翻译专业-开题报告新(1)

大连大学

本科毕业论文(设计)开题报告

论文题目：《关于生物能源原料生产的潜在

热带多年生牧草种植情景的碳预

算》翻译实践报告

学院：英语学院

专业、班级：翻译152

学生姓名：刘奎

指导教师（职称）：郑希彬

2018年 11 月 18 日填

毕业论文（设计）开题报告要求

开题报告既是规范本科生毕业论文工作的重要环节，又是完成高质量毕业论文（设计）的有效保证。为了使这项工作规范化和制度化，特制定本要求。

一、选题依据

1.论文（设计）题目及研究领域；

2.论文（设计）工作的理论意义和应用价值；

二、论文（设计）研究的内容

1.重点解决的问题；

2.拟开展研究的几个主要方面（论文写作大纲或设计思路）；

3.本论文（设计）预期取得的成果。

三、论文（设计）工作安排

1.拟采用的主要研究方法（技术路线或设计参数）；

2.论文（设计）进度计划。

四、文献查阅及文献综述

学生应根据所在学院及指导教师的要求阅读一定量的文献资料，并在此基础上通过分析、研究、综合，形成文献综述。必要时应在调研、实验或实习的基础上递交相关的报告。综述或报告作为开题报告的一部分附在后面，要求思路清晰，文理通顺，较全面地反映出本课题的研究背景或前期工作基础。

五、其他要求

1.开题报告应在毕业论文（设计）工作开始后的前四周内完成；

2.开题报告必须经学院教学指导委员会审查通过；

3.开题报告不合格或没有做开题报告的学生，须重做或补做合格后，方能继续论文（设计）工作，否则不允许参加答辩；

4.开题报告通过后，原则上不允许更换论文题目或指导教师；

5.开题报告的内容，要求打印并装订成册（部分专业可根据需要手写在统一纸张上，但封面需按统一格式打印）。

附：1000字原文及译文

翻译原文

Carbon budgets of potential tropical perennial grass cropping scenarios for bioenergy feedstock production Abstract

Background: The environmental costs of fossil fuel consumption are globally recognized, opening many pathways for the development of regional portfolio solutions for sustainable replacement fuel and energy options. The purpose of this study was to create a baseline carbon (C) budget of a conventionally managed sugarcane (Saccharum officinarum) production system on Maui, Hawaii, and compare it to three different future energy cropping scenarios: (1) conventional sugarcane with a 50% deficit irrigation (sugarcane 50%), (2) ratoon harvested napiergrass (Pennisetum purpureum Schumach.) with 100% irrigation (napier 100%), and (3) ratoon harvested napiergrass with a 50% deficit irrigation (napier 50%).

Results: The differences among cropping scenarios for the fossil fuel-based emissions associated with agricultural inputs and field operations were small compared to the differences associated with pre-harvest burn emissions and soil C stock under ratoon harvest and zero-tillage management. Burn emissions were nearly 2000 kg Ceq ha?1 year?1 in the conventional sugarcane; whereas soil C gains were approximately 4500 kg Ceq ha?1 year?1 in the surface layer of the soil profile for napiergrass. Further, gains in deep soil profile C were nearly three times greater than in the surface layer. Therefore, net global warming potential was greatest for conventional sugarcane and least for napier 50% when deep profile soil C was included. Per unit of biomass yield, the most greenhouse gas (GHG) intensive scenario was sugarcane 50% with a GHG Index (GHGI, positive values imply a climate impact, so a more negative value is preferable for climate change mitigation) of 0.11 and the least intensive was napiergrass 50% when a deep soil profile was included (GHGI = ? 0.77).

Conclusion: Future scenarios for energy or fuel production on former sugarcane land across the Pacific Basin or other volcanic islands should concentrate on ratoon-harvested crops that maintain yields under zero-tillage management for long intervals between kill harvest and reduce costs of field operations and agricultural input requirements. For napiergrass on Maui and elsewhere, deficit irrigation maximized climate change mitigation of the system and reduced water use should be part of planning a sustainable, diversified agricultural landscape.

