Estimation of nitrogen and phosphorus flows in livestock production in Dianchi Lake basin,China

We assessed the nitrogen (N) and phosphorus (P) flows in intensified livestock production systems by investigating nutrient budgets and cycling in the basin of Dianchi Lake, one of the most eutrophic lakes in China. We conducted field surveys based on feed samplings and interviews of livestock farmers. The N and P in local and external feeds, animal body retentions, animal products and excretions were calculated at the individual level for dairy cattle, fattening pigs, breeding sows, broilers and laying hens. The N and P flows in the total livestock production system in the area were estimated by multiplying the individual N and P budgets by the number of animals. For the dairy and fattening pig productions, N and P supplied from local crops or by‐products accounted for large parts of the inputs. For the other livestock categories, most of the N and P inputs depended on external resources. The N and P outputs through animal manure into the cropland were 287 and 66 kg/ha/year, respectively, which were higher than the N and P inputs into the livestock production systems from the cropland. The N and P loads from manure should be reduced for the establishment of sustainable agricultural production systems.     

Assimilation Versus Accumulation of Macro- and Micronutrients in Soils: Relations to Livestock and Poultry Feeding Operations

Nutrient management is an integral part of profitable agrisystems, but in some areas of the United States, continued applications of fertilizer and manure nutrients in excess of crop requirements have led to a buildup of nutrient concentrations that are of environmental concern. Proper use of nutrients in livestock manures is becoming more critical for sustainability of concentrated animal feeding operations (CAFO) because new environmental regulations require that nutrients be properly applied and managed. Losses of nutrients, such as N and P can be reduced by refining the rations fed, increasing nutrient retention by livestock, moving manures from areas of surplus to deficiency, finding alternative uses for manure, using cropping and haying systems that remove excess nutrients, and using conservation practices, such as limited tillage, buffer strips, and cover crops to limit runoff and leaching. Whole farm nutrient balances are useful for educating producers about quantities of nutrients being managed and the flow of nutrients, but they can also be misleading because of spatial factors, such as uneven nutrient application that introduce environmental risks that may not be noted with a whole-farm nutrient balance. Manure utilization plans also need to deal with nutrients that potentially leave the field or production area in route to sensitive ecosystems.     

基于土地承载潜力的养殖总量控制研究:以江苏省东海县为例

为确定江苏省连云港市东海县畜禽适宜养殖量,本研究基于氮平衡分析畜禽土地承载力。结果表明:2015年,东海县全年农作物氮养分需求量、猪粪氮当量、化肥施用量(以氮计)分别为4.39万、2.52万、4.44万t,可见东海县具有足够的畜禽粪污消纳能力和较大的降低化肥施用潜力。以氮养分计,东海县畜禽养殖承载潜力为199万头猪当量,还有77万头猪当量的盈余。不同乡镇存在较大差异,山左口、双店、石梁河等3个乡镇稍有超载,应适当调减养殖量;牛山街道和石榴街道2个乡镇靠近城区,禁养区、限养区面积较大,应逐步减少养殖量;黄川、桃林、安峰、白塔埠等4个乡镇尚有一定的发展空间,可维持现有养殖量或适当扩大养殖量;其余乡镇发展潜力较大,东海县畜禽养殖应逐步由养殖密集区域向这些乡镇转移。     

Livestock nutrient management concerns: regulatory and legislative overview

A greater focus on manure nutrient disposition from concentrated animal-feeding operations has developed from environmentalists, concerned citizens, and regulatory agencies. The establishment and enforcement of manure nutrient regulations will alter the future of livestock production. Proposed legislation and strategies may provide a false sense of security regarding environmental preservation or restoration and may impose monitoring and record keeping on the livestock operators. Existing regulations and proposed regulations and strategies are presented. Implications of legislation and proposed strategies, policies, and regulations are discussed. Livestock operations will need to comply with regulations to remain in business and to minimize environmental liability.     

