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首页> 外文学位 >Gaseous nitrogen and odour emissions following manure application under grassland and cultivated systems.
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Gaseous nitrogen and odour emissions following manure application under grassland and cultivated systems.

机译：在草地和耕作系统上施肥后，气态氮和气味的排放。

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摘要

Livestock manure is a valuable source of plant nutrients, however, if poorly managed it can have negative environmental impacts. The major environmental impacts and health concerns associated with manure are the loss of nitrogen (N) in the form of nitrate (NO3), ammonia (NH3) and nitrous oxide (N2O), as well as odour emissions. Laboratory and field experiments were conducted in Truro and Great Village, Nova Scotia to evaluate the effect of several management strategies on NH3, N2O and odour emissions. The strategies evaluated include; (i) use of a nitrification inhibitor (dicyandiamide), (ii) soil liming, (iii) slurry application rate, (iv) soil water status, (v) slurry dilution, and (vi) simulated rainfall soon after slurry application. The study also evaluated the effects of meteorological conditions on NH3, N 2O and odour emissions, for the purpose of identifying the most appropriate conditions under which manure can be applied with minimum emissions. Results showed that dicyandiamide had no effect on either NH3 or N 2O emissions. Liming soil to a pH ≥ 6.3 decreased N2O, but increased NH3 emissions. Generally, N2O emissions from the field experiments were low (∼5 g N ha-1 d-1) even with high (180 t ha-1) slurry application rates. This was due to low soil NO3- -N (5 mg kg-1 soil) contents caused by slow nitrification activity on these acidic soils. Additionally, estimated indirect N2O emissions (i.e., emissions due to volatilised NH3) were higher than direct emissions. Increasing slurry application rate increased NH3 losses and to a lesser extent odour emissions, but had no effect on N2O emissions. Applying slurry to wet soils increased NH 3 losses by 8% compared to dry soil, but had no effects on N2O and odour emissions. Slurry dilution and simulated rainfall reduced NH 3 losses on average by 41 and 45%, respectively, but had no effect on N2O emissions. With regard to odour, dilution reduced odour emissions on average by 27%, while simulated rainfall increased odour emissions by 15%. Ammonia losses increased with higher air and soil temperature, net radiation, evapotranspiration and vapour pressure deficit, while N2O emissions were not affected by the recorded meteorological variables. Meanwhile, odour emissions increased with higher windspeed, net radiation and evapotranspiration. Both NH3 and odour emissions can therefore, be reduced by applying slurry during cool and calm conditions, however, such conditions may increase odour persistence. The fact that estimated indirect N2O emissions were higher than direct emissions suggests that more effort should be directed towards reducing NH3 losses following application of slurry on these acidic soils.; In addition, field experiments were performed from 2003 to 2005 at Streets Ridge (SR), Cumberland County, Nova Scotia and Bio-Environmental Engineering Centre (BEEC), Truro, Nova Scotia to evaluate the impact of tillage on NH 3, N2O, denitrification rates, ratios of denitrification end-products (N2O:N2O+N2), and soil and drainage water NO3--N concentrations following surface application of beef and dairy manure. Over the two seasons, manure incorporation in the conventional tillage (CT) reduced NH3 loss on average by 86% at SR and 78% at BEEC relative to no-tillage (NT). At both sites and both seasons, denitrification rates and N2O emissions in NT were generally higher than in CT. Conversely, N2O:N2O+N2 ratios were lower in NT, indicating more complete reduction of N2O to N2. Similarly, soil and drainage water NO3 --N concentrations were generally lower in NT. Thus, NT can be used to reduce NO3--N leaching to groundwater, albeit with trade-offs.
机译：畜禽粪便是植物营养的重要来源，但是，如果管理不善，会对环境造成负面影响。与粪便相关的主要环境影响和健康问题是硝酸盐（NO3），氨气（NH3）和一氧化二氮（N2O）形式的氮（N）的损失以及气味的排放。在新斯科舍省的特鲁罗和大村庄进行了实验室和现场实验，以评估几种管理策略对NH3，N2O和气味排放的影响。评估的策略包括； （i）使用硝化抑制剂（双氰胺），（ii）土壤石灰，（iii）泥浆施用率，（iv）土壤水状况，（v）泥浆稀释和（vi）泥浆施用后不久的模拟降雨。该研究还评估了气象条件对NH3，N 2O和气味排放的影响，目的是确定最合适的条件，在此条件下可以以最小的排放量施用肥料。结果表明，双氰胺对NH3或N 2O排放均无影响。将土壤石灰化至pH≥6.3会减少N2O，但会增加NH3排放。通常，即使在高（180 t ha-1）泥浆施用量的情况下，田间试验产生的N2O排放量也较低（〜5 g N ha-1 d-1）。这是由于在这些酸性土壤上硝化活性缓慢导致土壤NO3- -N（<5 mg kg-1土壤）含量低。此外，估计的间接N2O排放量（即由于挥发的NH3引起的排放量）高于直接排放量。提高浆料施用率会增加NH3的损失，并在较小程度上增加气味的排放，但对N2O的排放没有影响。与干土相比，在湿土上施用泥浆可使NH 3损失增加8％，但对N2O和气味排放没有影响。稀浆稀释和模拟降雨分别平均减少NH 3损失41％和45％，但对N2O排放没有影响。关于气味，稀释后平均减少了27％的气味排放，而模拟降雨增加了15％的气味排放。氨气损失随着空气和土壤温度，净辐射，蒸散量和蒸气压亏空的增加而增加，而N2O排放不受所记录的气象变量的影响。同时，随着风速，净辐射和蒸散量的增加，气味排放量也增加。因此，可以通过在凉爽和平静的条件下施加浆料来减少NH3和气味的排放，但是，此类条件可能会增加气味的持久性。估计的间接N2O排放量高于直接排放量这一事实表明，在这些酸性土壤上施用泥浆后，应加大力度减少NH3的损失。此外，从2003年至2005年，在新斯科舍省坎伯兰县Streets Ridge（SR）和新斯科舍省特鲁罗的生物环境工程中心（BEEC）进行了田间试验，以评估耕作对NH 3，N2O和反硝化的影响施用牛粪和奶牛粪后，反硝化终产物的比率，反硝化最终产物的比率（N2O：N2O + N2）以及土壤和排水中的NO3--N浓度。在两个季节中，相对于免耕（NT），常规耕作（CT）中的粪便施用使SR处的NH3损失和BEEC处的平均NH3损失平均减少了78％。在两个站点和两个季节，NT中的反硝化率和N2O排放通常高于CT。相反，NT中N2O：N2O + N2的比例较低，表明N2O更完全地还原为N2。同样，NT中的土壤和排水NO3--N浓度通常较低。因此，尽管可以权衡取舍，但NT可用于减少NO3--N向地下水的淋溶。

著录项

  • 作者

    Mkhabela, Manasah Sibusiso.;

  • 作者单位

    Dalhousie University (Canada).;

  • 授予单位 Dalhousie University (Canada).;
  • 学科 Engineering Agricultural.
  • 学位 Ph.D.
  • 年度 2007
  • 页码 198 p.
  • 总页数 198
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 农业工程;
  • 关键词

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