Keywords: Global warming potential, Greenhouse gas index, Napiergrass, Ratoon crop, Sugarcane

Interest in the production of renewable biofuel from lignocellulosic crops is gaining global recognition as a leading alternative energy scenario in future fuel markets. Te negative environmental costs associated with fossil fuel consumption are being recognized and accounted on an international level due primarily to the adoption of the Kyoto Protocol in 2005. Since then, the development of alternative fuel sources has been a major concern for

nations like the United States that rely heavily on imported fossil fuel. Test pressures can result in a shift from the conventional food-crop agriculture to bioenergy systems in the United States and production of renewable biomass sources has been accelerated in recent years due to government regulations. More specifically, regulations such as the Energy Independence and Security Act (EISA) of 2007 have mandated that fossil fuel sources must be mixed with at least 36 billion gallons of renew-able fuel by the year 2022, meeting approximately 25% of liquid-based fuel needs by 2050. In support of national policy, Hawaii is under similar pressure resulting from the 2008 Hawaii Clean Energy Initiative (HCEI), which mandates a local, efficient, and renewable source of fuel be developed for Hawaii by the year 2030. The HCEI specifically requires that 40% of the states fossil energy be replaced with “locally generated renewable sources” over the next 17 years. These increasing fuel demands may place additional stress on already exploited agricultural lands resulting in land intensification and conversion if not managed conservatively. Agricultural intensification can negatively impact soil carbon (C) storage, increase greenhouse gas (GHG) emissions, and offset the overall ecosystem C balance if managed incorrectly. The energy sector en masse converted annual croplands into perennial biomass systems over the past decade, which was thought to provide GHG mitigation potential through an improvement in soil quality and a reduction in nutrient amendments. In recent years, however, conflicting results about the mitigation potential of these systems raised questions about the true system-level GHG offset . Shortages in the world’s productive croplands and the impending scarcity of water made worse by climate change lead to additional uncertainty in the sustainability of increasing the world’s biofuel acreage. Due to the wide range of conflicting viewpoints on the bioenergy issue, documentation of local and regional data sets that quantify these uncertainties are of the utmost importance.

The total GHG balance of biofuel production is difficult to capture because of the large variation in cropping practices, land management, and equipment usage across these agricultural systems. Additionally, many recent studies focused on single-species scenarios that are specific to Brazilian ethanol production and are not entirely applicable to addressing regional issues outside of their study areas. Although these studies can be a powerful tool to advance the global implications of bioenergy production under a large agricultural infrastructure, additional small-scale studies are required to assess the trade of between these systems and provide alternative management options on a local scale. To do this, a GHG balance needs to be created based on site-specific data that incorporates the energy inputs (fossil and non-fossil fuel) required to establish and maintain a bioenergy cropping system. For the majority of these GHG assessments, fossil energy inputs are converted using emission factors to carbon dioxide equivalents (CO2eq). Referred to as a global warming potential (GWP), these CO2eq are comparable on an international scale. This kind of GHG accounting allows for a direct comparison between the GHGs emitted by agricultural operations and the GHGs saved by the production of a renewable fuel sources. For the purposes of GHG accounting, all emissions were converted into a similar C equivalent (Ceq) in order to make a direct comparison with the amount of soil C stored under each cropping practice. This C budget related the GWP of each of these systems to their crop production, which allows for estimation of the overall GHG intensity (GHGI) of a production system .

To date, there has been no known C budget specific to the agricultural operations in Hawaii,

which makes comparing future cropping scenarios against current practices impossible. With over 11,000 ha?1 of Maui being state designated and protected agricultural land, the future sustainability of this region may lie with the adoption of an energy crop scenario that is able to displace fossil fuel based GHG emissions. The purpose of this study was to create a baseline C budget for a conventionally managed sugarcane production system on (100% irrigation) Maui and compare it to three different future energy cropping scenarios: [1] conventional sugarcane with a 50% deficit irrigation (sugarcane 50%), [2] ratoon harvested napiergrass with 100% irrigation (napier 100%), and [3] ratoon harvested napiergrass with a 50% deficit irrigation (napier 50%). This comparison will help identify, in terms of their agricultural C budgets, the best-case scenario for future biofuel production in Hawaii and other Pacific Basin island nations.

Methods

Site description and experimental design

The field experiment was conducted in central Maui, Hawaii (20.89°N, 156.41°W) on Hawaiian Commercial and Sugar Company (HC&S) land. At the time of the study, HC&S was the only remaining sugarcane plantation in Hawaii. The experimental plots were within a highly weathered, very-fine, kaolinitic, isohyperthermic Typic Eutrotorrox of the Molokai series in field, which is approximately 100 meters above sea level and has a total commercial area of 72 ha. The soil is well drained, rocky, and has deep, well-defined horizons below the plow layer . Soil pH was 7.97, and C concentration was 1.37% on average in the top 40 cm with a mean bulk density of 1.51 g cm3 as assessed by the baseline soil collection in 2011. During the trial period, average annual air temperature was 23.4℃and annual precipitation was 241 mm, which are consistent with long-term averages for the area.

