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Improving cropping systems may help mitigate greenhouse gas emissions. This study determined the carbon footprint of durum wheat (Triticum turgidum L.) produced in diverse cropping systems. Durum was grown in rotation systems which had different combinations of oilseed, pulse, and cereal crops at five site-years in Saskatchewan, Canada. Total greenhouse gas emissions from the decomposition of crop residues along with various production inputs were used for the estimation of carbon footprint. On average, emissions from the decomposition of crop straw and roots accounted for 25% of the total emissions, those from the production, transportation, storage, and delivery of fertilizers and pesticides to farm gates and their applications 43%, and emissions from farming operations 32%. Durum wheat preceded by an oilseed crop (Brassica napus or Brassica juncea) the previous year had carbon footprint of 0.33 kg CO2e kg−1 of grain, or 7% lower than durum in cereal-cereal-durum system. Durum preceded by a biological N-fixing crop (Cicer arietinum chickpea, Lens culinaris lentil, or Pisum sativum pea) the previous year lowered its carbon footprint by 17% compared with durum preceded by a cereal crop. Durum produced in a pulse-pulse-durum system had carbon footprint 0.27 kg CO2e kg−1 of grain, 34% lower than durum grown in cereal-cereal-durum systems. Diversifying cropping systems with oilseeds and biological N-fixers significantly lowered carbon footprint of durum wheat. 相似文献
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中国西北冬小麦和棉花生长对气候变暖的响应 总被引：5，自引：1，他引：4
利用甘肃省西峰市和敦煌市农业气象观测站1981～2004年的观测资料,初步探讨了气候变暖对冬小麦和棉花生长的影响.结果表明:春季极端低温的升高使冬小麦返青期和棉花的播种期明显提前,后期极端高温的升高使冬小麦成熟提前,而极端低温的变暖使棉花停止生长延迟.冬小麦越冬期～返青期的缩短与期间极端低温显著相关,而乳熟～成熟期的缩短与期间极端高温显著相关,返青期～拔节期和开花～乳熟期呈现延长的趋势且均与期间极端低温呈显著相关.棉花播种期～五叶期随期间极端低温的升高而缩短;五叶～现蕾、吐絮～停止生长期和全生育期呈现延长的趋势,且分别与期间极端低温显著相关.冬小麦产量与越冬期间的最低气温呈显著正相关,但返青～孕穗和乳熟～成熟期间的最高气温与产量呈显著负相关.棉花产量与开花以前的平均最低气温呈显著正相关;霜前花产量随十月最低气温的升高而显著增加.生育期间的增温特别是十月最低气温的变暖对本地区棉花生产产生了积极的作用,而生育后期的高温对冬小麦的高产则极为不利. 相似文献
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过氧化氢诱导紫彩血蛤排放精卵及其胚胎发育的研究 总被引：4，自引：0，他引：4
采用浓度为0.1～10‰的H_2O_2海水处理紫彩血蛤,能诱导其排放精卵,排放率为60%～80%,其中H_2O_2浓度在0.5%～1‰之间时效果较好,排放率高达80%,并且诱导排放时间较短。文章还叙述了紫彩血蛤胚胎发育过程中性腺、精子、卵子以及胚胎发育各期的形态。 相似文献
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双抗对紫彩血蛤幼虫发育的影响 总被引：1，自引：0，他引：1
本文研究了青霉素钾盐和硫酸链霉素(双抗)混合使用对紫彩血蛤(Nutallia olivacea)幼虫发育的影响。结果表明:1～80ppm的双抗均有很好的抑菌效果,均可显著地提高幼虫的存活率,最高可提高52％,最低也可提高38％,同时对幼虫生长和变态均有明显的促进作用。其中以2～4ppm效果最好,幼虫生长最快,变态率最高;高浓度组对幼虫也无明显的副作用,幼虫生长速度、变态率和存活率也都高于对照组。 相似文献
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[目的]选育新型十字花科蔬菜。[方法]利用从日本引进的菜薹（Brassica campestris L.var.utilis）和花椰菜（B.oleracea L.var.italica）的远缘杂交材料,经系统选育育成的一种食用花茎、花蕾的新型珍稀蔬菜蕾薹菜。[结果]蕾薹菜植株生长势强,株高4050cm,一次分枝712条,分枝长20 cm左右,单枝重（除去小叶）2030 g,秋季种植采收期可达60 d,露地产量为15.0020.00 t/hm2。花茎及花蕾（分枝）营养极为丰富,维生素C含量高达1 040.00 mg/kg（FW）,各种矿物质含量均较高,既可熟食也可生食,生食鲜嫩爽口,口感极佳。[结论]选育出了一种优质的新型十字花科蔬菜蕾薹菜。 相似文献
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Root distribution patterns in the soil profile are the important determinant of the ability of a crop to acquire water and nutrients for growth. This study was to determine the root distribution patterns of selected oilseeds and pulses that are widely adapted in semiarid northern Great Plains. We hypothesized that root distribution patterns differed between oilseed, pulse, and cereal crops, and that the magnitude of the difference was influenced by water availability. A field experiment was conducted in 2006 and 2007 near Swift