基于生命周期评价的我国稻米碳足迹核算

党的二十大报告强调，我们要积极稳妥推进碳达峰碳中和。民以食为天，粮食是维持人类生命的基本需求，粮食从生产、加工、运输、使用以及废弃处理等各阶段的能源消耗及其对环境的影响，近年来开始受到国内外的广泛关注。文中基于生命周期理论，利用实地调研数据结合相关文献，分析计算我国稻米生命周期各阶段的碳排放。结果显示：每千克普通稻米的碳排放为1.1492kg,农业生产阶段为稻米碳排放的主要阶段，占据碳排放总量的47.46%,其次为使用阶段占27.91%、加工阶段和运输阶段各占18.28%和6.10%,废弃处理阶段最少不足0.26%;每千克有机稻米的碳排放为1.4042kg,同样是农业生产阶段为碳排放消耗的主要阶段，占据碳排放总量的49.52%,其次为使用阶段占22.84%、加工阶段和运输阶段各占14.96%和12.11%,最后为废弃处理阶段仅占0.57%。研究认为，每千克有机米的碳排放量显著高于普通米的碳排放量，这与有机米的产量较低有关。文中建议通过对稻米原料阶段的生长技术进行改善、大力推行农产品地产地消等方式降低稻米的碳排放。     

中国大陆秸秆露天焚烧的经济损失研究

分析了全国焚烧秸秆集中的地区,并根据2001-2004年各省市农作物的产量和谷草比例,计算了全国和各省市农业秸秆的产量,全国农业秸秆产生量大约为6×108t/年,其中稻谷、小麦、玉米3种秸秆共占总量的76%左右。采用曹国良等人对各地区的焚烧比例,计算出2004年中国大陆各省市的秸秆焚烧量,并结合排放因子确定了秸秆燃烧产生的各污染物清单,从而估算出直接生物资源损失为113.4亿元,造成的大气污染损失为196.5亿元。     

1997-2015年中国种植业碳排放时空特征及与农业发展的关系

基于我国1997~2015年种植业生产过程中农用物资(化肥、农药、农用塑料、灌溉和农业机械)投入所引起的碳排放,揭示我国种植业自1997~2015年碳排放时空分布规律的特征,并分析种植业碳排放与农业经济增长之间的关系。结果表明:2015年我国种植业碳排放总量为9671万t,较1997年增加了51%,而种植业碳排放增速呈现出明显的"下降-上升-下降"的变化特征;不同碳排放源中,化肥使用是中国种植业碳排放的主要来源,占排放总量的56%;碳排放增速具有显著的地域性,西部和东北地区碳排放增速高于东部、中部地区;自1997~2015年中国单位GDP碳排放比逐渐降低,并且地区之间差异减小;目前中国种植业碳排放与农业GDP符合EKC曲线:在东部、中部和东北地区种植业碳排放与农业GDP处于脱钩状态,而西部地区种植业碳排放与农业GDP仍处于耦合状态。我国种植业碳排放基本进入低碳发展的模式,但地区之间碳排放差异较大。     

基于LMDI模型的东北地区农业碳排放测度与分解

通过对东北三省的农业碳排放进行测度,并基于LMDI(对数平均迪氏分解)模型将其分解为碳排放强度、农业收入、就业结构与人口总量四种驱动效应。研究结果:(1)从东北地区的农业碳排放总量来看,1996—2013年间黑龙江、吉林和辽宁三省的农业碳排放呈现逐年上升的趋势,分别增加了0.72、0.63倍和0.52倍,年平均增长率分别为3.23%、2.92%和2.51%,黑龙江碳排放总量和增速最大;(2)从东北地区农业碳排放的内部结构来看,农用资本与农地利用带来的碳排放是东北地区的主要碳源,占比58.65%,其次是牲畜养殖碳排放,占比22.59%;(3)碳排放强度效应对农业碳排放的影响为负,且表现出黑龙江辽宁吉林的特征;1996—2013年间,农业收入效应推动黑龙江、吉林和辽宁的农业碳排放分别增加了1480.57、883.17万t和839.10万t;就业结构效应对黑龙江和辽宁的农业碳排放有正向影响,但对吉林则呈现显著的负向作用;人口总量效应对农业碳排放总量的影响均为正,驱动辽宁的农业碳排放增加了51.02万t。     

