Previous Year Question
Consider the following statements.
Agricultural soils release nitrogen oxides into environment.
Cattle release ammonia into environment.
Poultry industry releases reactive nitrogen compounds into environment.
Which of the statements given above is/are correct?
1 and 3
2 and 3
Only 2
1, 2 and 3
Correct Answer: D
Detailed Solution
The application of nitrogenous fertilizers and organic manure in agriculture increases the quantity of reactive nitrogen in soil.
Soil microorganisms may produce nitrous oxide and other nitrogen oxides during nitrification and denitrification.
Therefore, agricultural soils release nitrogen oxides into the environment. Hence, Statement 1 is correct.
Nitrous oxide is a powerful and long-lived greenhouse gas.
A portion of the nitrogen consumed by cattle is not converted into milk or body growth and is excreted through urine and dung.
Urea present in urine may break down through microbial action to produce ammonia.
Therefore, ammonia may be emitted from animal housing, manure storage and manure applied to fields. Hence, Statement 2 is correct.
Poultry manure and litter contain uric acid and other nitrogen-bearing substances.
Their decomposition may release ammonia and other reactive nitrogen compounds into the environment. Therefore, Statement 3 is correct.
Ammonia may react with acidic compounds in the atmosphere to form ammonium salts, which become part of PM2.5.
Excess reactive nitrogen may cause eutrophication in water bodies and acidification of soils and ecosystems.
Nitrogen oxides may also contribute to the formation of ground-level ozone and secondary particulate matter.
Applying fertilizers in the right quantity, at the right time and in the right place can reduce nitrogen emissions from agricultural soils.
Improved animal feed, covered manure storage and rapid incorporation of manure into soil can reduce ammonia emissions.
Managing the moisture and pH of poultry litter and scientifically treating waste can also help control reactive nitrogen.