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排序方式: 共有481条查询结果,搜索用时 31 毫秒
71.
[目的]探讨氮磷配施的氨挥发规律及机理。[方法]设置5个施磷水平,通过大田试验、盆栽试验和土壤培养试验,研究氮磷配施的氨挥发规律。[结果]磷作基肥氮作追肥时,不同施磷处理的氨挥发速率先从低到高逐渐增至峰值,然后降低,峰值随施磷量增加而增高,最高峰值为2.36 kg/(hm2.d);追施氮肥3、7、12 d后,随着施磷量的增加,土壤中铵态氮含量增加,氨挥发强度增强;土壤脲酶活性比氮磷同为基肥时增强,随施磷量增加呈明显增加趋势。氮磷同为基肥时,单施氮处理不施磷处理的土壤脲酶活性比氮磷同施处理高,随着施磷量的增加,氮磷同施处理的脲酶活性略有增加趋势。[结论]土壤铵态氮含量与氨挥发速率、土壤脲酶活性均有较好的相关性。 相似文献
72.
综述了反刍动物体内氨与尿素代谢的研究进展,阐述了氨在胃肠道的来源和去路,讨论了尿素循环的过程及其影响因素,介绍了研究氨的产生、吸收与尿素循环的方法,探讨了调控尿素循环的途径。综合分析认为,尿素循环利用是反刍动物机体内源氮重吸收中最重要的组成部分,通过减少氨吸收和氨基酸分解代谢来减少日粮氮转化成尿素,或者提高肝脏中合成的尿素及再循环至胃肠道的尿素转化成微生物蛋白质的效率,可提高日粮氮素的利用效率。因此,开展尿素循环规律的研究,以建立实用日粮条件下含氮化合物的整体代谢模型,对调控反刍动物体内氮素营养至关重要。 相似文献
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74.
2017年天津市动物园首次引进大食蚁兽(Myrmecophaga tridactyla),雌、雄各1只,并于2018年7月16日产下1只雌性幼仔。在哺乳期间,雌兽面部出现丘疹状水泡,嗜睡,活动时快速徘徊,显现烦躁状态,四肢明显无力,食欲不佳,易呕吐,反复出血性肠炎。2019年9月,雌兽食量降至健康时的1/3,体重降至35 kg,减少15 kg。血生化检查显示,血氨与治疗后对比异常升高,丙氨酸氨基转移酶升高,红细胞、血红蛋白、血细胞比容偏低。血涂片瑞氏染色可见薄型红血球、卡波德环状小体和偏心红血球。根据实验室检查结果,初步诊断为营养性巨幼细胞贫血合并缺铁性贫血。治疗原则为保肝护肝,补充叶酸、维生素B12和多种矿物质,降低饲料动物性蛋白质含量,调理胃肠道菌群。经过为期1年的治疗调理,该食蚁兽食欲、活动良好,体重增加至45 kg,各项指标趋于正常。 相似文献
75.
76.
K. Fleming MSc E.F. Hessel PD Dr. H.F.A. Van den Weghe Prof. Dr. Ir. 《Journal of Equine Veterinary Science》2008,28(4):223-231
Bedding material is an important factor in determining stable air quality in terms of ammonia formation. The objective of this study was to analyze different bedding materials used for horse stables under standardized conditions, to determine which material is best suited for improving the climate of a stable. The particular concern was a reduction in gaseous ammonia concentrations. Therefore, the following materials were examined: wheat straw, wood shavings, hemp shives, linen shives, wheat straw pellets, and paper cuttings. Twelve containers were constructed in an environmentally controlled room, and the same material was placed into two containers, with the amount of material used being determined by its carbon content. A defined ratio of horse manure/urine mixture was added daily to each container over a period of 14 days. The concentrations of gaseous ammonia, carbon dioxide, nitrous oxide, and water vapor were measured continuously above the bedding within the containers. Means of gaseous ammonia were found to be 178.0 mg/m3 for wheat straw, 155.2 mg/m3 for wood shavings, 144.6 mg/m3 for hemp, 133.7 mg/m3 for linen, 60.3 mg/m3 for straw pellets, and 162.6 mg/m3 for paper cuttings. In conclusion, the results of this study have shown that straw pellets are suitable for horse stables, not only to improve air quality but also, first and foremost, in relation to ammonia binding and ammonia transformation within the bedding material, respectively. However, straw pellets may also have disadvantages. The high substrate temperatures that were measured in straw pellets could favor the growth of pathologic germs that can adversely affect animals' health. 相似文献
77.
氨水处理落叶松的药品着色方法 总被引:1,自引:0,他引:1
刘亚兰 《东北林业大学学报》2005,33(1):101-102
论述了木材着色种类与方法,并针对天然林落叶松和人工林落叶松实木进行药品着色试验,亦即氨水处理试验。探讨了通过不同的处理时间,来获得不同材色的落叶松的具体方法,为落叶松在家具和室内装饰方面的充分应用提供依据。 相似文献
78.
《Plant Production Science》2013,16(3):249-253
AbstractNH3 emission from leaves of three rice (Oryza sativa L.) cultivars, Akenohoshi, Shirobeniya and Kasalath, was examined using a simple open chamber system. In the three cultivars, NH3 emission rate (AER) and NH4+ content of leaves decreased with decreasing NH4+ concentration in the root medium, but these values differed significantly with the cultivar. In the daytime, AER, NH4+ content and glutamine synthetase (GS) activity in leaves changed similarly with maximum values around midday. Akenohoshi showed significantly lower AER and NH4+ content but higher GS activity than Kasalath. The difference in AER among the rice cultivars may be related to the activity of GS involved in photorespiratory NH3 recycling. Akenohoshi can be a breeding material useful for improving N recycling. 相似文献
79.
In Spain, farmers are interested in applying pig (Sus scrofa domesticus) slurry (PS) to their fields throughout the year. During the spring and summer months, ammonia (NH3) volatilization may be high. We studied the potential range of NH3 losses under a warm and a hot period of the year, using available field practices, and two strategies: PS directly incorporated into the soil, in spring (I‐spring); and PS applied by splash‐plate, in summer time (SP‐summer), both to bare soil. Measurements were conducted, after PS application, using the micrometeorological mass balance integrated horizontal flux method. The cumulative NH3‐N volatilization was 35% (I‐spring) and 60% (SP‐summer) of total ammonium nitrogen applied, and half of the total NH3‐N losses happened by 17 h and 8 h, respectively, after application. Incorporation strategy was less effective in avoiding NH3 losses than is described in the literature. This fact has important consequences for the implementation of NH3 mitigation measures in Mediterranean agricultural systems. 相似文献
80.