2018-2021年新疆昌吉市棉田农药使用情况调查与分析

本文对昌吉市主要棉田和农资市场进行调查分析,研究昌吉市棉田农药使用状况及其结构,为有效开展棉田农药减施提供参考依据。结果表明,2018—2021年昌吉市棉田平均每年农药施用折百总量约为86.45 t,其中杀虫杀螨剂、杀菌剂、除草剂和植物生长调节剂施用量分别占农药总量的22.21%、16.34%、37.65%和23.80%;而2021年昌吉市棉田农药使用总量折百量为83.89 t(其中,除草剂、植物生长调节剂、杀虫杀螨剂和杀菌剂分别占比为29.92%、29.20%、21.62%和19.26%),同比2018年农药使用总量减少9.19%,棉田农药使用量实现负增长。     

我国农药使用监管现状及对策研究

<正>依法推行农药使用监管,确保科学、合理、安全用药,是充分发挥农药效能,避免不良效应的必要手段,对于提高农作物产量,提升农产品品质,保障农业生产安全、农产品质量安全、生态环境安全,具有十分重要作用。1我国农药使用与监管的现状1.1农药使用现状1.1.1农药用量和品种结构2013年全国农作物使用农药总量约33万吨(折百量,下同),其中:杀虫剂13万吨,占39.4%;杀菌剂8万吨,     

无公害农产品与农药控制技术

农药是重要的农业生产资料,占总量90％以上的农药都是通过化学合成的,它们在防治农作物病、虫、草、鼠害,保证农业生产丰收中起到了巨大的作用,但同时也对环境和人类的健康带来了一定的威胁。我国是农药生产和使用大国,高毒农药的生产和使用量占70％(其中有机磷占70％,而5种高毒     

让市场筛选优势农药品种

<正>农业部组织有关专家,根据农药品种毒性、残留限量标准、农业生产使用及风险监测等情况,对已取得正式登记的农药品种进行筛选、评估,制定并推出了2014年版《种植业生产使用低毒低残留农药主要品种名录》(以下简称《品种名录》)。从在我国取得农药登记的700余种农药有效成分中筛选出91个农药有效成分,仅占14%左右。在入选的91个农药品种中,杀虫剂29个,占32%;杀菌剂40个,占44%;除草     

严格高毒农药管理 保证农产品用药安全

农药是重要的农业生产资料,占总量90％以上的农药都是通过化学合成的,它们在防治农作物病、虫、草、鼠害,保证农业生产丰收中起到了巨大的作用,但同时也对环境和人类的健康带来了一定的威胁。我国是农药生产和使用大国,高毒农药的生产和使用量占了70％(其中有机磷又占70％)。为了减少高毒农药带来的危害,近几年来,国家采取了一     

京郊京白梨果园生产系统碳源/汇特征分析

作为一类农业生产系统,果园在森林生态系统碳循环中扮演着重要角色。本研究以北京市门头沟区军庄镇孟悟村京白梨标准化生产示范基地为对象,对其2015年度的碳源/汇特征进行了分析。结果表明:该生产系统碳排放总量为7502.40kg Ce,强度为375.12kg Ce/hm2,灌溉消耗电能造成的碳排放占总量比例最高,为46.76%;系统内植被碳吸存总量为57979.02kg C,强度为2898.95kg C/hm2,果园套种作物对系统碳吸存贡献最大,占总量的79.47%;系统碳效率为7.73kg C/kg Ce。总体上,该生产系统为碳汇,具备较强的生产可持续性,同时,实施果树节水灌溉,借助雨洪利用工程减少果园灌溉对地下水的依赖,及合理套种林下作物,是进一步提升其节碳增汇水平的有效途径。     

农田土壤有机碳的影响因素及其研究

大气温室效应气体N2O、CO2增多与全球气温变暖有着密切的关系,由于农业活动导致的碳排放量占碳总排放量的25%,因此研究农田土壤有机碳的影响因素,对增加农田碳素固定和保持,减少由于不合理的土地使用而导致大量CO2的排放,维持农业和生物圈生态系统的可持续发展有着重要意义。本文分析了温度、水分、土地开垦、休闲和撩荒、耕翻、轮作、秸秆还田、肥料管理等对土壤有机碳的影响。减少翻耕次数,增加秸秆还田,优化氮、磷、钾等养分用量及配比,是提高农田,尤其是旱地农田土壤有机碳含量,培肥、改良土壤的重要途径。     

