Effect of Foliar GA3 and ABA Applications on Reactive Oxygen Metabolism in Black Currants (Ribes nigrum L.) During Bud Para-dormancy and Secondary Bud Burst     

Huo Jun-wei  Fei Xiao-hui  Gang Hui-xin  Zhang Yan  Gong Xiao-nan  Li Song-lin  Bian Chun-yang  Yu Gary-Gao  Qin Dong 《东北农业大学学报(英文版)》2021,28(4):1-11

The secondary bud burst can cause around 10％-20％ yield losses in black currants, an economically important crop in parts of Europe, Asia and North America. The ...  相似文献   

多层二次风配风对玉米秸秆颗粒燃烧降低NOx产率及结渣的影响     

柳善建  王帅超  易维明  李永军  冯祥东 《农业工程学报》2021,37(15):222-231

秸秆类生物质具有碱金属及灰分含量高的特性,燃烧时灰分容易团聚结块而影响燃烧室内的配风及燃料的燃烧。本文设计了一种具有多层二次风配风的生物质燃烧试验装置,以玉米秸秆颗粒为燃料,研究了不同一二次风分级配比、多层二次风配比对烟气中CO、NOx等污染物浓度、燃烧效率及灰分结渣率的影响规律。结果表明：当采用一二次风分级配风时,能够显著降低烟气中NOx的浓度,烟气中CO和NOx的浓度变化趋势相反,呈现一种竞争关系。二次风位置较高或下层二次风量的减少,都易导致玉米秸秆颗粒燃烧不完全,CO浓度显著提升。与对照组相比,二次风多层配风下,燃烧室内各测点的温度和烟气中NOx浓度均有所降低,最低NOx浓度排放放生在W1工况（空气系数为1.2,一、二次风配比为60%：40%时,下、中、上二次风按（1/2,0,1/2））,约150 mg/m3。当采用二次风多层配风时,结渣率大幅度下降,最低为4.5%。W1工况的NOx浓度和结渣率均较低,综合评价为最优工况。常用的硅比指数G、碱酸比、Na含量指数、碱性指数Alc等4种结渣指数,均不能正确预测因燃料燃烧区温度T1变化而造成的结渣倾向变化,为此在硅比指数G中引入燃料燃烧区温度T1作为变量,修正后的硅比指数Gt可以很好地对玉米秸秆颗粒因燃料燃烧区温度T1引起的结渣倾向变化进行预测。  相似文献   

氮锌配施对不同玉米品种灌浆期生理特性和籽粒氮锌含量的影响     

张盼盼  邵运辉  刘京宝  乔江方  李川  张美微  黄璐 《核农学报》2022,36(5):1042-1051

提高粮食作物中可食部分的锌生物有效性是解决人体缺锌的重要措施。为研究氮锌肥料施用对玉米籽粒锌营养的影响,本研究以郑单958和谷神玉66为试验材料,在大田条件下研究3个氮水平(90、180 和225 kg N·hm^-2)和2个喷锌处理(0和4.5 kg·hm^-2 ZnSO₄·7H₂O)下玉米籽粒产量和氮锌含量以及灌浆期叶片生理特性的变化。结果表明,吐丝后,与施氮量90 kg·hm^-2处理相比,施氮量180和225 kg·hm^-2处理提高了吐丝后穗位叶SPAD值及硝酸还原酶(NR)、谷氨酰胺合成酶(GS)、碳酸酐酶(CA)、超氧化物歧化酶(SOD)活性和灌浆后期PSⅡ综合性能指数(PI),降低了丙二醛(MDA)含量。施锌能提高吐丝后穗位叶CA、SOD、过氧化物酶(POD)、过氧化氢酶(CAT)活性和灌浆后期SPAD值和PI,降低MDA含量。2个品种相比,谷神玉66灌浆后期穗位叶SPAD值、叶片初始荧光(F_o)和最大荧光(F_m)较高,而灌浆前期穗位叶PI和吐丝后NR、CA、SOD以及POD活性则以郑单958较高。施氮量为90 kg·hm^-2时,玉米籽粒产量平均为8.55 t·hm^-2,随着施氮量增加,玉米籽粒产量显著提高。籽粒中氮含量以施氮量180 kg·hm^-2时最高,为14.85 g·kg^-1。施氮量90和180 kg·hm^-2时,籽粒锌含量平均为27.2 mg·kg^-1,显著高于施氮量225 kg·hm^-2处理。与不施锌相比,喷锌后玉米籽粒产量未有显著变化,籽粒中氮、锌含量分别增加了11.7%和18.0%。郑单958籽粒产量较谷神玉66提高了3.8%,籽粒氮锌含量则分别减少了11.9%和5.3%。综合来看,施氮量为180 kg N·hm^-2时,与喷施ZnSO₄·7H₂O 4.5 kg·hm^-2 配合施用能够增强玉米灌浆期叶片SPAD和荧光特性,提高氮锌代谢关键酶活性,增强氧自由基清除系统酶活性,减弱膜脂过氧化作用的伤害,促进籽粒中氮、锌的吸收和累积。本研究结果可为玉米生产中优化锌生物强化措施提供理论依据。  相似文献   

