Bird community responses to cattle stocking rates in a Pacific Northwest bunchgrass prairie

In 2006-2010, effects of four different cattle stocking rates (0, 14.4, 28.8, and 43.2 animal unit months) were compared, representing 0%, 20%, 32%, and 46% utilization of vegetation by domestic livestock, on vegetation structure (as indexed by visual obstruction), and songbird population and apparent nest density, community composition, and diversity in a Pacific Northwest bunchgrass prairie in northeastern Oregon, USA. Overall paddock-level visual obstruction decreased and structural heterogeneity increased with increasing stocking rates, and those effects carried over 1 year after grazing had ceased. Most species were able to locate nesting sites regardless of differences in visual obstruction, except western meadowlark and vesper sparrow, for which obstruction was lower in paddocks with higher stocking rates. Apparent nest density for grasshopper sparrows was negatively affected by higher stocking rates. Grazing effects on absolute songbird population density were restricted to negative effects of higher stocking rates on savannah sparrows, but this relationship was not observed until 1 year after grazing had ceased. Songbird community composition differed between control and heavily-grazed paddocks, driven by an increase in the proportion of horned larks and a decrease in the proportion of savannah sparrows in heavily-grazed paddocks from pre-treatment to post-treatment years. Bird diversity indices were unaffected by stocking rate. Negative effects of high stocking rates on densities of two species and the absence of any clear positive effect for the other three species suggest high stocking rates as applied in this experiment may not provide suitable habitat for all grassland songbirds. The absence of negative responses of density to low and moderate stocking rates suggests these grazing regimes generally provided suitable habitat for all species.     

Adaptation to climate change: changes in farmland use and stocking rate in the U.S.

This paper examines possible adaptations to climate change in terms of pasture and crop land use and stocking rate in the United States (U.S.). Using Agricultural Census and climate data in a statistical model, we find that as temperature and precipitation increases agricultural commodity producers respond by reducing crop land and increasing pasture land. In addition, cattle stocking rate decreases as the summer Temperature-humidity Index (THI) increases and summer precipitation decreases. Using the statistical model with climate data from four General Circulation Models (GCMs), we project that land use shifts from cropping to grazing and the stocking rate declines, and these adaptations are more pronounced in the central and the southeast regions of the U.S. Controlling for other farm production variables, crop land decreases by 6 % and pasture land increases by 33 % from the baseline. Correspondingly, the associated economic impact due to adaptation is around ?14 and 29 million dollars to crop producers and pasture producers by the end of this century, respectively. The national and regional results have implications for farm programs and subsidy policies.     

Effects of cattle,sheep and deer grazing on soil physical quality and losses of phosphorus and suspended sediment losses in surface runoff

Livestock grazing and treading is strongly linked to a decrease in freshwater quality and promotes eutrophication. A two-year field trial was carried out to investigate the influence cattle, sheep and deer have on soil physical quality and the loss of phosphorus (P) and suspended sediment (SS) in surface runoff. Surface runoff plots (4 m long by 1 m wide) were installed within areas designated as stock or ungrazed (control). Surface runoff was collected and analysed for concentrations and loads of P fractions (dissolved reactive P-DRP, dissolved unreactive P-DUP, total dissolved P-TDP, particulate P-PP and total P-TP) and SS. Grazed at equivalent stocking density, soil physical samples (macroporosity, bulk density, and saturated hydraulic conductivity K_sat) were taken after each grazing event (n = 11). Soil physical data indicated differences between cattle, sheep and deer with cattle having greater negative effects. However, these differences had no impact on P and SS losses between stock types in surface runoff. Significant relationships showed that an increase in macroporosity, K_sat, and time (days) since grazing decreased concentrations and loads of P and SS losses. A separate rainfall simulation study also revealed that an increase in simulated cattle treading intensity increased the volume of surface runoff and SS losses. Most surface runoff (> 90%) occurred in winter when soil moisture was at or above field capacity. A seasonal effect was observed and showed that although the greatest P loads occurred in winter, the greatest P concentrations occurred in summer months, under infiltration-excess conditions. These summer losses could pose a risk to receiving waterways because increased light and warmth may induce an algal response compared to winter. While there is limited scope to manage for infiltration-excess surface runoff losses from pasture, with most runoff occurring in winter, these findings reinforce the use of mitigation strategies such as restricted or nil grazing in winter when soil moisture has reached field capacity to minimise P and SS loss to surface water, regardless of stock type.     