The experiment was a strip-plot, group-balanced design with two factors, irrigation and species with three replicates (blocks) (please see [16] for additional details). Irrigation was applied at the standard plantation rate (100%), and two deficit irrigation rates (75% and 50% of plantation standard). The original trial included four species, sugarcane (Saccharum officinarum), energycane (Saccharum officinarum x Saccharum spontaneum), napiergrass (Pennisetum purpureum Schumach.), and sweet sorghum (Sorghum bicolor (L.) Moench). For this study, two crops (sugarcane and napiergrass) were evaluated at two irrigation levels (50% and 100%). On June 26, 2011 the field plots were established in a recently harvested sugarcane field that had been in a cane-on-cane rotation for over 100 years. The sugarcane plots were planted with seed cane from an adjacent field within the HC&S plantation and napiergrass seed crop was supplied from a harvested population at the University of Hawaii’s research station in Waimanalo, Oahu.

Deficit irrigation treatments were applied to the field from November 13, 2011 depending on water availability across the plantation and were controlled with automated timers. From November 2011–October 2012, 1245 mm water ha?1 were applied to the 100% plots and 633 mm water ha?1 were applied to the 50% plots, for an actual deficit treatment of 50.8%. During the study period, the napiergrass plots were harvested every 6 months (a time interval that maximizes yield) on March 13, 2012 and September 25, 2012. The sugarcane crop was under a 2-year growth rotation and did not reach maturity during the scope of this study period and was not harvested.

Developing a baseline system for sugarcane

Sugarcane is a high-yielding, tropical C4 perennial grass of South Pacific origin. Tropical sugarcane biomass yields are up to 40 Mg dry wt ha?1 year?1 in Hawaii and 26 Mg dry wt ha?1 year?1 in Brazil. The species supports a drought resistant, robust root system that can improve soil structure and accumulate C on marginal lands.However, Hawaiian sugarcane has been grown on a 2- year crop cycle, reaching maturity after 24 months and then harvested after a low intensity burn followed by deep tillage and mechanized planting. Commercial sugarcane production existed on Maui for over 125 years. However, in January 2016 HC&S, the last remaining large-scale sugar producer, announced a wholesale transition on their 14,000 ha plantation to diversified agriculture including perennial grasses for forage, pasture, and bioenergy feedstock.

The development of a C budget or GHG analysis includes a detailed accounting of the agricultural inputs required to produce a specific crop. This includes quantifying the fossil fuel and non-fossil fuel based emissions. Fossil emissions are considered emissions resulting from fuel use during field preparation, planting, application of agrochemicals, harvesting, and maintenance. Non-fossil emissions are considered biogenic GHG emissions that consider the production of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) as a result of the production system and are primarily a result of preharvest burn operations, soil GHG exchange, and residue management. This baseline system will be referred to as the sugarcane 100% scenario for future comparisons.

Fossil emissions from fuel consumption and agricultural inputs

Field operations

Field operations (i.e., field preparation, harvest, fabrication and maintenance, seed propagation, and irrigation) often are considered to be hidden sources of emissions because of their indirect contribution to GHG flux. These emissions are caused by the burning of fossil fuel during equipment operation and accounting can be challenging partly because of large variation in the descriptive energy units. A standard unit of kg Ceq was used to assess the contribution of field operations to the total C budget. Emissions factors (EF) were used to convert the fuel use requirements of each operation to Ceq. The EFs used in this analysis represent a synthesis of the best-available and current values found in the literature. Specific information pertaining to type of equipment and usage has been obtained from personal communication with plantation staff.

When EFs found in the literature were inadequate to describe the operation on Maui, they were generated independently to best reflect current plantation practices. For example, irrigation emissions were calculated based on the average energy required to pump water across the plantation at a rate specific to Maui, 0.0057 L/ kWh (personal communication with L. Jakeway, Chemical Engineer at HC&S, 2013). Additionally, this value was adjusted to account for the total amount of water applied to a field in the 2011–2012 year to correctly reflect the amount of renewable energy used on the plantation for these operations (approximately 3:1 renewable to fossil energy ratio). An additional input to the baseline scenario was a calculation of fossil emissions related to seed cane production, which were adjusted for the weight of seed cane used in planting operations.