Nutrient balances as indicators for sustainability of broiler production systems

1. Flock balances of nitrogen, phosphorus, zinc and copper (N, P, Zn, Cu) were calculated in order to evaluate environmental effects of three different broiler production systems (intensive indoor, free range and organic). 2. Nutrient gain in birds per unit nutrient intake (retention) in intensive indoor production was higher than in free range and organic production. 3. Nutrient surplus relative to nutrient retention was higher in organic production than in free range and intensive indoor production. 4. The main reasons for differences in nutrient efficiency between intensive indoor, free range and organic production were duration of growth period, strain of broilers and feeding strategy. 5. The calculation of whole farm indicators (livestock density, N and P excretions per hectare of farmland) demonstrates how defining system boundaries affects the outcome of an evaluation: organic farms had the smallest livestock densities and the lowest N and P excretions per hectare of farmland. 6. In the efforts to reach a more holistic evaluation of agricultural production systems, the definition of adequate system boundaries must be discussed. In addition to nutrient balances, further indicators of sustainability, such as human and ecological toxicity, should be considered.     

Societal expectations of livestock farming in relation to environmental effects in Europe

The potential environmental effects of livestock farming are mainly associated with intensification of poultry, pig and dairy cow production systems. The major impacts are mainly caused by housing of livestock, which can lead to air and water pollution associated with nitrogen and phosphorus emissions and losses from manure. European countries regulate the potential for these types of pollution through a number of mechanisms, which have received wide public acceptance. In grazing systems, nitrogen pollution, associated with the use of nitrogen fertilizer, is also the subject of legislation. Perhaps because of this regulatory approach, surveys of the public have found that human food quality and animal welfare are more important issues than effects on air and water quality when considering livestock systems.Variation in stocking rates of grazing ruminants can change the structure and composition of pastures with potential impacts on biodiversity and the production of methane, a greenhouse gas. In European countries, maximum stocking rates have been set to reduce these impacts. Surveys of the European public have suggested that they are willing to pay for the mitigation of these environmental effects but that they also value strongly the cultural component of grazed livestock systems. There are few underlying concepts about how society views the environmental impacts of livestock systems. These are used to conclude that current attitudes are likely to prevail in the next decade.     

Pollution due to nutrient losses and its control in European animal production

Differences in soil, climate and socioeconomic conditions cause animal production to vary widely between European regions, notably in animal density and percentage landless farming. They have in common that animal products result from the cycling and redistribution of nutrients through soil, air, plants, animals and manure, with energy from photosynthesis or from the input of fossil energy as driving force. Nature of nutrients and rates of their conversion vary between and within cycle components, and consequently imbalances occur, causing undesired nutrient losses to or extractions from soil, water and air. Nutrients causing environmental concern are those containing excessive phosphorus (P), potassium (K) and nitrate (NO₃⁻), contaminating soil and water and those losing the greenhouse gases carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O) into the air. Successful and feasible interventions are to extensify, to reduce external inputs and to optimise. Maximum stocking density should not exceed 2.0 livestock units (LU)/ha. Reductions in external inputs of N, P and K are possible through reduction in fertiliser inputs and by reducing or applying compositional changes of dietary inputs. Optimisation at farm level includes implementing the nutritive measures mentioned above combined with an increased reproductive efficiency by lowering the number of parent animals. Animal manure should be treated as a commodity rather as a waste, with a tailor made composition to be achieved by nutrition or by fractionation. The recommended measures require legal and mental interventions, the success of which will largely depend on the quality of legislation and the acceptability of its implementation.     