The impact of increasing the length of the cattle grazing season on emissions of ammonia and nitrous oxide and on nitrate leaching in England and Wales

Ammonia (NH₃) emissions from cattle are much less when they are grazing than when they are housed. The urine excreted during grazing may rapidly infiltrate soil whereas it remains on the surface of impermeable floors and yards. If the average grazing season for the UK herd could be extended from 6 to 8 months, NH₃ emissions from cattle could potentially be reduced by ca. 15% (of the total for all livestock) if the cattle spend all of the extra grazing days outdoors. The main objective of this desk study was to assess the potential of extended season grazing to reduce NH₃ emissions from UK cattle farming. The impacts on nitrate (NO₃⁻) leaching and nitrous oxide (N₂O) emissions were also estimated. A simple process-based model was developed to quantify the potential for extending the grazing season. A farm-scale model of NH₃ emissions at the farm-scale, based on published emission factors for UK agriculture, was used to estimate NH₃ emissions. Losses of NO₃⁻ following slurry spreading were estimated using the MANNER model, while NO₃⁻ leaching and denitrification losses during grazing were taken from output by the NGAUGE model. We conclude that one month’s extra grazing (based on the animals being outside for all of that month, day and night,) may reduce NH₃ emissions from slurry-based systems by ca. 9% and for FYM-based systems by ca. 7% compared with losses from the current ca. 180-day winter housing period. However, in practice cattle are not outdoors all day during the extended grazing period. If it is assumed that cattle graze for an average of 4 h per day over the extended period, then the monthly reduction in NH₃ emissions may be only ca. 1–2%. At all sites most of this conserved N was predicted to be lost as NO₃⁻. For slurry-based systems this could be at least 80%. For FYM-based systems, for which there was less potential to conserve NH₃, the increase in NO₃⁻ leaching was always greater than the NH₃ conserved. The effects on direct emissions of N₂O were estimated be negligible, if grazing began earlier in spring or perhaps some reduction when grazing continues for longer in autumn. We conclude that extending the grazing season will increase NO₃⁻ leaching and that further studies are needed to fully evaluate the potential for reducing emissions of NH₃.     

Effects of grazing intensity and prescribed fire on soil physical and hydrological properties and pasture yield in the savanna woodlands of Burkina Faso

In West Africa policies for prescribed early fire and livestock grazing in the savanna woodlands are rarely based on long-term experimental studies. The inherently different management characteristics and their effects on the vegetation dynamics make landscape degradation a contentious issue. The effects of grazing intensity were investigated by a comparison of non-grazed areas, lightly grazed areas, moderately grazed areas, heavily grazed areas and very heavily grazed areas that received one of two fire treatments: early burning and fire protection in a long-term 12-year study. The parameters assessed reflected changes in herbaceous plant cover, biomass as well as soil physical and hydrological properties. The main findings were by and large specific for the grazing level. This supports the argument for devolution of management responsibility to the local level where there is indigenous site-specific knowledge but at the same time insufficient management capacity.A comparison of composite soil samples taken at a depth of 0–10 cm did not differentiate significantly between treatments. This is probably because the composite soil sampling procedure hid the properties of the top first few centimeters. Grazing pressure had a tendency to reduce total above ground biomass (p = 0.081). This was related to increased biomass removal and the trampling pressure (static load) exerted by the animals. The infiltration measurements indicated that the deleterious impact of cattle trampling increased as stocking rate increased. Livestock grazing significantly (p = 0.038) lowered the infiltrability. Prescribed early fire had a tendency (p = 0.073) to reduce the soil water infiltration rate. The subplots subjected to prescribed burning had a lower steady state infiltration rate compared to unburnt areas (means of 49.2 ± 27.5 mm h⁻¹ versus 78 ± 70.5 mm h⁻¹ for burnt and unburnt subplots, respectively). A partial least squares projection to latent structures showed that 34% of the steady state infiltrability was explained by the stocking rate and soil organic matter. Also all soil characteristics were significantly connected to steady state infiltrability suggesting that they are related to the soil hydrological response to trampling.From a management perspective, adoption of a short duration grazing system should avoid high stocking rates because they may adversely affect soil infiltrability, increase susceptibility to erosion in the savannas and decrease biomass productivity.     