A comparison of GHG emissions from UK field crop production under selected arable systems with reference to disease control

Crop disease not only threatens global food security by reducing crop production at a time of growing demand, but also contributes to greenhouse gas (GHG) emissions by reducing efficiency of N fertiliser use and farm operations and by driving land use change. GHG emissions associated with adoption of reduced tillage, organic and integrated systems of field crop production across the UK and selected regions are compared with emissions from conventional arable farming to assess their potential for climate change mitigation. The reduced tillage system demonstrated a modest (<20%) reduction in emissions in all cases, although in practice it may not be suitable for all soils and it is likely to cause problems with control of diseases spread on crop debris. There were substantial increases in GHG emissions associated with the organic and integrated systems at national level, principally due to soil organic carbon losses from land use change. At a regional level the integrated system shows the potential to deliver significant emission reductions. These results indicate that the conventional crop production system, coupled to reduced tillage cultivation where appropriate, is generally the best for producing high yields to minimise greenhouse gas emissions and contribute to global food security, although there may be scope for use of the integrated system on a regional basis. The control of crop disease will continue to have an essential role in both maintaining productivity and decreasing GHG emissions.     

Impacts of chemical crop protection applications on related CO2 emissions and CO2 assimilation of crops

BACKGROUND: A major global challenge is to provide agricultural production systems that are able to sustain growing demands for food, feed, fibre and renewable raw materials without exacerbating climate change. Detailed and reliable data on the CO₂ balance of different agricultural management activities and inputs as a basis to quantify carbon footprints of agriculture are still lacking. This study aims to fill this gap further by quantifying the net balance of emitted and assimilated CO₂ due to the application of crop protection treatments on the farm, and by assessing their partial contribution to GHG emissions and mitigation in agriculture. The study focuses on key agricultural crops including wheat, corn, oilseeds and sugar crops. RESULTS: The final CO₂ balance, considering GHG emissions due to on‐farm CPP treatment in comparison with CO₂ storage in additional biomass, CO₂ protected with respect to agrotechnical inputs and land inputs and CO₂ saved with respect to associated global land use changes, is positive and may reach multiples of up to nearly 2000. CONCLUSION: The results highlight the importance of the positive yield effects of the CPP programme applications on the farm, resulting in additional assimilated biomass at the farm level and less land use changes at the global level, and thus lower pressure on environmentally important indicators of overall agricultural sustainability. Copyright © 2012 Society of Chemical Industry     

Rapid mineralisation of the herbicide isoproturon in soil from a previously treated Danish agricultural field

Mineralisation of the phenylurea herbicide isoproturon (3-(4-isopropylphenyl)-1,1-dimethylurea) and two of its known metabolites, 3-(4-isopropylphenyl)-1-methylurea (monodesmethyl-isoproturon) and 4-isopropylaniline, was studied in Danish agricultural soils with or without previous exposure to isoproturon. A potential for rapid mineralisation of isoproturon and the two metabolites was present in soils sampled from three plots within an agricultural field previously treated regularly with the herbicide, with 34-45%, 51-58% and 33-36% of the added [phenyl-U-14C]isoproturon, [phenyl-U-14C]monodesmethyl-isoproturon and [phenyl-U-14C]4-isopropylaniline metabolised to [14C]carbon dioxide within 30 days at 20 degrees C. In contrast, such extensive mineralisation of these three compounds was not observed within this period in soils sampled from two other agricultural fields without previous treatment with isoproturon. The mineralisation patterns indicated growth-linked metabolism of the three compounds in the previously exposed soils, and doubling times for [14C]carbon dioxide production ranged from 1.6 to 3.2, 1.0 to 2.1 and 1.3 to 1.7 days for isoproturon, monodesmethyl-isoproturon and 4-isopropylaniline, respectively. The ability to mineralise [phenyl-U-14C]isoproturon to [14C]carbon dioxide was successfully sub-cultured to a fresh mineral medium which provided isoproturon as sole source of carbon and nitrogen. One of the soils sampled from an agricultural field not previously treated with isoproturon showed accelerated mineralisation of [phenyl-U-14C]4-isopropylaniline toward the end of the experiment, with a doubling time for [14C]carbon dioxide production of 7.4days. This study indicates that the occurrence of rapid mineralisation of the phenyl ring of isoproturon to carbon dioxide is related to previous exposure to the herbicide, which suggests that microbial adaptation upon repeated isoproturon use may occur within agricultural fields.     

