1.) Explain why the following substances are added to soil by gardeners and farmers. a.) Lime CaO
It increases the pH of soil.Soil that is too acidic presents two different problems for crops. First, the amount of necessary minerals in the soil such as potassium and calcium decreases. Second, aluminum and manganese levels increase to potentially toxic levels below a pH of roughly 5.5.Calcium oxide, addresses the problem. It reacts in water to release calcium ions and hydroxide ions, which raise the pH of the soil.The soil which is too acidic will be neutralised by the lime which is alkaline. H2O + CO2 -> H2CO3
2SO2 + H2O + O2 -> 2H2SO4
4NO2 + 2H2O + O2 -> 4HNO3
H2CO3 + CaCO3 -> 2HCO3- + Ca+2
B) Sulfate of ammonia
Sulfate of ammonia is an important source of nitrogen for plants. Chemical reaction and bacteria in the soil turns ammonium compounds into nitrates which are fertilizers for the plants. Nitrates are very essential for healthy growth of plant. It is also used as an agricultural spray adjuvant for water soluble insecticides, herbicides, and fungicides. The salts’ function is to bind iron and calcium cations that are present in both water and plant cells.
2.)For farmers, soil acidification on their land can be a major problem. What is soil acidification, how is it caused and how is it prevented?
Soil acidification is the build up of hydrogen ions(H+), reducing the pH, therefore the soil becomes too acidic. The donor can be an acid, such as nitric acid and sulfuric acid.The addition of the acids can be due to acid rain and pollution. Many nitrogen compounds, which are added as fertilizer, also acidify soil over the long term because they produce nitrous and nitric acid when oxidized in the process of nitrification. Acidification also occurs when base cations such as calcium, magnesium, potassium and sodium are leached from the soil. This leaching increases with increasing precipitation. Plants take bases from the soil as they grow, donating...
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