Nitrogen, phosphorus and potassium utilization and their cycling in a beef-forage production system

The objective of this study was to quantify nitrogen (N), phosphorus (P) and potassium (K) utilization and their cycling in a beef-forage production system. A survey was conducted at the Kyoto University experimental farm in Kyoto Prefecture, Japan, and included 9.5 ha of meadow and about 160 head of beef cattle. Forages cultivated on the meadow were ensiled and offered to breeding cows. The whole farm was regarded as a beef-forage production system. The system consisted of three components: animals, manure and soil/crop. Nutrient inputs, flows through the soil-plant-animal pathway and outputs were quantified for 2 periods for the whole farm. Nutrient utilization was evaluated by nutrient balances, utilization efficiencies (ratio of nutrient export to nutrient input) and cycling index. The average nutrient balances of N, P and K for the whole farm (kg/year/ha) were 435.7, 136.3, and 262.8, and the average nutrient utilization efficiencies were 0.08, 0.06, and 0.01, respectively. The characteristics of nutrient balances and utilization efficiencies for each component differed among the nutrients. The average cycling indices for N, P and K were 0.19, 0.17 and 0.49, respectively. This study illustrates the importance of internal nutrient cycling for improving nutrient utilization in beef production systems.     

动物饲料国际贸易、养殖密度与环境氮磷平衡的关系

粮食和饲料的国际贸易促进了许多国家农业生产系统的专业化和集约化。专业化动物养殖越来越多地依赖进口大豆和玉米,虽然提高了动物生产力,但也促使作物和动物生产系统在空间上的分离。本文综述了几十年来全球范围内大豆和玉米的贸易变化,并将其与养殖密度和整个食品系统中营养平衡的变化联系起来。这一变化与不同的营养管理条例的差异和动物饲养密度的空间变化有关。深入解析这些变化有助于理解动物饲料国际贸易、养殖密度与氮磷平衡之间的复杂关系。     

Recycling of livestock manure in a whole-farm perspective

Intensification increases the environmental impact of livestock production systems. Efforts to recycle nutrients in livestock manure for crop production will effectively reduce several pollution problems, although general solutions are difficult to devise in view of the diversity in production systems, management strategies and legislation between countries and regions. This paper argues that a whole-farm perspective taking side-effects and on-farm interactions into account is needed to determine the cost-effectiveness of strategies to mitigate pollution from livestock manure management. Animal feeding plays a key role in the control of nutrient flows on livestock farms, since the diet affects the composition of excreta. There is a great potential for manipulating manure composition by diet manipulations. Manure is a significant source of heavy metals in soil, and in Europe the permitted levels of Cu and Zn in livestock diets have been lowered to reduce their environmental impact. A variety of environmental technologies are being developed for treatment of manure, many of which have a significant potential for reducing nutrient losses. Internationally agreed and enforced regulations that link pollution control with the adoption of best available technologies could provide the demand that is needed to drive research and development. In the past, policy-makers have typically focused on individual environmental problems. It is essential, however, that the efforts to close nutrient cycles on the farm are accompanied by a corresponding reduction in total inputs, otherwise losses after field application will increase. Integrated assessment tools are needed which can evaluate all internal flows of nutrients, imports and exports, energy use, hygienic risks and contaminants, as well as costs, at the farm-scale and beyond. It is important to consider pollution control strategies for a farm in the framework of local and regional pollution control planning.     

区域畜禽养殖潜力评价方法与应用研究——基于种养平衡视角分析

种养平衡是区域畜牧业发展的重要趋势之一,测算区域畜禽养殖潜力将成为各地区畜牧业发展的重要工作。本文基于种养平衡理念,认为区域畜禽养殖潜力是植物粪肥养分需要量扣除掉畜禽粪肥养分生产量后的数值空间,并利用此方法测算了吉林省松原市5个县市的畜禽养殖潜力。结果表明:按照粪肥提供氮素占总氮素15%的比例来计算,松原市可容纳的畜禽粪污总量约为3.80万t,目前的养殖数量已经占用2.88万t,还有0.92万t的养殖空间,但个别县市畜禽养殖潜力已经接近极限。提高农户粪肥施用比例,区域畜禽养殖潜力将有很大的增加空间,如果减少猪而增加其他畜禽养殖也能提供养殖空间。北方区域畜禽养殖规模增长必须充分考虑种养平衡的关系,畜禽养殖潜力不大的区域不宜盲目增加养殖规模。     