Agricultural inputs

Emissions from agricultural inputs (i.e., fertilizer, herbicide, and lime) are a result of the energy required to produce, transport, and distribute these items. A pre-emergence herbicide mix containing atrazine (1-chloro-3-ethylamino-5-isopropylamino-2, 4,

6-triazine), 2, 4-D (2, 4-dichlorophenoxyacetic acid), Prowl ((N-1- ethylpropyl)-3, 4-dimethyl-2, 6 dinitroben-zenamine), Rife (3, 6-dichloro-2-methoxybenzoic acid), and Velpar (3-cyclohexyl- 6-dimethylamino-1-methyl-1, 3, 5-triazine-2, 4(1H,3H)-dione) was applied once three weeks after planting. Each plot received 345 kg N ha?1 (as liquid urea: 46-0-0) applied through the drip irrigation system. The fertilizer was applied monthly once the crops were established and concluded after 10 months. The timing and rate of urea application were optimized for the 2-year sugarcane crop and were based on current HC&S plantation practices. Deficit irrigation treatments were postponed during all fertilizer application events.

Quantification of the C emissions resulting from agricultural inputs in Maui sugarcane production was based on application rate and converted to Ceq with reported EF. An EF of 0.97 was used to convert the fertilizer application rate to Ceq. Lime (CaCO3) was applied at a rate of 2569 kg ha?1 prior to field planting and converted to Ceq using an EF of 0.12. Individual emission factors were identified for each chemical used in the herbicide mix reported by HC&S. These factors were averaged and a new EF (5.64) was developed for herbicide application specific to Maui.

Non fossil emissions

Litter decomposition

Emissions from litter decomposition is a function of residue management. For example, N2O emissions can increase due to decomposition of leaf material following harvest and are greater in intact compared to burned fields. The goal on Maui sugarcane fields has been to maintain 15% of total field biomass for crop residue. Using this percentage, litter Ceq were calculated based on an average biomass production of 80.4 Mg ha?1 year?1 reported by HC&S. Emission factors for litter decomposition are based on the amount of N in crop residues following harvest.

Pre-harvest burn emissions

Conventional cultivation of sugarcane in Hawaii included a pre-harvest, low intensity burn to remove unwanted leafy material prior to harvesting. Pre-harvest burning significantly increases GHG emissions through the production of CH4 and N2O and the release of black carbon (BC) to the environment. The values used for the cropping scenarios in Maui were based on a 15% residue retention rate of total field biomass. Current IPCC values outlined in the Guide-lines for National Greenhouse Gas Inventories assessment in 2006 suggest an EF of 0.07 kg N2O per ton of dry matter burnt and an EF of 2.7 kg CH4 per ton of dry matter burnt. Black C has a GWP that is 500 times greater than CO 2 on a 100- year time horizon and it is estimated that 1 kg of BC is created for every kg of trash burnt.

Soil N2O and CH 4 emissions

Field measurement of soil fluxes in CH4, and N2O began in October of 2011 and were sampled at least monthly until October of 2012 following the GRACEnet sampling protocols , as previously reported in detail (Pawlowski et al. in review). Mid-morning measurements were collected from sealed static PVC chambers affixed to permanent collars installed in the sugarcane and napiergrass rows and inter-rows. Samples were collected by sealing each chamber and using a 10 mL polypropylene syringe and extracting 8 mL of headspace air through a septum on the styrene lid at 0, 15, 30, 45, and 60 min after chamber closure. Each gas sample was immediately injected into an evacuated Exetainer? (Labco Limited, UK) fitted with a Doubled Wadded Tefon/Silicon septa (Labco Limited,

UK) for short-term storage. Samples were analyzed using a Shimadzu GC-2014 Gas Chromatograph (Shimadzu Scientifc Instruments, Inc.), which used a fame ionization detector to measure the concentration of CH4 and CO2 after methanization, and an electrical conductivity detector for N2O analysis. Flux rates were calculated by assuming a linear change in gas concentration over time. Cumulative annual emissions of N2O and CH4 were interpolated from daily fluxes and summer over the first year and reported in terms of kg CH4 ha?1 year?1 and kg N2O ha?1 year?1. To discuss N2O and CH4 emissions in terms of a C balance, annual rates were converted into CO2eq using the IPCC 100-year horizon factors for calculating GWP. Therefore, when CO2=1 on a 100 year?1 time scale, then the GWP for N2O and CH4 are 298 and 25 respectively. For the purposes of making direct comparisons with soil C storage on these plots, the GWP values were converted to Ceq relative to C in CO2.