Development of the Pasture Simulation Model for assessing livestock production under climate change

To simulate climate change impacts on pastures and domestic herbivores as well as feedbacks to the atmosphere in terms of greenhouse gas emissions, we have improved a process-based biogeochemical pasture model, PaSim. The overall aim was to simulate the meat and milk production of cattle (suckler cows with their calves, dairy cows and heifers) in response to climate and management, as well as feedbacks to the atmosphere through enteric methane emissions. Herbage intake at grazing was calculated from animal characteristics, herbage availability, diet digestibility and air temperature. With suckler cows, milk production and changes in daily liveweight and body condition were calculated from net energy balance. The net energy intake of dairy cows and their body reserves at turnout to pasture were used to simulate milk production at pasture, daily liveweight and body condition changes, taking into account cow energy requirements and intake capacity. Heifer growth was determined from heifer net energy intake and liveweight. Net energy intake was used to assess enteric methane production through a conversion factor, which depends both on the energy level of the diet and on the herbivore type. The model was assessed against experimental data for animal performance and methane emissions at grazing. Predictions show good agreement with observations. On average, the root mean square error was 6.5, 4 and 2.5% for the liveweights of suckler cows, suckler calves and heifers, respectively, 18% for dairy milk production and 12% for enteric methane emissions. By comparing this new version of the PaSim model to the previous version, we show that a greater accuracy in animal performance modelling improves the sensitivity of the model to interannual climate variability. However, long term (30 years) projections of climate change impacts on grasslands and of radiative feedbacks to the atmosphere are not significantly modified. The originality and the validity domain of the model are discussed.     

Impact on sward composition and stock performance of grazing Molinia-dominant grassland

A comparative experiment was conducted to test the extent to which grazing of rank Molinia caerulea-dominated grassland increases botanical diversity and improves animal performance. The study was carried out on an area of under-grazed Molinia-dominant pasture that had not been stocked for 20 years. Three treatments were compared from 2001 until 2008: (1) no grazing, (2) grazing by Welsh Mountain sheep and (3) grazing by Welsh Black heifers. Patterns of change in sward surface composition across the grazing season were consistent with greater consumption of Molinia by the cattle, but there was little evidence of management regime influencing changes in sward composition year-on-year. There was a significant effect of year on animal performance (P < 0.001). Although the growth rates of the heifers improved over the course of the first three years of the experiment, this performance was not sustained. In contrast, any weight changes for the sheep were positive. The results highlight the slow pace of change within upland swards, and the need to develop site-specific grazing guidelines.     

Nitrogen use efficiency: A potential performance indicator and policy tool for dairy farms

Escalating fertilizer and feed costs, declining product prices, and increasing regulations to reduce environmental pollution have created new pressures to improve nutrient use in agricultural production. This study provides an overview of factors and processes that impact nitrogen use efficiency (NUE) in dairy production, identifies practices that may bridge gaps between actual-NUE obtained on commercial farms and potential-NUE obtained under experimental conditions, and explores the possibility of using NUE as a performance indicator and policy tool for dairy production. Actual feed-NUE varies from 16% to 36% and is impacted by of a range of dairy practices; manure/fertilizer-NUE varies from 16% to 77% and is very site-specific; and whole-farm NUE varies from 8% to 64% and declines as stocking rates increase. Optimal stocking rate and manure nitrogen (N) crediting can enhance NUE, increase farm profits, and reduce N loss from dairy farms. NUE could be used to further engage dairy producers in collaborative assessments of gaps between their actual N use and the biological potential of N use, to develop performance goals for N use in various production components, and to monitor and evaluate the impacts of alternative feed, manure and fertilizer management practices on N use, profitability, and environmental outcomes.     

The influence of operational flexibility on the exploitation of CO2 reduction potential in industrial energy production

Energy conservation is a key measure for reducing CO₂ emissions. However, realising the emission reduction potential of an energy conservation investment depends on many factors, such as energy prices. The EU emissions trading scheme has made the investment analysis more complicated and increased the economic value of operational flexibility under fluctuating carbon prices. The different operational options in industrial energy production complicate the estimation of CO₂ reduction potential in the investment phase. Increasing operational flexibility enables optimisation in the economic dimension, which may lead to less than optimum CO₂ reduction. In our case study, which analysed the effects of an energy conservation investment made in the pulp and paper industry, the deviation from the expected emission reduction was around 30% over the period from 2000 to 2007. However, it seems that with high carbon prices, increasing operational flexibility has no significant effect on the carbon emissions. In policy-making, the freedom of action that is made possible by increasing operational flexibility should be taken into account when evaluating the contribution of an individual energy efficiency investment towards meeting the national targets for energy efficiency improvement and CO₂ emission reduction.     