Investigating the potential for genetic improvement of nitrogen and phosphorus efficiency in a Swiss large white pig population using chemical analysis

Pig production contributes to environmental pollution through excretion of phosphorus and nitrogenous compounds. European pig production requires annual imports of currently 36 million tons of soya bean, because domestic plant protein sources often do not meet the required protein quality. Most of the mineral phosphate sources are also imported. It is therefore desirable to improve nutrient deposition efficiency through selective breeding, that is to realise similar growth rates and carcass compositions as currently achieved but with a lower intake of dietary crude protein or phosphate. For a preliminary evaluation of the potential of selecting for increased nutrient deposition efficiency, we estimated genetic parameters for nitrogen and phosphorus efficiencies in a Swiss Large White pig population including 294 individuals. Nutrient efficiency phenotypes were obtained from wet-chemistry analyses of pigs of various live weights. Heritability of nitrogen efficiency was estimated at 41%. Heritability of phosphorus efficiency was very low (0.3%), but positive genetic correlations with nitrogen efficiency suggest that breeding for nitrogen efficiency would positively affect phosphorus efficiency. Further studies are needed to improve the quality of estimates and to obtain accurate high-throughput measures of nutrient efficiency to be implemented on farms.     

Nitrogen utilisation efficiency in small-scale dairy systems in the highlands of Central Mexico

Nitrogen (N) plays an important role in small-scale dairy systems, both in production costs and as an indicator of environmental impact. The objective of this study was to quantify nitrogen inputs and outputs to identify areas for improvement in nitrogen utilisation efficiency (NUE). Evaluation was in 12 small-scale dairy farms with different feeding strategies. Six followed the traditional cut and carry of irrigated temperate pastures (CUT), and six have implemented grazing of pastures (GRZ), quantifying N inputs and outputs from May 2016 to April 2017. Data were analysed by ANOVA following a split-plot model with season (rainy or dry) as main plots and feeding strategy (CUT or GRZ) as split-plots, with results in kilograms N per hectare and kilograms N per cow. There were differences (P < 0.05) between seasons and strategies in N inputs from purchased N fertilisers and purchased feeds as concentrates and roughages, showing different N inputs and outputs whether in CUT or GRZ strategies. There were also significant interactions between seasons and strategies as in the sale of animals, where GRZ sell throughout the year, while CUT sell at the beginning of the dry season. N balance ranged from 33.9 to 183.0 kg N/ha, and 37.8 to 111.0 as kilograms N per cow with an interaction (P < 0.05) between season and strategies. There was a larger N surplus in GRZ during the rainy season from fertiliser inputs, which reduced N utilisation efficiency (NUE). Mean NUE in kilograms N per hectare and kilograms N per cow was 19%, with the higher efficiency for GRZ in the dry season. Farms with the best NUE had lower use of fertilisers and purchased feeds.

     

The Effects of Urbanization on the Siting and Expansion of Livestock Facilities in Illinois Under Proposed Legislation: A Spatial Analysis

Across the country, setback restrictions that require livestock facilities to be located away from neighboring residences and populated areas are making the siting or expansion of operations a growing challenge for livestock producers. In this study, Geographic Information Systems (GIS) technology was utilized to examine the impact of increasingly restrictive legislation on the availability of land for the siting or expansion of confined livestock operations. Georeferenced data from two southern Illinois counties were analyzed to quantify the effects of a proposed amendment to the Illinois Livestock Management Facilities Act that would increase the setback distances required between confined livestock operations and populated areas. The results of this study demonstrate that increases in setback distances can greatly reduce the availability of rural land for the siting of livestock facilities, even in rural counties with low population densities. In Franklin County, Illinois, a proposed 3.2-km setback distance would remove 70% of rural land from availability for livestock facilities siting. This loss would be experienced even though only 4.2% of the county is urbanized. Results also suggest that the land-use impacts from siting legislation may be reduced when urban development is clustered rather than scattered across the landscape.     