Soil C quantification

Then baseline soil cores were collected in June 2011 using 20cm depth increments up to a vertical depth of 2.4 m. Cores were extracted using a standard wet core diamond tipped drill bit with an internal diameter of 7 cm (Diamond Products Core Borer, Elyria, Ohio, USA). Each core barrel was inserted into the soil by a rotating hydraulic drill to minimize compaction within the barrel and to ensure accurate depth measurements. Soil samples were frozen at field moisture conditions until laboratory analysis. The cores were sieved at<2 mm and dried for 48 h at 105 ℃. Subsamples were ground to pass through a 250 micron sieve for heterogeneity, weighed, and analyzed for C concentration by combustion using a Costech ECS 4010 CNH Analyzer (Costech Analytical Technologies, Inc., Valencia, CA, USA). Soil C stock was determined with the equivalent soil mass method in increments of 3600 Mg ha?1 and a mean value for the baseline cores was determined at the 7200 and 18,000 Mg ha?1 reference masses, which represent the surface layer (25–40 cm) and deep profile (1–1.4 m) of soil.

Three soil cores (65-mm inner diameter bucket auger) were collected annually to a depth of 120 cm in 20 cm increments from each of the experimental plots. Samples were processed as noted above for the baseline cores for C concentration and soil C stock determination at the 18,000 Mg ha?1 reference mass. The change (?) in soil C stock was made for each plot by subtracting the mean baseline value from the mean of the three cores for each plot and was previously reported. The mean ?values for experimental years 1 and 2 were reported here as an annualized ?.

翻译译文

关于生物能源原料生产的潜在热带多年生牧草种植情景的碳预

算

摘要

背景:化石燃料消耗的环境成本得到全球承认，这为开发可持续替代燃料和能源选择的区域组合解决方案开辟了许多途径。本研究的目的是为夏威夷毛伊岛传统管理的甘蔗生产系统建立基准碳(C)预算，并将其与未来三种不同的能源种植方案进行比较:(1)50%不充分灌溉的传统甘蔗(甘蔗50%)，(2)100%充分灌溉的再生收获的狼尾草(狼尾草100%)，以及(3)50%不充分灌溉的再生收获的狼尾草（狼尾草50%）

结果:与再生收获和免耕管理下的收获前燃烧排放以及土壤碳储量相关的差异相比，农业投入和田间作业相关的化石燃料排放的种植场景之间的差异很小。传统甘蔗的燃烧排放量中碳当量接近一公顷一年2000千克；而在长有狼尾草的土壤表层的土壤碳当量收益约为一公顷一年4500千克。此外，深层土壤中的碳收益几乎是表层的三倍。因此，当包括深层土壤碳时，传统甘蔗的净全球变暖潜力最大，而狼尾草的净全球变暖潜力最小，为50%。每单位生物量产量中，温室气体最密集的情景是当甘蔗50%时，其指数(GHGI，在正值范围内，数值越高意味着气候变化加剧，因此在负值范围内，数值越低则更利于减缓气候变化)为0.11，最不密集的情景是在包括深层土壤时

(GHGI=-0.77)，狼尾草为50%。

结论:未来跨太平洋盆地或其他火山岛的前甘蔗地的能源或燃料生产情景应该集中在再生收获的作物上，这些作物在免耕管理下保持产量很长一段时间，并降低田间作业成本和农业投入需求。对于毛伊岛和其他地方的狼尾草来说，不充分灌溉最大限度地缓解了当地系统的气候变化，并且减少了用水应是规划可持续、多样化农业景观的一部分。

关键词:全球变暖潜力值，温室气体指数，狼尾草，宿根作物，甘蔗

背景

对从含木质纤维的作物生产可再生生物燃料的兴趣正在全球范围内得到认可，这是未来燃料市场的一种领先替代能源方案。主要由于2005年通过了《京都议定书》，与化石燃料消耗相关的负环境成本被国际水平得到确认和核算。从那以后，替代燃料的发展一直是像美国这样严重依赖进口化石燃料的国家的主要关注点。试验压力可能导致美国从传统的粮食作物农业转向生物能源系统，并且由于政府法规，可再生生物质原料的生产近年来已经加快。更具体地说，2007年的《能源独立和安全法》(EISA)等法规规定，到2022年，化石燃料源必须与至少360亿加仑可再生燃料混合，到2050年满足大约25%的液体燃料需求。为了支持国家政策，夏威夷也面临着来自2008年夏威夷清洁能源倡议(HCEI)的类似压力，该倡议要求当地，到2030年，夏威夷将开发出高效、可再生的燃料来源。该倡议明确要求在未来17年内用“当地生产的可再生能源”替代40%的州化石能源。燃料需求的增加可能会给已开发的农业用地带来额外的压力，如果不进行保守管理，会导致土地集约和转化。