Application of urease inhibitor improves protein composition and bread‐baking quality of urea fertilized winter wheat     

Azin Rekowski  Monika A. Wimmer  Bernd Hitzmann  Bernhard Hermannseder  Heike Hahn  Christian Zrb 《植物养料与土壤学杂志》2020,183(2):260-270

Background: Nitrogen losses is an economic problem for wheat production and a high risk to the environment. Therefore, improved N fertilizer management is a key to increasing the N efficiency and minimizing N losses. To increase N efficiency, enhanced fertilizers such as urea combined with urease inhibitor can be used. Aims: The aim of present study was to evaluate the effects of different N forms on grain storage protein subunits in winter wheat and to examine whether the observed changes correlate with parameters of baking quality. Methods: The investigation was performed over two consecutive years at two locations in Germany. Protein subunits were analyzed by SDS‐PAGE. Results: Protein concentrations were similarly increased after fertilization with ammonium nitrate and urea + urease inhibitor. Analysis of the individual storage protein fractions indicated that both fertilizers specifically enhanced ω‐gliadins and HMW glutenins, but the effect was more pronounced in the ammonium nitrate treatment. Application of urea + urease inhibitor had greater influence on the protein composition and resulted in higher specific baking volume as well as the best fresh keeping ability, in comparison with urea treatment. Conclusion: Considering that the urea + urease inhibitor treatment resulted in almost comparable improvements of NUE and baking quality, with the additional benefit of reduced N losses in combination with easy handling, urea + urease inhibitor can be recommended as a viable alternative to both urea alone and ammonium nitrate treatments. This opens up an opportunity for the reduction of N loss in wheat production when use of urea is preferred.  相似文献   

喷施山梨醇螯合钙对花生生长及钾、钙、镁吸收的影响     

李腾升  魏倩倩  王文昊  崔玉照  谭慧婷  孙伟  杨羽  张欢洋  韩传浩  颜冬云 《土壤》2022,54(6):1117-1123

为探究不同山梨醇螯合钙喷施浓度对花生生长及养分吸收的影响,采用大田试验,以花育22号为试材,在施基肥基础上设置5个钙素喷施浓度处理(以Ca²⁺计,单位g/L):0 (CK)、1.4 (T1)、1.6 (T2)、1.8 (T3)与2.0 (T4),测定了各处理对花生光合作用、收获期产量、品质、各器官干物质积累量及钾、钙、镁含量的影响。结果表明：(1)与CK处理相比,喷施山梨醇螯合钙提高了叶片SPAD值,促进了花生光合作用,尤其在结荚期;(2)喷施山梨醇螯合钙能提高花生产量及粗脂肪、粗蛋白含量,其中T2处理较CK处理分别提高11.48%、5.74%、7.82%;(3)喷施山梨醇螯合钙能够显著增加籽仁干物质积累量,有效提高花生生殖器官干物质占比,降低营养器官干物质分配比例,以T3处理改善效果较为突出,其次是T2处理;(4)喷施山梨醇螯合钙对花生各器官钾、钙、镁含量的影响不同,但总体上促进了花生对养分的吸收。主成分分析结果表明,喷施山梨醇螯合钙显著影响了花生生长发育。综合来看,喷施Ca²⁺浓度为1.6～1.8 g/L的山梨醇螯合钙对花生增产提质效果更...  相似文献   

坡度对降雨径流挟沙能力影响的模拟试验     

王照润  高建恩  周凡凡  王鹭  张元元  高哲  李兴华 《水土保持学报》2023,37(1):97-102,113

高陡边坡降雨径流侵蚀输移能力是一个重要的科学问题。通过室内模拟降雨试验研究相同雨强不同坡度和坡长条件下的降雨径流侵蚀输移规律。结果表明：(1)试验条件下,水深与水力坡度的1/3次方呈负相关,与坡长的3/5次方呈正相关,流速与水力坡度和水深呈幂函数增加;(2)相同雨强裸坡条件下,径流含沙量与水力坡度的1/2次方呈正相关,与坡长的4/5次方呈正相关。水流挟沙能力约与水力坡度的1/2次方呈正相关。(3)降雨径流的水流紊动扩散作用与重力作用的比值较明渠水流偏大,表明雨滴打击的紊动作用较明显,给出挟沙能力公式。与常用的河流泥沙挟沙能力公式比较,系数偏大,指数偏小。研究成果对深入分析降雨径流侵蚀输移的机制具有重要意义。  相似文献   