Exploring the Role of Management in the Coproduction of Ecosystem Services from Spanish Wooded Rangelands

The wood pastures or hardwood rangelands of the southwestern Iberian Peninsula are complex social-ecological systems created from the long-term interaction of society and the landscape. Dehesa, oak woodlands managed for grazing, cropping, and other forms of production, is the most common rangeland system and one of the most distinctive landscapes. Traditionally characterized by multifunctional low-intensity management that enhances a wide range of ecosystem services, current management has shifted from the traditional toward more intensified models. This paper assesses the coproduction of ecosystem services on dehesa properties by exploring the relationship between biophysical and sociocultural factors and dehesa management practices. Based on 42 surveys we analyze 16 quantitative indicators using multivariate techniques. The results indicate that there are four main dehesa types as defined by their characteristics and management: large heterogeneous operations with diverse products; small and homogeneous operations focused on a reduced number of products; medium-large properties focused on crop production; and midsized properties with easy public access. Management is the result of the dynamics of interacting biophysical and sociocultural factors that influence manager priorities and investments. Management decisions group around the degree of multifunctionality of the operation, the relative importance of crop production, the degree of grazing pressure in the system, and how restrictive public access policy is. We find that in the study area, interactions between all the previously mentioned elements covary consistently, generating bundles of ecosystem services associated with each of three management models based on the intensity of management.     

发酵床垫料无害化处理技术研究

通过对发酵床养猪后发酵床垫料的无害化堆肥技术研究,对垫料堆肥过程中堆肥温度、pH值、电导率、总养分（有机质、全氮、全磷、全钾）、有效养分（有效磷、速效钾）、堆肥腐熟度（种子发芽指数）等指标进行监测并分析。结果表明：发酵床养猪系统中产生的有机垫料经过堆肥化处理后的产物达到了有机肥料标准,是一种优质的有机肥;不仅解决了畜禽...     

Diverse Management Strategies Produce Similar Ecological Outcomes on Ranches in Western Great Plains: Social-Ecological Assessment

Experiments investigating grazing systems have often excluded ranch-scale decision making, which has limited our understanding of the processes and consequences of adaptive management. We conducted interviews and vegetation monitoring on 17 ranches in eastern Colorado and eastern Wyoming to investigate rancher decision-making processes and the associated ecological consequences. Management variables investigated were grazing strategy, grazing intensity, planning style, and operation type. Ecological attributes included the relative abundance of plant functional groups and categories of ground cover. We examined the environmental and management correlates of plant species and functional group composition using nonmetric multidimensional scaling and linear mixed models. After accounting for environmental variation across the study region, species composition did not differ between grazing management strategy and planning style. Operation type was significantly correlated with plant community composition. Integrated cow-calf plus yearling operations had greater annual and less key perennial cool-season grass species cover relative to cow-calf − only operations. Integrated cow-calf plus yearling ranches were able to more rapidly restock following drought compared with cow-calf operations. Differences in types of livestock operations contributed to variability in plant species composition across the landscape that may support diverse native faunal species in these rangeland ecosystems. Three broad themes emerged from the interviews: 1) long-term goals, 2) flexibility, and 3) adaptive learning. Stocking-rate decisions appear to be slow, path-dependent choices that are shaped by broader social, economic, and political dynamics. Ranchers described having greater flexibility in altering grazing strategies than ranch-level, long-term, annual stocking rates. These results reflect the complexity of the social-ecological systems ranchers navigate in their adaptive decision-making processes. Ranch decision-making process diversity within these environments precludes development of a single “best” strategy to manage livestock grazing.     