如果管理不当，农业集约化会对土壤碳(C)储存产生负面影响，增加温室气体排放，并影响整个生态系统的碳平衡。在过去十年里，能源部门将一年一度的农田全部转化为常年的生物系统，这被认为是通过改善土壤质量和减少营养改良来提供温室气体缓解潜力的。然而，近年来，对这些系统缓解潜力的确认结果提出了关于真实系统温室气体水平的问题。由于气候变化，世界生产性耕地的短期和日益严重的缺水状况变得更加严重，导致世界生物燃料种植面积增加的可持续性更加不确定。由于在生物能源问题上存在一系列矛盾的观点，证明这些不确定性的地方和区域数据集的记录是至关重要的。

因为这些农业系统在作物种植实践、土地管理和设备使用方面存在巨大差异，生物燃料生产的温

室气体总量平衡难以捕捉。此外，许多最近的研究集中在单一物种的场景上，这些场景专门针对巴西乙醇生产，并不完全适用于解决他们研究领域以外的区域问题。尽管这些研究可以成为在大型农业基础设施下推进生物能源生产的全球暗示的有力工具，还需要额外的小规模研究来评估这些系统之间的交易，并在当地范围内提供替代性的管理方案。为此，需要根据特定地点的数据使温室气体平衡，其中包括建立和维持生物能源种植系统所需的能源投入(化石和非化石燃料)。对于这些温室气体评估中的大多数，化石能源投入是利用排放系数换算成二氧化碳当量(CO2eq)。被称为全球变暖潜能值(GWP)，这些二氧化碳当量在国际范围内具有可比性。这种温室气体的核算允许农业生产排放的温室气体和生产可再生燃料来源节省的温室气体直接比较。为了温室气体核算的目的，所有排放物都被转换成类似的碳当量(Ceq)，以便与每种种植方式下储存的土壤碳量进行直接比较。这种C预算将这些系统的全球升温潜力值与作物产量相关联，这允许对生产系统的总体温室气体强度进行估计。

迄今为止，还没有关于夏威夷农业经营的已知C预算，这使得将未来的种植前景与当前的做法进行比较成为不可能。超过11，000公顷的毛伊岛是国家指定和保护的农业用地，该地区未来的可持续性可能取决于采用一种能源作物方案，这种方案能够消除基于化石燃料的温室气体排放。这项研究的目的是为(100%灌溉)毛伊岛传统管理的甘蔗生产系统建立一个基准C预算，并将其与三种不同的未来能源种植方案进行比较:[1)50%不充分灌溉的传统甘蔗(甘蔗50%)，[2]100%灌溉的再生收获狼尾草(狼尾草100%)，[3)50%不充分灌溉的可再生收获的狼尾草(狼尾草50%)。这种对比将有助于根据他们的农业碳预算，在夏威夷和其他在太平洋岛屿的一些国家建立未来生物燃料生产的最佳方案。

田间在研究期间，HC＆S是夏威夷唯一剩下的甘蔗种植园。莫洛凯岛的实验地块处于高度风化状态，田实验在毛伊岛中部（北纬20.89，西经156.41）的夏威夷商贸和制糖公司（HC＆S）的土地上进行。间非常精细，含有高岭石以及温热的典型饱和干旱氧化土，海拔约100米，总商业面积达72公顷。土壤透水性好，岩石多，土层深厚，耕层清晰。如2011年基线土壤收集所评估的那样，土壤的酸碱值（pH）为7.97，在其顶部40 厘米处，土壤碳（C）浓度平均为1.37％，平均堆积密度为1.51克立方厘米。实验期间，其年平均气温为23.4摄氏度，年降水量为241毫米，与该地区的长期平均值一致。

该实验是在条状地块进行的群体平衡设计，该设计有两个因素，灌溉和物种，并且灌溉和物种有三个重复（块）（更多细节详见16）以标准种植率（100％）和以两种不足的灌溉率（标准种植率的75％和50％）灌溉。最初的试验包括4种，甘蔗（Saccharum officinarum），能源甘蔗（Saccharum officinarum x Saccharum spontaneum），狼尾草（Pennisetum purpureum Schumach。）和糖高粱（Sorghum bicolor（L.）Moench）。在这项研究中，对这两种作物（甘蔗和狼尾草）在两个灌溉水平（50％和100％）进行了评估。 2011年6月26日，在最近收获的甘蔗田中建立了田间地块，并且甘蔗轮作已经进行了100多年。在HC＆S种植园内的邻近田地种植了甘蔗，并且狼尾草种子作物是由瓦胡岛威玛纳诺的夏威夷大学研究站的收获人口提供的。