基于MCR模型的城镇生态安全格局构建和建设用地开发模式   总被引：3，自引：6，他引：3  

邱硕  王宇欣  王平智  林聪 《农业工程学报》2018,34(17):257-265

近年来,在中国城市土地开发的顶层设计中越发强调生态空间的重要性,充分识别城市生态安全格局并探讨建设用地空间扩展格局成为划定生态保护红线、确定城市开发边界和"三规合一"空间管制等政策实施的迫切需求。该文以唐山市为例,基于"生态过程—格局"理论和GIS的空间相关性分析、距离分析和叠加分析等方法,从综合水安全、地质灾害预警、生物生境保护、水土保持、游憩安全5个方面,整合构建了底线安全格局、缓冲安全格局和最优安全格局3种不同等级的综合生态安全格局。该文在MCR模型算法引入不同等级"源"的权重系数,以综合生态安全格局为阻力因子,并结合城镇中心的吸引力、主要道路的吸引力和政策调控(区域开发重点)等城镇用地扩展影响因素,得到在不同约束条件下的区域空间扩展阻力面,分别确定了唐山市在"生态安全约束型""经济增长主导型"和"生态与经济并重"3种模式下城镇空间可能的发展范围,经过多方案比较,"生态与经济并重"城镇建设用地空间发展模式是未来城镇健康有序发展的最优模式,这种发展模式既有利于减少大规模、高强度的城镇化和工业化过程所造成的城市发展和环境保护之间的用地冲突,也可为城市用地布局规划和生态红线划定提供科学依据。  相似文献   

电解质浓度对土壤吸附铜离子时氢离子释放的影响     

邹献中  张超兰  魏岚  宁建凤  杨少海 《土壤学报》2011,48(5):964-970

研究了不同铜离子浓度、不同电解质浓度情况下,吸附铜离子时氢离子释放对两种可变电荷土壤和4种恒电荷土壤悬液pH的影响。研究结果表明,除了黄棕壤外,含铁量越高,由于吸附铜离子后所引起的土壤ΔpH最大值越小。加入的铜离子浓度为10-4 mol L-1时,铜离子吸附对中和曲线形状没有根本影响。在较低浓度时,铜离子吸附时氢离子的释放较少;而在较高浓度时,当体系pH大于一临界值时,开始释放大量氢离子。氧化铁是引起恒电荷土壤和可变电荷土壤在吸附铜离子时氢离子释放差异产生的主要原因。电解质浓度的变化对恒电荷土壤和可变电荷土壤吸附铜离子后中和曲线变化影响有很大的区别,含铁量越高,电解质浓度对土壤吸附铜离子后的氢离子释放的影响越小。  相似文献   

Considering sink strength to model crop production under elevated atmospheric CO₂     

Eline Vanuytrecht  Dirk Raes 《Agricultural and Forest Meteorology》2011,151(12):1753-1762

Climatic changes and elevated atmospheric CO₂ concentrations will affect crop growth and production in the near future. Rising CO₂ concentration is a novel environmental aspect that should be considered when projections for future agricultural productivity are made. In addition to a reducing effect on stomatal conductance and crop transpiration, elevated CO₂ concentration can stimulate crop production. The magnitude of this stimulatory effect (‘CO₂ fertilization’) is subject of discussion. In this study, different calculation procedures of the generic crop model AquaCrop based on a foregoing theoretical framework and a meta-analysis of field responses, respectively, were evaluated against experimental data of free air CO₂ enrichment (FACE) environments. A flexible response of the water productivity parameter of the model to CO₂ concentration was introduced as the best option to consider crop sink strength and responsiveness to CO₂. By varying the response factor, differences in crop sink capacity and trends in breeding and management, which alter crop responsiveness, can be addressed. Projections of maize (Zea mays L.) and potato (Solanum tuberosum L.) production reflecting the differences in responsiveness were simulated for future time horizons when elevated CO₂ concentrations and climatic changes are expected. Variation in future yield potential associated with sink strength could be as high as 27% of the total production. Thus, taking into account crop sink strength and variation in responsiveness is equally relevant to considering climatic changes and elevated CO₂ concentration when assessing future crop production. Indicative values representing the crop responsiveness to elevated CO₂ concentration were proposed for all crops currently available in the database of AquaCrop as a first step in reducing part of the uncertainty involved in modeling future agricultural production.  相似文献   

三种类型农田排水沟渠氮磷拦截效果比较   总被引：11，自引：0，他引：11  

王岩  王建国  李伟  薄录吉  杨林章 《土壤》2009,41(6):902-906

为了了解太湖地区不同类犁农田排水沟渠对N、P拦截效果的影响,分别在野外构建了3种类型的农田排水沟渠,即生态沟渠、混凝土沟渠和土质沟渠.研究了不同进水N、P浓度、不同水力停留时间和不同进水流速条件下,3种类型沟渠的N、P拦截效果.结果表明:在水力停留时间分别为24 h和48 h静态试验以及在固定进水流速的动态试验中,沟渠对不同进水N、P浓度的N、P去除牢大小顺序是:生态沟渠、土质沟渠和混凝土沟渠,其中,生态沟渠明显优于其他沟渠.在固定进水浓度的条件下,沟渠在不同水力停留时间下的N、P去除率大小顺序为;生态沟渠、土质沟渠和混凝土沟渠,其中,生态沟渠明显好于其他沟渠.在高、低两种进水流速和固定进水浓度条件下.生态沟渠在低进水流速下的N、P去除率明显优于其他沟渠.在不同进水浓度条件下,生态沟渠最佳水力停留时间为48 h.  相似文献