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土壤生物体氮的含量、转化及供氮意义 被引量:4
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作者 周建斌 李生秀 李辉桃 《西北农业大学学报》 CSCD 北大核心 1997年第2期106-110,共5页
综述了土壤生物体氮(土壤活体微生物所含氮素)的测定方法,土壤中生物体氮的含量及变化,土壤生物体氮与土壤可矿化氮之间的关系,以及土壤生物体氮的有效性及供氮意义。
关键词 土壤生物体氮 可矿化 测定方法
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田间土壤生物体氮的影响因子研究 被引量:1
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作者 王成 李世清 +4 位作者 王强 田新铃 王志方 杨莲 仝殿荣 《新疆农业大学学报》 CAS 2003年第2期20-24,共5页
在杨凌中等肥力红油土上进行大田试验 ,研究土壤生物体氮的变化及影响因子。试验结果表明 ,不同季节土壤生物体氮含量不同 ,秋季和春季较高 ,初冬居中 ,严冬最低 ,这种变化规律与土壤温度和水分含量变化相一致。施用氮肥和有机肥能显著... 在杨凌中等肥力红油土上进行大田试验 ,研究土壤生物体氮的变化及影响因子。试验结果表明 ,不同季节土壤生物体氮含量不同 ,秋季和春季较高 ,初冬居中 ,严冬最低 ,这种变化规律与土壤温度和水分含量变化相一致。施用氮肥和有机肥能显著增加生物体氮。不施氮时 ,种植油菜和小麦田块土壤中生物体氮显著低于休闲土壤 ,而施氮后 ,则高于休闲土壤 ;种植豌豆不同于其它两种作物 ,不施氮时 ,生物体氮仍然和休闲土壤持平 ,这表明在种植条件下 ,施用氮肥或种植豆科作物对维持土壤生物体氮库具有重要意义。土壤生物体氮不仅耕层远远高于下层 。 展开更多
关键词 田间土壤 生物体氮 影响因子
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作物生长期间土壤可矿化氮的变化 被引量:3
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作者 李世清 李生秀 《土壤侵蚀与水土保持学报》 CSCD 北大核心 1996年第3期73-77,共5页
在陕西杨陵中等肥力的红油土上进行大田试验,定期分层采取土样,测定土壤可矿化氮和生物体氮,研究作物生长期间土壤可矿化氮的变化及其与生物体氮的关系。结果表明,土壤可矿化氮的分布具有明显的层次性,耕层高,下层少;变化具有明... 在陕西杨陵中等肥力的红油土上进行大田试验,定期分层采取土样,测定土壤可矿化氮和生物体氮,研究作物生长期间土壤可矿化氮的变化及其与生物体氮的关系。结果表明,土壤可矿化氮的分布具有明显的层次性,耕层高,下层少;变化具有明显的阶段性,作物生长前期,含量低而稳定,后期显著增加,是前期的2.0倍。施用氮肥对土壤可矿化氮含量无明显影响;施有机肥可使其后期显著增加.作物种类与种植与否对可矿化氮的影响远比采样时期小。培养期间释放的可矿化氮仅是起始时生物体氮的12.0%,两者之间也无密切相关。起始生物体氮似乎难以反映土壤的供氮能力。 展开更多
关键词 田间土壤 可矿化 生物体氮 土壤能力 作物生长期
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Studies on Crystalline Growth of O_2-susceptible Proteins in Space
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作者 董志刚 王耀萍 +4 位作者 韩毅 龚海韵 汪道涌 陆建华 黄巨富 《Acta Botanica Sinica》 CSCD 2001年第3期256-260,共5页
In order to meet the requirement for crystalline growth of O-2-susceptible proteins in space, crystallization conditions on the earth was optimized for the proteins using a simple and suitable device for anaerobic add... In order to meet the requirement for crystalline growth of O-2-susceptible proteins in space, crystallization conditions on the earth was optimized for the proteins using a simple and suitable device for anaerobic addition of the protein samples. Nitrogenase is susceptible to O-2. Delta nifZ MoFe protein from a nifZ deleted strain and MnFe protein from mutant strain UW3 grown on a medium containing Mn were crystallized at the first time in the world using an anaerobic device equipped with plastic bags or using a small simplified box, as a replacement for the cumbersome dry box. And the proteins could be also crystallized far from laboratory by sitting-drop method using a much lighter device. It was equipped with a smaller plastic food bag and a first-aid bag filled with Ar, as a substitute for the cumbersome dry box and the Ar cylinder, respectively. The results showed that the device could meet the requirement for studies on crystal growth of the above anaerobic proteins in space. 展开更多
关键词 O-2-susceptible proteins crystalline growth in space
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Effects of Alternative Nitrogen Management Regimes on Production of Eucalyptus in Tropics and Sub-tropics
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作者 Moses Otuba Johansson Karl-Erik 《Journal of Agricultural Science and Technology(B)》 2014年第5期341-351,共11页
This paper presents the effects of alternative nitrogen management regimes on production of Eucalyptus in tropics and sub-tropics carried out in autumn, 2011. The aim of the study was to review alternative nitrogen ma... This paper presents the effects of alternative nitrogen management regimes on production of Eucalyptus in tropics and sub-tropics carried out in autumn, 2011. The aim of the study was to review alternative nitrogen management regimes that could enhance the positive effects and reduce negative effects of different Eucalyptus species in the perspective of smallholders. Literature review was used to survey the alternative nitrogen management regimes on eucalyptus trees. There was a significant improvement (P ≤ 0.01) in mean annual increment (MAI) as measured at seven years of Eucalyptus tereticornis in the plots planted with only legume, pueraria and stylosanthes, compared to that of the control on altitude 150 m and rainfall of 2,000 mm at the age of seven years, The MAI of Eucalyptus urophylla and Eucalyptus camaldulensis in plots planted with beans and rice shows a significant improvement (P ≤ 0.05) over the control treatment. Only the plots treated with nitrogen fertilizer 550 kg/ha showed significant improvement (P ≤ 0.05) in terms of MAI of Eucalyptus nitens, compared to the control treatment. In general, it can be concluded that as these alternative management regimes enhance productivity of Eucalyptus woodlots, the challenge for the small-scale farmers is on how to manage them sustainably. Therefore, forest policies that take consideration of increasing production of Eucalyptus and managing biodiversity with reference to these alternative management regimes should be developed in tropics and sub-tropics. 展开更多
关键词 EUCALYPTUS legumes management NITROGEN sub-tropics tropics.
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Complete genome sequence of a novel bacteriophage infecting Bradyrhizobium diazoefficiens USDA110 被引量:1
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作者 Junjie Liu Hao Yu +5 位作者 Yong Huang Zhenhua Yu Guoquan Fan Jian Jin Xiaobing Liu Guanghua Wang 《Science China(Life Sciences)》 SCIE CAS CSCD 2018年第1期118-121,共4页
Dear Editor,The nitrogen-fixing symbiotic bacteria, rhizobia are the most important beneficial bacteria in soil, as they form nodules with host legume plants to fix nitrogen to maintain soil fertility and facilitate p... Dear Editor,The nitrogen-fixing symbiotic bacteria, rhizobia are the most important beneficial bacteria in soil, as they form nodules with host legume plants to fix nitrogen to maintain soil fertility and facilitate plant growth. Although these bacteria are critically important to agriculture, bacteriophages of rhizobia (rhizobiophages) are commonly present in soils, rhizosphere,and nodules, which have major influences on the composition and population of rhizobia in soils and affect nodulation and nitrogen fixation. Despite the importance of rhizobiophages,only 23 phage full genomes have been sequenced. 展开更多
关键词 MI
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