从2011年11月13日起，根据种植园的水供应情况，将不充分灌溉的方法应用于种植田地，并使用自动计时器进行控制。从2011年11月至2012年10月，将每公顷1245毫米的水施加到100％的地块上，将每公顷633毫米的水施加到50％的地块上，实际上却是50.8％的不充灌溉。在研究期间，2012年3月13日和2012年9月25日，每6个月（产量最大化的时间间隔）收获一次狼尾草地块。甘蔗作物在2年的增长轮作中，在研究期间没有达到成熟，因此没有收获。

开发甘蔗基准系统

甘蔗是南太平洋高产的热带碳4多年生植物。夏威夷的热带甘蔗生物量产量每年高达每公顷干重量40毫克，而巴西的热带甘蔗产量每年为每公顷干重量26毫克。该品种支持抗旱，具有健壮的根系，可以改善土壤结构，并在边缘土地上积累碳。然而，夏威夷甘蔗已经生长了2年，24个月后达到成熟，然后在低强度燃烧后收获随后进行深耕和机械化种植。毛伊岛商业甘蔗的生产超过125年。然而，2016年1月，最后留下的大型食糖生产商HC＆S宣布将其14,000公顷的种植用地转变为多种农

业发展用地，包括种植多年生草本植物，用于饲料，牧草和生物能源原料。

制定碳预算或温室气体的分析包括生产特定作物所需的农业投入的详细说明。这包括量化化石燃料和基于非化石燃料的排放。化石燃料的排放被认为是在田间准备，种植，农用化学品的使用，农作物的收获和维护所使用燃料产生的排放。非化石燃料的排放被认为是生物温室气体排放，其产生的二氧化碳（CO2），甲烷（CH4）和一氧化二氮（N2O）是生产系统的结果，而且主要是采前焚烧作业，土壤温室气体交换和残留物管理的结果。该基准系统将被称为甘蔗100％的情景，以供未来比较。

燃料消耗和农业投入产生的化石燃料排放

田间作业

田间作业（即田间准备，收获，制造和维护，育种和灌溉）通常被认为是隐藏的排放源，因为它们对温室气体通量有间接影响。这些排放是在设备操作期间化石燃料的燃烧引起的，并且由于描述性能量单位变化大，计算有些困难。在田间作业中使用标准单位千克·碳当量(kg Ceq），有助于对碳预算总量的评估。排放因素（EF）用于将每次作业的燃料使用的需求量转换为碳当量。该分析中使用的排放因素（EF）是所有文献中提供的最佳值和最新值。通过与种植园工作人员的个人交流，获得了有关设备类型和用途的具体信息。

尽管文献中发现的排放因子不足以描述毛伊岛的田间作业，但是它们独立存在，能够最好地反映当前的种植方法。例如，灌溉排放量是根据以特定于毛伊岛的比率0.057 升/千瓦时（与杰克维·李的个人交流，HC＆S化学工程师，2013年）将种植水泵送到种植园所需的平均能量计算的。此外，调整该值以计算2011到 2012年应用于田间的总水量，以正确反映种植园在这些作业中使用可再生能源的数量（可再生能源与化石能源比率大约为3：1）。甘蔗基准情景的另一项投入是计算与甘蔗种植相关的化石燃料排放，并根据种植过程中使用的甘蔗苗的重量进行调整。

农业投入

农业投入物（即肥料，除草剂和石灰）的排放是生产，运输和分配这些物品所需能源的结果。一种芽前除草剂混合物，含有阿特拉津（1-氯-3-乙基氨基-5-异丙基氨基-2,4,6-三嗪），2,4-D[植物生长素]（2,4-二氯苯氧基乙酸），除芽通（（N-1） - 乙基丙基）-3,4-二甲基-2,6二硝基苯 - 烯胺），赖夫（3,6-二氯-2-甲氧基苯甲酸）和威尔柏（3-环己基-6-二甲氨基-1-甲基-1,3）在种植三周后，施用5-三嗪-2,4（1H，3H） - 二酮一次。每个样地通过滴灌每公顷施用345千克的氮肥（液体尿素：46-0-0）。作物一旦种植，会在10个月后结束，每月需施用一次肥料。对于两年生长期的甘蔗作物，基于当前的HC＆S种植实践优化了尿素施用的时间和速率，在所有的施肥活动期间推迟了不充分灌溉处理。

毛伊岛甘蔗生产中农业投入产生的碳排放的定量基于施用率并转换为碳当量，报告为排放因子。使用0.97的排放因子将肥料施用率转化为碳当量。石灰（碳酸钙）应在田间种植前以每公顷2569千克的比率施用，并使用0.12的排放因子将其施用率转化为碳当量。确定了HC＆S报告中的除草剂混合物使用的每种化学品的个体排放因子，然后对这些因子进行了平均化分析，并为毛伊岛特有的除草剂应用开发了新的排放因子（5.64）。

