIOs) delivered via dairy slurry to replicated grassland plots across contrasting seasons. A significant increase in FIO persistence (measured by the half-life of E. coli and intestinal enterococci) was observed when slurry was applied to grassland via shallow injection, and FIO decay rates were significantly higher for FIOs applied to grassland in spring relative to summer and autumn. Significant differences in the behaviour of E. coli and intestinal enterococci over time were also observed, with E. coli half-lives influenced more strongly by season of application relative to the intestinal enterococci population. While shallow injection of slurry can reduce agricultural GHG emissions to air it can also prolong the persistence of FIOs in soil, potentially increasing the risk of their subsequent transfer to water. Awareness of (and evidence for) the potential for ‘pollution-swapping’ is critical in order to guard against unintended environmental impacts of agricultural management decisions. [ABSTRACT FROM AUTHOR]

Dairy cattle are usually housed in naturally ventilated houses where removal of excreta is periodically performed. The aim of this controlled study was to compare the effect of two floor designs and three air temperatures (5, 15 and 25 °C) on NH3, N2O, CH4 and CO2 emissions arising from cattle excreta deposition to the floor. Two scale models were built to simulate a level solid floor without urine drainage, and a slatted concrete floor. Following application of a mixture of urine and faeces, these two floor type models were subjected to a constant airflow rate (12.5 exchanges h−1) and gaseous emissions were measured over a 72-h period. Emissions of NH3, N2O, CO2 and CH4 increased significantly with air temperature with both floor type models and emissions of NH3, N2O and CO2 were significantly greater from the solid floor relative to the slatted floor at all temperatures considered. The cumulative NH3 (27–66% of total N applied) and CO2 (<19% of total C applied) emissions were greater from the solid floor than from the slatted floor (by 36% and 44%, respectively). The cumulative N2O (<0.1% of total N applied) and CH4 (<0.4% of total C applied) emissions were relatively low and CH4 values did not differ significantly between treatments. Cumulative greenhouse gas emissions (as CO2-equivalents) increased significantly with temperature but did not differ between the floor types. [ABSTRACT FROM AUTHOR]

To successfully curb microbial contamination of surface waters we need to understand, and holistically evaluate, the range of mitigation strategies that have been designed to protect watercourses from nonpoint agricultural sources, so as to use them to best effect. A cost-effective and pragmatic approach is to improve knowledge of farm management operations capable of (1) reducing potential pathogen numbers in livestock manures and (2) reducing subsequent transfer (through the environment) of fecal microorganisms derived from livestock manures that are recycled to land. This will prove important for supporting farmer decision making, devising policy, and implementing mitigation practices to limit fecal microorganism delivery from land to water. In this chapter, we consider a diverse suite of manure, animal, and land management options that range from simple manure-composting techniques and the use of slurry additives, through to land management engineering approaches and the design of constructed wetlands to protect watercourses from microbial contamination. The choice as to which strategy to use, if any, is ultimately made by the farmer and is likely to be influenced by a complex range of factors which may include, for example, tradition, convenience, and farm economics. We conclude that the inherent complexity associated with heterogeneous landscapes confounds the likelihood that a single management strategy will provide complete protection of receiving waters from microbial contamination. Instead, the coupling of different strategies alongside improved education and considerable vigilance by farmers and landowners is needed for a more sustainable approach to limiting diffuse microbial (and, crucially, other contaminant) pollution from agriculture. [ABSTRACT FROM AUTHOR]