黄土高原雨养农业区不同种植模式土壤温室气体排放特征   总被引：1，自引：0，他引：1  

邓长芳  罗珠珠  李玲玲  牛伊宁  蔡立群  张仁陟  谢军红 《草业学报》2018,27(9):1-13

研究陇中黄土高原旱作农田,设置了苜蓿-苜蓿(L-L)、苜蓿-休闲(L-F)、苜蓿-小麦(L-W)、苜蓿-玉米(L-C)、苜蓿-马铃薯(L-P)和苜蓿-谷子(L-M)6个处理,采用静态箱-气相色谱法和碳通量测量系统LI-8100对苜蓿后茬轮作不同作物土壤温室气体排放动态及其影响因素进行了测定与分析。研究结果表明,农田土壤表现为CO₂源、N₂O源和CH₄吸收汇,且呈现夏秋高,春冬低的季节性变化特征。L-L处理的CO₂累积排放量最高,L-W处理较之降低了42.43%;L-C处理的N₂O累积排放量最高,L-P处理最低;CH₄吸收量以L-M处理最高,较L-F和L-L分别增加了62.71%和31.87%,综合增温潜势表现为L-L>L-M>L-C>L-P>L-F>L-W。相关分析结果表明,CO₂、CH₄、N₂O排放量与脲酶、过氧化氢酶活性及土壤温度呈极显著相关(P<0.01),与土壤水分在不同土层有显著相关性;逐步回归分析发现,土壤温度、过氧化氢酶是CO₂和CH₄排放的主导因素,土壤温度极显著影响气体排放,N₂O排放主要受到环境因子的影响。综合来看,与长期苜蓿连作相比,黄土高原地区苜蓿种植一定年限之后轮作粮食作物能减少土壤温室气体排放量,减弱农田温室气体的增温效应,其中以小麦效果最佳。  相似文献   

Dose–response effect of a pine bark extract on in vitro ruminal ammonia and methane formation kinetics     

N. Vera  C. Gutiérrez  R. Allende  P. Williams  C. Fuentealba 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2018,68(4):181-189

ABSTRACT

This study assessed the potential of a pine bark extract (PBE) to decrease methane (CH₄) and ammonia nitrogen (NH₃-N) production in vitro. Dietary substrates, mixed hay, soybean meal and corn grain, were supplemented 0, 2, 4 and 6% of PBE and incubated in an in vitro batch culture for 24-h. Incubations were run three times. Total gas production (GP) was determined at 6, 12 and 24-h and gas samples were analysed for CH₄. Samples were collected for volatile fatty acids (VFA) and NH₃-N analysis. Treatments were compared by polynomial contrasts for PBE concentration. Increasing PBE caused linear decreases in NH₃-N, microbial biomass production and digestibility, whereas the degradation rate was quadratically reduced. Total VFA were decreased but total GP and CH₄ production and kinetics were unaffected. The inclusion of 2% PBE in ruminant feed has the capability to reduce NH₃-N concentration by 50%, without affecting diet digestibility or CH₄ production.  相似文献   

改善低毒脲醛树脂微观结构的方法     

顾丽莉  宋红 《四川林业科技》1998,19(4):26-30

本研究通过理论研究和实验探索，采用适当降低缩聚段的ｐＨ值和引入缩醛化反应，从而改善了树脂的微观结构，得到不脱水低毒脲醛树脂胶，其性能达到ＧＢ／Ｔ１４７３２－９３要求，制得的刨花板满足ＧＢ／Ｔ４８９７－９２Ａ类板一等品要求，甲醛释放量达到欧洲Ｅ２级。  相似文献   