Selection of cost-effective magnesium sources for fluidized struvite crystallization

Struvite crystallization has been considered a promising approach to recover phosphorus from wastewater. However, its practical application is limited, probably because of the high cost of magnesium(Mg). In this study, a comprehensive economic analysis was conducted using five Mg sources(MgCl_2, MgSO_4, MgO, Mg(OH)_2, and bittern) during the operation of a pilot-scale fluidized bed reactor(FBR), using swine wastewater as the case matrix. First, the economic operating conditions were investigated, and subsequently, the performance and the costs of the five Mg sources were compared. The results indicated that the FBR could be operated most economically at pH of 8.5 and Mg to phosphorus(Mg/P) molar ratio of 1.5. Under these conditions, no significant differences in phosphorus removal and product quality could be found between the five Mg sources. Selecting the most economical Mg source was thus highly dependent on the prices of the reagents and Mg sources. Low-solubility Mg sources were preferable when NaOH was priced higher, while high-solubility Mg sources proved more economical when HNO_3 was expensive. The bittern was the most economical choice only when the distances for total inorganic orthophosphate removal and struvite recovery were shorter than 40 and 270 km, respectively. The current study provides an overview of the economic selection of an Mg source, which can help reduce the cost of struvite crystallization.     

Effects of management intensity on land snails in Swiss nutrient-poor pastures

The influence of management intensity on the richness, abundance and composition of land snail species was examined in 21 calcareous, nutrient-poor cattle pastures in the northwestern Jura mountains, Switzerland. Grazing intensity was positively correlated with the extent of fertilization of the pastures. Pastures without fertilizer application and with low grazing intensity harboured more snail species and more threatened snails than pastures with annual addition of manure or pastures with manure and nitrogen fertilizer and higher grazing intensity. Fewer snail individuals, open-land species and open-land individuals were found on pastures with high than on pastures with low management intensity. To preserve the threatened snail species in dry, nutrient-poor grasslands, a network of pastures should be managed without fertilization and grazing intensity should not exceed 180 LU ha⁻¹ d (product of livestock units per hectare and grazing days).     

生物海绵铁体系降解硝基苯的特性及机理初探

采用硝基苯（NB）模拟废水对生物海绵铁体系进行驯化,考察了NB初始浓度、海绵铁投加量、初始pH值、温度等因素对生物海绵铁体系降解NB的影响,初步探讨了生物海绵铁体系高效降解NB的机理.结果表明：生物海绵铁体系较普通活性污泥系统对NB适应性及氧化作用更强,驯化至第28d对300mg/L NB废水去除率稳定在98%以上,驯化周期比普通活性污泥体系缩短28d;海绵铁的加入大大促进了微生物对NB的降解,NB初始浓度及pH值对生物海绵铁体系降解速率影响较大,该体系适宜的温度范围较广,10~40℃均能高效降解NB,生物海绵铁体系对NB的降解符合零级反应动力学规律;生物海绵铁体系中活性氧化物（ROS）含量明显高于海绵铁体系及污泥体系,尤其是介入铁泥的生物海绵铁体系ROS含量更高,为体系发生较强类Fenton效应提供了条件.在实验确定的最佳工况下,经NB驯化的铁泥与海绵铁形成的生物海绵铁体系,NB降解速率为31.49min^-1,6hNB降解率及TOC去除率分别高达92.0%和63.1%,较单独海绵铁体系与单独铁泥体系降解率的叠加值分别高出22.3%和11.4%.本研究为经济有效地处理NB废水提供了新思路.     