秸秆还田量对陇中旱作麦田土壤团聚体稳定性和有机碳含量的影响

为探明秸秆还田后土壤团聚体与有机碳的变化特征和作用机制,依托2019年布设于甘肃省定西市李家堡镇的不同秸秆还田试验,设置两种秸秆类型：小麦秸秆和玉米秸秆,秸秆还田量分别为：0（CK）、3 500（低量）、7 000（中量）、14 000 kg·hm^-2（高量）,研究了秸秆还田对陇中黄土高原旱作农田土壤团聚体稳定性和有机碳的影响。结果表明：土壤机械稳定性团聚体以>0.25 mm团聚体为主,且随土层加深粒径逐渐增大,水稳性团聚体均与之相反;秸秆还田较不还田处理的机械稳定性和水稳性<0.25 mm粒级团聚体含量分别降低了3.53%～21.74%和2.73%～8.95%,土壤机械稳定性和水稳性团聚体平均重量直径MWD、几何平均直径GMD的提升幅度最大分别达到16.29%、30.12%和20.93%、12.12%,团聚体破碎率PAD降低了2.53%～13.23%,在中量秸秆还田时效果最好,且玉米秸秆比小麦秸秆效果更明显。秸秆还田提升了土壤有机碳含量,且在表层土壤秸秆还田量越高,对土壤有机碳的提升效果越显著,其中玉米秸秆高量还田处理的土壤有机碳含量较CK显著提高了...     

近20年新疆农田生态系统碳足迹时空变化

利用1994—2013年新疆农田生产投入和农作物产量等数据,采用碳排放系数法估算了新疆农田生态系统的碳排放量、碳吸收量及碳足迹的变化动态以及在各县市的空间分布特征。结果表明:新疆农田生态系统的碳排量从1994年的179.46万t增长到2013年的474.15万t;不同年份农业碳排放均主要源于化肥使用量的增加和不科学的灌溉方式,其最大贡献率分别为40.02%和41.56%;农田生态系统的碳吸收量20年间增加了2185.04万t,棉花对新疆农田生态系统的碳吸收量贡献最大,多年平均贡献率达47%;新疆农田生态系统的碳排放量、碳吸收量区域主要集中在南疆的县市并呈现出沿天山对称的趋势;1994—2013年,农田生态系统碳足迹呈现快速增长态势,从1994年的2 732.63×104C·hm-2·a-1增加至2013年的4 474.89×104C·hm-2·a-1,碳足迹增加了283.59×104C·hm-2·a-1,表明新疆农田生态系统存在碳生态盈余的现象,种植结构生态效益指数大于1的年份为11个,种植结构的调整迫在眉睫。     

连续施用农业废弃物组合肥制种玉米田理化性质及酶活性和重金属变化特征

在甘肃省进行了连续4 a施用农业废弃物组合肥制种玉米田理化性质及酶活性和重金属变化特征研究。 结果表明：农业废弃物组合肥施用量比例为秸秆组合肥18 t·hm^-2∶畜禽粪便组合肥36 t·hm^-2∶废渣组合肥15 t·hm^-2。施用农业废弃物组合肥4 a与不施肥比较,制种玉米田容重、pH值和真菌数量分别降低6.77%、6.20%和26.19%;总孔隙度、水稳性团聚体、总持水量、EC值、可溶性盐和CEC分别增加6.63%、18.95%、6.62%、5.23%、5.36%和36.10%;有机质、有机碳、有机碳密度、碱解氮、速效磷和速效钾含量分别增加23.72%、24.10%、15.48%、28.44%、49.92%和27.97%;细菌数量、放线菌数量、蔗糖酶、 脲酶、磷酸酶和多酚氧化酶活性分别增加38.20%、86.60%、63.46%、38.89%、61.48%和58.82%;Hg、Cd、Cr、Pb和Zn含量分别增加21.74%、30.00%、24.49%、27.55%和31.81%。农业废弃物组合肥施用年限与制种玉米田容重、pH值和真菌数量之间呈显著负相关关系,与总孔隙度、水稳性团聚体、CEC、EC值、可溶性盐、总持水量、有机质、有机碳密度、速效氮磷钾含量、细菌数量、放线菌数量、酶活性、重金属含量之间呈显著正相关关系。 虽然连续4 a施用农业废弃物组合肥重金属含量比不施肥高,但重金属含量小于土壤污染临界值,说明研究区域农业废弃物组合肥重金属含量较低,不会对作物造成风险。     