南方双季稻区不同复种方式对稻田综合温室效应的影响   总被引：1，自引：0，他引：1  

伍思平  眭锋  肖小军  张俊  吴自明  曾勇军  黄山 《核农学报》2020,34(2):376-382

为明确南方双季稻区不同复种方式对稻田综合温室效应和温室气体排放强度的影响,试验设置油菜-一季中稻(R-MR)、冬季绿肥(紫云英)-早稻-晚稻(GM-ER-LR)、冬闲-早稻-晚稻(WF-ER-LR)3个处理,采用静态暗箱-气相色谱法监测周年温室气体排放,探明不同复种方式对周年作物产量、稻田全球增温潜势(GWP)、籽粒能量产出(GEY)和全球增温潜势强度(GWPI)的影响。结果表明,与R-MR相比,GM-ER-LR和WF-ER-LR显著增加了CH₄累积排放量(分别提高1.27倍和1.18倍),显著降低了N₂O累积排放总量(分别降低34.1%和49.4%),GM-ER-LR和WF-ER-LR的CH₄和N₂O累积排放量无显著差异。与R-MR相比,GM-ER-LR和 WF-ER-LR显著提高了周年GEY(分别提高28.6%和27.0%)。在100年时间尺度上,GM-ER-LR和WF-ER-LR的稻田GWP分别是R-MR的1.27倍和1.18倍,GWPI分别较R-MR提高100%和50%。因此,GM-ER-LR和WF-ER-LR有利于提高作物产量,但会增加稻田综合温室效应和温室气体排放强度。鉴于双季稻区中稻面积有增大的趋势,综合环境效益和经济效益,油菜-一季中稻减排增效效果更好。  相似文献   

生地黄与马兜铃配伍缓解马兜铃毒性的研究     

史本栋  魏佳宇  刘金松  孙梦晴  邹连慧  姜晓文  于文会 《中国畜牧兽医》2021,48(6):2221-2229

试验旨在探究生地黄与马兜铃配伍对鸡肝脏和肾脏的影响，为中药配伍解毒提供现代理论依据。将80只雄性雏鸡随机分为10组，分别为对照组，马兜铃高、中、低剂量组，生地黄高、中、低剂量组，马兜铃与生地黄配伍高、中、低剂量组。各组中药经过煎煮、过滤、离心去除杂质，制成煎液。每日灌服给药，连续28 d。采用试剂盒检测谷草转氨酶（AST）、谷丙转氨酶（ALT）、肌酐（Cr）、尿素氮（BUN）肝脏和肾脏功能指标；利用试剂盒检测总抗氧化能力（T-AOC）、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）和丙二醛（MDA）。采集肝脏和肾脏并制备切片观察组织病理学变化。结果显示，与单用马兜铃组相比，马兜铃与生地黄配伍后机体的AST、ALT、Cr和BUN含量显著降低（P<0.05），马兜铃与生地黄配伍后能明显提高机体的T-AOC、SOD和GSH-Px含量；单用马兜铃能引起机体氧化损伤，导致MDA含量显著升高，生地黄与马兜铃配伍后能显著降低MDA含量（P<0.05），减缓马兜铃对机体的氧化损伤；病理结果表明，生地黄与马兜铃配伍后能显著降低马兜铃煎煮液对肝脏和肾脏造成的病理性损伤。综上，与单用马兜铃相比，马兜铃与生地黄配伍联用对鸡肝脏和肾脏造成的损伤有缓解作用，可提高马兜铃的用药安全。  相似文献   

Novel chelant‐based washing method for soil contaminated with Pb and other metals: A pilot‐scale study     

《Land Degradation \u0026amp; Development》2017,28(8):2585-2595

Remediation with chelants can restore metal‐contaminated soils for use as a natural resource. Calcareous soil from Meza Valley, Slovenia, and acidic soils from Arnoldstein, Austria, and Pribram, Czech Republic (with 1,028, 862, and 926 mg ∙Pb∙kg⁻¹, respectively), were washed with 60–100 mmol EDTA per kilogram of air‐dried soil in series of 30 batches (50 kg soil batch⁻¹). The approach involves a novel reaction that incorporates alkaline substitution, precipitation and adsorption of toxic metals on polysaccharides, and chelant acidic precipitation via 83% EDTA (on average) and complete process water recycling (no wastewater was generated). The pH gradient was imposed by Ca(OH)₂ and H₂SO₄, and excess reagent was removed with the remediated soil as CaSO₄, thereby preventing the salification of the recycled waters. Remediation removed 60%, 78%, and 71% of the Pb from the Meza, Arnoldstein, and Pribram soils, respectively, and reduced the Pb bioaccessibility levels in the simulated human gastrointestinal phase by 5.0, 7.7, and 8.1 times. Residual emissions (EDTA, toxic metals) were reduced with soil aging and remediated soil deposition on a reactive permeable barrier. The solid waste generated from the process totaled 10.8 kg tons⁻¹ of the air‐dried soil, and the material/energy costs of remediation reached 20.6 € tons⁻¹. These results demonstrate the robustness, efficiency, and safety of this novel approach.  相似文献   