Effect of dung deposition on small-scale patch structure and seasonal vegetation dynamics in mountain pastures

Cattle activity greatly influences plant species composition and biomass production of grassland ecosystems. Dung deposition by cattle together with grazing and trampling can be considered as one of the important factors driving vegetation dynamics in pastures. The objective of this study was to investigate at 10-cm and 1-month resolution the plant community dynamics induced by dung deposition in two plant communities (a mesotrophic and an oligotrophic grassland) in a pasture of the Swiss Jura Mountains. Vegetation was sampled four or three times during the vegetation period in contiguous 10 cm × 10 cm quadrats from the centre of the dung pat to a distance of 60 cm. A lower grazing intensity near the dung pat was recorded for all observation periods. In the mesotrophic grassland the canopy was higher near the dung pat already one week after dung deposition. Vegetation around dung pats was submitted to two opposite fertilizing and grazing gradients, which induced changes in vegetation texture and structure at fine scale and short term. We observed a positive rank correlation between species turnover and distance to the dung for both communities, suggesting a seasonal stabilizing effect of dung on the plant composition of their direct surroundings (0–10 cm) likely due to cattle avoidance. Since dung pats are dropped every year in different locations, they create in the pasture a shifting mosaic of nutrient availability and grazing intensity inducing at seasonal scale micro-successions in plant communities.     

Marginal costs of abating greenhouse gases in the global ruminant livestock sector

Livestock [inclusive of ruminant species, namely cattle (Bos Taurus and Bos indicus), sheep (Ovis aries), goats (Capra hircus), and buffaloes (Bubalus bubalis), and non-ruminant species, namely pigs (Sus scrofa domesticus) and chickens (Gallus domesticus)] are both affected by climate change and contribute as much as 14.5 % of global anthropogenic greenhouse gas (GHG) emissions, most of which is from ruminant animals (Gerber et al. 2013). This study aims to estimate the marginal costs of reducing GHG emissions for a selection of practices in the ruminant livestock sector (inclusive of the major ruminant species—cattle, sheep, and goats) globally. It advances on previous assessments by calculating marginal costs rather than commonly reported average costs of abatement and can thus provide insights about abatement responses at different carbon prices. We selected the most promising abatement options based on their effectiveness and feasibility. Improved grazing management and legume sowing are the main practices assessed in grazing systems. The urea (CO(NH₂)₂) treatment of crop straws is the main practice applied in mixed crop–livestock systems, while the feeding of dietary lipids and nitrates are confined to more intensive production systems. These practices were estimated to reduce emissions by up to 379 metric megatons of carbon dioxide (CO₂) equivalent emissions per year (MtCO₂-eq yr^?1). Two thirds of this reduction was estimated to be possible at a carbon price of 20 US dollars per metric ton of CO₂ equivalent emissions ($20 tCO₂-eq^?1). This study also provides strategic guidance as to where abatement efforts could be most cost effectively targeted. For example, improved grazing management was particularly cost effective in Latin America and Sub-Saharan Africa, while legume sowing appeared to work best in Western Europe and Latin America.     

过牧对草地生态系统服务价值的影响——以甘肃省玛曲县为例

文章以甘肃省玛曲县为例,通过对该县草地状况的分析,以玛曲县20世纪80年代草地状况作为过牧前状态,目前草地状况作为过牧后状态,探讨过牧对草地生态系统服务价值的影响,并通过对该县草地生态系统的分析,建立了过牧对草地生态系统服务价值影响评价指标体系,即食物生产、调节大气、营养物质循环与贮存、控制侵蚀、涵养水源、环境污染净化六大功能。最后运用生态经济学方法对过牧造成的经济损失进行了初步估算。结果表明,玛曲县由于过牧造成的直接和间接经济损失分别为:食物生产1.50×108元,调节大气1.04×109元,营养物质循环与贮存0.99×108元,控制侵蚀1.02×107元,涵养水源3.94×108元,环境污染净化2.9×107元,总经济损失达到1.72×109元,其中,间接经济损失占91.3%。     

广东省人为源氨排放清单及减排潜力研究

根据各类氨排放源活动水平数据,采用排放因子法,建立了2010年广东省人为源氨排放清单,在分析其排放特征的基础上探讨了氨的减排潜力.结果表明:2010年广东省人为源氨排放量为582.9 kt,畜禽和氮肥施用是排放贡献最大的人为源,分别占总排放量的44.2%和40.4%;茂名、湛江和肇庆依次是排放量最大的3个城市,共占广东省总排放量33.0%;在畜禽源中,肉猪排放量最大,占畜禽源排放总量44.4%,其次是肉鸡、母猪和黄牛,分别占16.0%、15.2%和6.5%;畜禽在畜舍、储存管理、农田施肥和放牧4个养殖阶段的氨排放量不同;控制农业源对NH3的减排起关键性作用,茂名、湛江和肇庆是广东省重点控制的3个城市,肉猪、母猪、肉鸡、黄牛和氮肥施用则为重点控制源,主要控制措施包括低氮饲料喂养、畜舍改造、粪便密封、粪肥注施、延长放牧时间和使用尿素替代物.     