Current (50°15′N, 107°44′W), Saskatchewan, Canada. Three oilseeds [canola (Brassica napus L.), flax (Linum usitatissimum L.), mustard (Brassica juncea L.)], three pulses [chickpea (Cicer arietinum L.), field pea (Pisum sativum L.), lentil (Lens culinaris)], and spring wheat (Triticum aestivum L.) were hand-planted in lysimeters of 15 cm in diameter and 100 cm in length which were pushed into soil with a hydraulic system. Crops were evaluated under low- (natural rainfall) and high- (rainfall + irrigation) water conditions. Vertical distribution of root systems was determined at the late-flowering stage. A large portion (>90%) of crop roots was mainly distributed in the 0-60 cm soil profile and the largest amount of crop rooting took place in the top 20 cm soil increment. Pulses had larger diameter roots across the entire soil profile than oilseeds and wheat. Canola had 28% greater root length and 110% more root tips in the top 10 cm soil and 101% larger root surface area in the 40 cm soil under high-water than under low-water conditions. In 2007, drier weather stimulated greater root growth for oilseeds in the 20-40 cm soil and for wheat in the 0-20 cm soil, but reduced root growth of pulses in the 0-50 cm soil profile. In semiarid environments, water availability did not affect the vertical distribution patterns of crop roots with a few exceptions. Pulses are excellent “digging” crops with a strong “tillage” function to the soil due to their larger diameter roots, whereas canola is more suitable to the environment with high availability of soil water that promotes canola root development. 相似文献
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LIN Derong WU Shuirong LI Zhiyong .Research Institute of Forestry Policy Information Chinese Academy of Forestry Beijing P.R.China .Economics School Sh ong Institute of Business Technology Yantai P.R.China 《中国林业科技(英文版)》2010,(3):1-9
Forestry and forest ecosystem are highly sensitive to climate change.At present,studies about the responses of forests to climate change in China are more focused on physical influences of climate change.This paper firstly divided the key impact factors of climate change on forest and forestry developing into direct factors and indirect factors,and then made an assessment on climate change affecting future forestry development from the aspect of forest products and ecological services.On this basis,the adap... 相似文献
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A Method Suitable for Extracting Genomic DNA from Animal and Plant——Modified CTAB Method 总被引：1，自引：0，他引：1
YAN Miao-miao WEI Guang-cheng PAN Xiao-hong MA Huai-lei LI Wei-zhen Yantai Campus of Binzhou Medical College Yantai 《（《农业科学与技术》）编辑部》2008,(2)
[Objective] The study aimed to introduce a rapid and effective method that is suitable for extracting genomic DNA from animal and plant. [Method] The genomic DNAs were extracted from tender leaves of 24 peanut cultivars and from the liver,lung and kidney of white mouse through the specifically modified CTAB method. The DNAs were run on agarose gel,next detected by DNA/Protein analyzer. Finally PCR amplification was conducted to detect the quality of DNAs extracted using the modified CTAB method. [Result] The clear and orderly bands were observed in gel detection,and the values of OD260/OD280 for DNAs extracted via modified CTAB method were between 1.77-1.83. The DNAs performed well in PCR amplification. [Conclusion] The DNAs extracted by modified CTAB method could satisfy the requirement of PCR amplification. 相似文献