Contribution To Climate Change Of Forest Fires In Spain: Emissions And Loss Of Sequestration     

Álvaro Enríquez-de-Salamanca 《Journal of Sustainable Forestry》2020,39(4):417-431

ABSTRACT

Forest fires contribute to climate change mainly due to emission of greenhouse gases by biomass burning and loss of sequestration by sink destruction. The average contribution in Spain between 1998 and 2015 was 9,494,910 Mg CO_{2 eq} per year, 23.8% from biomass burning and 76.2% from loss of carbon sequestration, the latter three times higher than the former, although the emissions from combustion are usually the only accounted. Regarding to the vegetation burned, 43.6% of emissions come from forest (17.7% conifers, 4.8% hardwoods and 21.1% Eucalyptus), 53.7% from scrublands and 2.7% from grasslands. The loss of sequestration is 6.6% in the fire year and by 93.4% in previous years. Scrubland burning produces a greater amount of emissions than forests, but forest regeneration is slower, with greater influence on the loss of sequestration. It is essential a forest management focused on increase fire resilience and adaptation to climate change, increase the effectiveness of extinction works to reduce fire damages and implement actions to recover the burnt vegetation, because the loss of sinks is a critical aspect.  相似文献   

克鼠星1号对甘肃鼢鼠毒杀作用测定   总被引：3，自引：0，他引：3  

韩崇选  王明春  杨学军  张宏利  杨清娥 《陕西林业科技》2002,(2):27-31

据测定 ,克鼠星 1号成品灭鼠剂对甘肃鼢鼠的室内杀灭效果为 10 0 % ,最佳致死量为 4 4.6～4 9.5 g/ kg,平均致死时间为 10 6 .5 4h。甘肃鼢鼠 2 4～ 4 8h食毒量与龄级、体重呈负相关 ,且雌鼠大于雄鼠。致死时间与龄级、体重呈正相关 ,与食毒呈负相关。雌鼠中 3年耐药性最强 ,而雄鼠的最弱。最佳致死温度 ,日最低为 10 .6± 0 .4℃ ,最高为 13.2± 2 .5℃ ,平均为 11.7± 1.6℃。  相似文献   

重庆市农业温室气体减排潜力分析   总被引：1，自引：0，他引：1  

王莉玮  赵中金  曾荣  王正奎 《安徽农业科学》2012,(5):2928+3084

农业是重要的温室气体排放源。通过对文献资料和大量研究结果进行分析,得出重庆市农业活动产生的温室气体减排空间巨大。通过推广稻田间歇灌溉可减少稻田甲烷排放15.07万t,约为当前排放量的30%;一个户用沼气每年最大可减少温室气体2.0～4.1t二氧化碳当量;推行缓释肥、长效肥料可减少单位面积农田氧化亚氮1 744.65 t,约为当前排放量的50%。  相似文献   

串珠镰刀菌素的理化性质、毒作用机理及中毒动物概况   总被引：1，自引：0，他引：1  

高思  雷明彦  齐德生  张妮娅  张金凤 《饲料工业》2012,33(8):53-57

串珠镰刀菌素是由多种镰刀菌产生的有毒次级代谢产物。其产毒菌种常侵染玉米、小麦和水稻等禾谷类作物,不仅造成农作物减产,更会危害动物和人类健康。串珠镰刀菌素的毒性主要会造成心脏损伤和免疫力下降,同时也会损伤肝、肾、胰等内脏器官以及骨组织和软骨组织。文章综合论述了串珠镰刀菌素的理化性质、毒作用机理以及中毒动物的病理学检查、组织学检查和临床症状。  相似文献