The influence of grassland management on ground beetles (Carabidae, Coleoptera) in Swiss montane meadows

Effects of grassland management type and intensity on carabid species richness, number of individuals and species composition were studied in the Swiss Prealps. Carabids were censused in 2001 and 2002 in 21 mown and 20 grazed meadows by means of pitfall traps.Mean species richness was significantly higher in mown plots than in grazed plots and species composition was significantly different between these two management types. Additionally, different species characteristic for mown and grazed plots were found. These results suggest that mown meadows and grazed meadows represent two habitat types for carabid beetles.Within both habitats, management intensity was quantified by fertilizing intensity, the number of cuts, cattle density and/or grazing intensity. The relationship between management intensity and the number of individuals and species was positive. Higher fertilizing intensity was the most important factor for higher species richness and had a significant influence on species composition in both habitats. Other variables positively related to the number of individuals, were the number of cuts in mown meadows and grazing intensity and altitude in grazed meadows. Additionally to fertilizing intensity, cattle density was positively related to the number of species in grazed meadows. These results illustrate that in the extensive management systems found in the Swiss Alps and Prealps, even intensively managed meadows can sustain high carabid diversity and abundance.     

Vegetation dynamics in abandoned crop fields on a Mediterranean island: Development of succession model and estimation of disturbance thresholds

This case study on the Sifnos island, Greece, assesses the main factors controlling vegetation succession following crop abandonment and describes the vegetation dynamics of maquis and phrygana formations in relation to alternative theories of secondary succession. Field survey data were collected and analysed at community as well as species level. The results show that vegetation succession on abandoned crop fields is determined by the combined effects of grazing intensity, soil and geological characteristics and time. The analysis determines the quantitative grazing thresholds that modify the successional pathway. Light grazing leads to dominance by maquis vegetation while overgrazing leads to phryganic vegetation. The proposed model shows that vegetation succession following crop abandonment is a complex multi-factor process where the final or the stable stage of the process is not predefined but depends on the factors affecting succession. An example of the use of succession models and disturbance thresholds as a policy assessment tool is presented by evaluating the likely vegetation impacts of the recent reform of the Common Agricultural Policy on Sifnos island over a 20–30-year time horizon.     

树脂吸附法处理黄连素模拟废水

利用树脂吸附法对黄连素模拟废水进行了试验研究,对5种大孔吸附树脂进行初步筛选,从中优选出最佳吸附树脂(大孔树脂H103)。考察了pH和树脂投加量对吸附效果的影响,绘制了动力学曲线和吸附等温线。结果表明:在黄连素浓度为1 000 mg/L,最佳初始pH为7.0的条件下,树脂最佳投加量为3.0 g。在最佳pH条件下,吸附等温线可用Freundlich等温吸附方程描述。     

Greenhouse gas abatement strategies for animal husbandry

Agriculture contributes significantly to the anthropogenic emissions of non-CO₂ greenhouse gases methane and nitrous oxide. In this paper, a review is presented of the agriculture related sources of methane and nitrous oxide, and of the main strategies for mitigation. The rumen is the most important source of methane production, especially in cattle husbandry. Less, but still substantial, amounts of methane are produced from cattle manures. In pig and poultry husbandry, most methane originates from manures. The main sources of nitrous oxide are: nitrogen fertilisers, land applied animal manure, and urine deposited by grazing animals. Most effective mitigation strategies for methane comprise a source approach, i.e. changing animals’ diets towards greater efficiencies. Methane emissions, however, can also be effectively reduced by optimal use of the gas produced from manures, e.g. for energy production. Frequent and complete manure removal from animal housing, combined with on-farm biogas production is an example of an integrated on-farm solution. Reduced fertiliser nitrogen input, optimal fertiliser form, adding nitrification inhibitors, land drainage management, and reduced land compaction by restricted grazing are the best ways to mitigate nitrous oxide emissions from farm land, whereas, management of bedding material and solid manure reduce nitrous oxide emissions from housing and storage. Other than for methane, mitigation measures for nitrous oxide interact with other important environmental issues, like reduction of nitrate leaching and ammonia emission. Mitigation strategies for reduction of the greenhouse gases should also minimize pollution swapping.