非化石燃料排放

凋落物的分解

凋落物分解产生的排放是残留物管理的一个函数。例如，由于收获后叶片的分解，一氧化氮的排放量会增加，与焚烧过的田地相比，更具完整性。毛伊岛甘蔗田的目标是保持作物残渣占总田间生物量的15％。使用这个百分比，可以根据HC＆S报告的平均生物量的产量每年每公顷80.4 毫克计算凋落物的碳当量。凋落物分解的排放因子是基于收获之后作物残留物中氮的含量。

收获前的燃烧排放量

夏威夷常规的甘蔗种植包括收获前的低强度焚烧，以便于在收获前去除不需要的叶状物质。通过生产甲烷和一氧化氮以及释放到环境中的黑碳（BC），收获前燃烧明显增加了温室气体的排放。对于毛伊岛种植方案的价值是基于总田间生物量的15％的残留物保留率。2006年国家温室气体清

单评估指南中列出的现行IPCC值表明，每吨干物质燃烧会产生0.07千克一氧化氮排放因子和2.7千克的甲烷排放因子。黑碳在100年的时间范围内的全球变暖潜能值比二氧化碳大500倍，而且估计一公斤的黑碳是由一公斤的垃圾烧制产生的。

土壤中一氧化氮和甲烷的排放

正如先前的详细报告（帕洛斯基等人的综述中）那样，甲烷和一氧化氮中土壤通量的田间测量始于2011年10月，并且按照GRACEnet采样方案，至少每月进行一次采样直至2012年10月。从安装在甘蔗和狼尾草行与行间的永久钢圈上密封的静态PVC室收集上午十点的测量结果。样品的收集是通过密封每个室并使用10毫升的聚丙烯注射器，在室关闭后0,15,30,45和60分钟后，通过苯乙烯盖上的隔膜抽取8毫升顶空空气。每个气体样品立即注入装有硅化物/硅氧烷的真空试管?（英国拉布科有限公司）用于短期储存。样品是通过使用岛津GC-2014气相色谱仪（岛津科学仪器公司）分析，这种测谱仪使用一种出名的电离检测器测量甲烷化后甲烷和二氧化碳的浓度，以及用于分析一氧化氮的电导率检测器。通过假设气体浓度随时间的线性变化来计算通量率。一氧化氮和甲烷的累积年排放量从第一年的每日通量和夏季通量进行插值，并以每年每公顷多少千克的甲烷和一氧化氮的形式进行报告。为了探讨碳平衡方面的一氧化氮和甲烷的排放，通过使用IPCC 100年内的影响因素计算全球变暖潜力值，将年通量率转换为二氧化碳当量。因此，在100年的时间范围内，当二氧化碳当量等于1时，则一氧化氮和甲烷的全球变暖潜力值分别为298和25。为了与这些地块上的土壤碳储量直接比较，相对于二氧化碳中的碳，将全球变暖潜力值转换为碳当量。

然后在2011年6月通过使用20厘米深度增量，并且垂直深度达2.4米，进而收集基准土芯。并且使用内径为7厘米的标准湿芯金刚石尖头钻头（美国俄亥俄州伊利里亚生产的金刚石钻芯机）提取土芯。通过旋转液压钻将每个土芯筒插入土壤中，并将桶内压实至最小化，以确保精确的深度测量。在田间湿度条件下，土壤样品冷冻直至被带回实验室分析。将小于2毫米的岩心过筛并在105摄氏度的条件下干燥48小时。将子样品研磨以通过250微米过筛进行不均匀性分析，称重，并使用科斯泰克ECS 4010 CNH元素分析仪（美国加州瓦伦西亚科斯泰科分析科技公司）通过燃烧分析碳浓度。土壤碳储量用等效土壤质量法测定，以增量为每公顷3600毫克，基准土芯的平均值在每公顷7200和18,000毫克参考储量测定，该参考储量代表了土壤的表层（25-40 厘米）和土壤的深剖面（1-1.4米）。

每年从每个实验地块以20厘米的增量达到120厘米的深度收集三个土芯（65mm内径桶式螺旋钻）。在每公顷18,000 毫克的参考储量下，如上所述用于土壤碳浓度和土壤碳储量测定的基准核心的样品处理中，通过从每个地块的三个土芯平均值中减去平均基准值，得出每个地块土壤碳储量的变化（Δ），这在先前已经报告过。这里把在报告中实验年份为1和2的平均变化值作为年度变化值。