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E. M. Koriesh and I. H. Abo-Soud
• Right placement.
Nitrogen availability is the single best predictor of N 2 O fluxes in ecosystems [32].
N 2 O emissions are especially high when N fertilizer is applied at rates greater than
plant need. The emission rate grows exponentially with increases in fertilizer rate,
so at higher rates of fertilizer application N 2 O emissions increase disproportionately. Fertilizer formulations also can alter N 2 O emissions. The trend toward using
more urea in may help reduce N 2 O emissions. Fertilizer additives can also reduce
N 2 O emissions. Nitrification inhibitors such as nitrapyrin, which delay the microbial
transformation of soil ammonium to nitrate, can delay the formation of nitrate until
closer to the time that plants can use it [33].
Applying N fertilizer when it is most needed by plants can also help reduce N 2 O
emissions. Also, Placing N fertilizer close to plant roots can reduce N 2 O emissions.
For example, applying urea in narrow bands next to the trees and shrubs in hedges
can reduce N 2 O emissions [34]. An integrated approach is best suited to reduce
N 2 O emissions. The same principles of N fertilizer best management practices for
increased nitrogen use efficiency (NUE) hold true for reducing emissions [35].
1. Apply fertilizer at the economically optimum rate;
2. Use an appropriate fertilizer formulation;
3. Apply as close to the time of plant need as possible; and,
4. Apply as close to the plant’s root zone as possible.
2.5.1 Sulfur Oxides (SO x )
Sulfur oxide (SO 2 ) is the component of greatest concern and is used as the indicator
for the larger group of gaseous sulfur oxides (SO x ). Other gaseous SO x (such as
SO 3 ) are found in the atmosphere at concentrations much lower than SO 2 . The sulfur
oxide is the most voluminous chemically active gas emitted from some industrial
processes such as chemical preparation, refining, pulp-making and solvent extraction
and burning of fossil fuels such as coal, oil and natural gas. Coal-fired power stations,
in particular, are major sources of sulfur dioxide, with coal burning accounts for 50%
of annual emissions, as explained by the Tropospheric Emission Monitoring Internet
Service (TEMIS). But trace amounts of SO 2 exert significant influence on climate.
Large volumes of SO 2 erupted frequently appear to overdrive the oxidizing capacity
of the atmosphere resulting in very rapid warming [36].
A study carried out by Zhang et al. [37] at China conditions (which is one of the
highest countries in, SO 2 emitter in the world [38]) revealed that urban native street
trees have a potential for purifying SO 2 [39]. SO 2 is a major air pollutant in developing countries. They added that many trees are seriously impaired by SO 2 , while
other species can mitigate air pollution by absorbing this gas. Planting appropriate
tree species near industrial complexes is critical for aesthetic value and pollution
mitigation. In their study, six landscape tree species were investigated for their tolerance of SO 2 : Cassia surattensis Burm. f., Ceiba insignis (Kunth) P. E. Gibbs &
E. M. Koriesh and I. H. Abo-Soud
• Right placement.
Nitrogen availability is the single best predictor of N 2 O fluxes in ecosystems [32].
N 2 O emissions are especially high when N fertilizer is applied at rates greater than
plant need. The emission rate grows exponentially with increases in fertilizer rate,
so at higher rates of fertilizer application N 2 O emissions increase disproportionately. Fertilizer formulations also can alter N 2 O emissions. The trend toward using
more urea in may help reduce N 2 O emissions. Fertilizer additives can also reduce
N 2 O emissions. Nitrification inhibitors such as nitrapyrin, which delay the microbial
transformation of soil ammonium to nitrate, can delay the formation of nitrate until
closer to the time that plants can use it [33].
Applying N fertilizer when it is most needed by plants can also help reduce N 2 O
emissions. Also, Placing N fertilizer close to plant roots can reduce N 2 O emissions.
For example, applying urea in narrow bands next to the trees and shrubs in hedges
can reduce N 2 O emissions [34]. An integrated approach is best suited to reduce
N 2 O emissions. The same principles of N fertilizer best management practices for
increased nitrogen use efficiency (NUE) hold true for reducing emissions [35].
1. Apply fertilizer at the economically optimum rate;
2. Use an appropriate fertilizer formulation;
3. Apply as close to the time of plant need as possible; and,
4. Apply as close to the plant’s root zone as possible.
2.5.1 Sulfur Oxides (SO x )
Sulfur oxide (SO 2 ) is the component of greatest concern and is used as the indicator
for the larger group of gaseous sulfur oxides (SO x ). Other gaseous SO x (such as
SO 3 ) are found in the atmosphere at concentrations much lower than SO 2 . The sulfur
oxide is the most voluminous chemically active gas emitted from some industrial
processes such as chemical preparation, refining, pulp-making and solvent extraction
and burning of fossil fuels such as coal, oil and natural gas. Coal-fired power stations,
in particular, are major sources of sulfur dioxide, with coal burning accounts for 50%
of annual emissions, as explained by the Tropospheric Emission Monitoring Internet
Service (TEMIS). But trace amounts of SO 2 exert significant influence on climate.
Large volumes of SO 2 erupted frequently appear to overdrive the oxidizing capacity
of the atmosphere resulting in very rapid warming [36].
A study carried out by Zhang et al. [37] at China conditions (which is one of the
highest countries in, SO 2 emitter in the world [38]) revealed that urban native street
trees have a potential for purifying SO 2 [39]. SO 2 is a major air pollutant in developing countries. They added that many trees are seriously impaired by SO 2 , while
other species can mitigate air pollution by absorbing this gas. Planting appropriate
tree species near industrial complexes is critical for aesthetic value and pollution
mitigation. In their study, six landscape tree species were investigated for their tolerance of SO 2 : Cassia surattensis Burm. f., Ceiba insignis (Kunth) P. E. Gibbs &