不同覆盖方式对温室葡萄耗水规律和产量的影响

为筛选出适合河西走廊地区的日光温室葡萄最佳覆盖模式,在张掖市水务局灌溉试验站,设白膜+秸秆覆盖、黑膜+秸秆覆盖、白膜覆盖、黑膜覆盖、秸秆覆盖和砂子覆盖等不同覆盖处理,对温室葡萄耗水规律和产量表现进行了研究分析。结果表明:1不同覆盖方式均可增加土壤含水量,秸秆+黑膜覆盖下的土壤含水量最大,全生育期内秸秆+黑膜覆盖下的土壤相对含水量达到了16.54%,单一的秸秆覆盖的土壤含水量在中后期也增大较快,土壤含水量增大到了17.64%,秸秆+地膜双重覆盖与单一的秸秆覆盖在中后期均能明显提高土壤储水能力;2不同覆盖处理相比对照(不覆盖)均能增加葡萄产量,以黑膜+秸秆覆盖葡萄的增产效果最好,增产高达28.85%(P0.05),白膜+秸秆覆盖增产25.53%(P0.05);3不同覆盖处理均能调节土壤温度,地膜+秸秆覆盖方式兼备了单一地膜和单一秸秆覆盖处理的特点,前期土壤升温幅度大于秸秆覆盖,后期降温趋势小于地膜覆盖,且以黑膜+秸秆覆盖较为明显,其处理下土壤温度保持在21.13℃左右;4各覆盖处理均可提高灌溉水利用效率(IWUE)和水分生产效率(WUE),达到节水增产的目的,以黑膜+秸秆效果最好,黑膜+秸秆覆盖处理的灌溉水利用效率和水分生产效率均最大,分别达到了6.53 kg·m~(-3)和5.88 kg·m~(-3)。     

Corn straw return can increase labile soil organic carbon fractions and improve water-stable aggregates in Haplic Cambisol

Corn straw return to the field is a vital agronomic practice for increasing soil organic carbon (SOC) and its labile fractions, as well as soil aggregates and organic carbon (OC) associated with water-stable aggregates (WSA). Moreover, the labile SOC fractions play an important role in OC turnover and sequestration. The aims of this study were to determine how different corn straw returning modes affect the contents of labile SOC fractions and OC associated with WSA. Corn straw was returned in the following depths: (1) on undisturbed soil surface (NTS), (2) in the 0-10 cm soil depth (MTS), (3) in the 0-20 cm soil depth (CTS), and (4) no corn straw applied (CK). After five years (2014-2018), soil was sampled in the 0-20 and 20-40 cm depths to measure the water-extractable organic C (WEOC), permanganate oxidizable C (KMnO₄-C), light fraction organic C (LFOC), and WSA fractions. The results showed that compared with CK, corn straw amended soils (NTS, MTS and CTS) increased SOC content by 11.55%-16.58%, WEOC by 41.38%-51.42%, KMnO₄-C and LFOC by 29.84%-34.09% and 56.68%-65.36% in the 0-40 cm soil depth. The LFOC and KMnO₄-C were proved to be the most sensitive fractions to different corn straw returning modes. Compared with CK, soils amended with corn straw increased mean weight diameter by 24.24%-40.48% in the 0-20 cm soil depth. The NTS and MTS preserved more than 60.00% of OC in macro-aggregates compared with CK. No significant difference was found in corn yield across all corn straw returning modes throughout the study period, indicating that adoption of NTS and MTS would increase SOC content and improve soil structure, and would not decline crop production.