The wild horse controversy

Differing viewpoints regarding wild (feral) horse management have resulted in majorcontroversy for public land management. While the livestock industry has not advocated the eradication of wild horses, much of the publicity on the issue has given this misleading impression. The livestock industry has advocated wild horse management. Wild horse herds have, in some cases, presented major management conflicts for ranchers when they have been allowed to multiply to uncontrolled numbers. In many areas, wild horse management has been secondary in priority to completion of environmental impact statements. During this interim period, wild horse herds have gone without management. Livestock numbers have been regulated by management agencies in accordance with forage production. Wild horses also must be managed within the carrying capacity of the rangeland. Management plans developed and implemented jointly by all interested factions present the best viable solution to the wild horse controversy.     

植物叶片氮磷养分重吸收规律及其调控机制研究进展

植物养分重吸收是植物组织或器官在衰老脱落前将部分养分(主要如氮、磷)转移到其他成活组织的过程,能延长养分在植物体内的存留时间,提高养分利用效率,减少植物对土壤养分的依赖,是植物适应环境的重要策略之一。本研究综述了土壤水分和肥力、光照、温度等环境因子和寿命、个体发育等遗传特性对植物叶片氮磷养分重吸收的影响。不同生活型或功能型的叶片养分重吸收不同;施肥会改变土壤速效养分的含量和比例,从而调控叶片养分重吸收;土壤水分通过调节土壤养分有效性而影响叶片养分重吸收;植物在生长过程中,不同时期对养分的需求有所差异,对养分的敏感程度和吸收能力也各不相同,从而表现出不同叶片养分重吸收特征;除了叶片之外,植物的其他组织器官(如,细茎、树木的芯材和能够储存养分的根)也可以进行养分重吸收。因此,植物叶片养分重吸收易受多种因素的影响,不同物种的重吸收能力存在差异,同一物种在不同时、空及相关因素变化下的重吸收特性也不同。深入研究植物养分重吸收规律和调控机制有助于进一步揭示植物的环境适应性,能为提高水肥管理水平,权衡生产力和适应性,实现系统生产和生态可持续发展提供理论依据。     

不同环境温度下沼液养分在土壤中的淋失模拟研究

沼液因其养分利用率高,被广泛应用于农业生产中,而环境温度可通过影响土壤的物理化学性质,影响沼液养分的淋溶损失。试验采用土柱模拟法,研究了不同环境温度对土壤沼液养分淋溶的影响,旨在揭示不同季节土壤养分淋溶可能存在的差异,为生产中合理施用沼液提供理论依据。土柱规格为内径7.5 cm、高20 cm的聚氯乙烯(PVC)管,按每公顷施入0,130和260 kg N,设置每土柱沼液灌溉总量为0,200和400 mL。按当地年平均降雨量的70%计算实际浇灌量为1500 mL,分5次每隔6 d模拟不同降雨次数进行浇灌。沼液浇灌前用清水补足不足部分并混匀。土柱放置于20和30℃的温室培养,每次淋溶后收集土壤淋溶液,测定其全氮、硝态氮、铵态氮、全钾、全磷、速效磷和电导率。结果表明,施用沼液后淋溶液中氮、磷、钾淋失量较清水对照显著增大,其中40 mL沼液水平下,全氮含量平均增加73%,全磷含量增加880%,全钾含量增加388%,且随着沼液用量的增加淋溶液中的养分浓度呈增加趋势。环境温度的提高增加了沼液养分在土壤中的淋溶损失,30℃时淋溶液中的硝态氮、全氮、全钾、全磷、速效磷含量及电导率整体高于20℃,其中全氮平均提高14.68%,全磷平均提高33.59%,全钾平均提高24.08%。整体而言,30℃下沼液养分较20℃时更易发生淋失。因此,在农业生产中,应适当减少夏季高温时的沼液施用次数,增加春秋季节施用次数,但沼液用量不要超过130 kg N/hm²,防止沼液养分大量流失,污染周边环境。